ALBERT

Description: 〈p〉Publication date: Available online 1 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): S. Monzani, A. Andreazza, M. Citterio, P. Fontana, M. Ianna, T. Lari, V. Liberali, F. Ragusa, C. Sbarra, A. Sidoti, A. Stabile〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Monochromatic X and gamma rays are a standard calibration tool for semiconductor detector. For finely segmented pixel detectors, like the ones foreseen for HL-LHC detector upgrades, the single pixel spectrum is affected by charge sharing across nearby pixels, due to diffusion and the finite range of photoelectrons, resulting in a low energy continuum below the photoelectric peak. In this paper a systematic simulation study will be presented. The shape of the transition between the photoelectric peak and the continuum is determined by diffusion and needs to be unfolded for a correct estimation of the energy resolution. Simulation results are compared with data collected with different high-resistivity CMOS devices with 50 × 250 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mi mathvariant="normal"〉μ〈/mi〉〈/math〉m〈sup〉2〈/sup〉 pixel size and photon energies between 13 and 60 keV. They show a good agreement, highlighting the potential usage of the whole single pixel spectrum to derive device characteristics.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 209〈/p〉 〈p〉Author(s): Magdalena Broda, Carmen-Mihaela Popescu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Wood has been extensively used as a material for different applications over the years, therefore the understanding of different degradation processes in various environments is of great importance. In this study, the infrared spectroscopy, X-ray diffraction and chemometric methods were used to evaluate and compare the structure of archaeological and artificially degraded oak wood. The results clearly show that modifications in the structure of archaeological wood are related to the position of the material in the log (sapwood and heartwood), thus the extent of wood degradation. To identify the possible factors influencing these effects, the control wood samples were exposed to artificial white rot biodegradation with 〈em〉Coriolus〈/em〉 (〈em〉Trametes〈/em〉) 〈em〉versicolor〈/em〉 and to alkali treatment (with NaOH solution). Due to the structural similarities between biodegraded wood and control or archaeological samples, this type of decay is likely to occur during natural ageing along with degradation produced by other environmental factors. Further, no real similarity was identified between the alkali treated wood and archaeological samples, indicating that such degradation does not affect wood under natural conditions.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518309909-ga1.jpg" width="295" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 209〈/p〉 〈p〉Author(s): Prathap Reddy Patlolla, Nakshi Desai, Sharad Gupta, Bhaskar Datta〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The interaction of fluorescent dyes with serum proteins has garnered significant interest owing to potential for non-covalent labeling and imaging applications. In this work, dimeric benzothiazole-based trimethine cyanine dyes are synthesized and their interaction with bovine serum albumin studied. The dimeric cyanine dyes mainly exist as H-dimers and H-aggregates in aqueous solution. A combination of absorbance, fluorescence, circular dichroism spectroscopy and atomic force and fluorescence microscopy indicate the formation of dye-BSA complexes. Binding of one of the dimeric dyes on BSA with a K〈sub〉a〈/sub〉 of 1.49 × 10〈sup〉5〈/sup〉 M〈sup〉−1〈/sup〉 results in disruption of dye self-aggregates and unfolding of the dyes into the monomeric or open conformation. Fluorescence enhancement experienced by the dimeric dyes upon interaction with BSA is superior to that registered by Thioflavin T. Surfactant SDS has been used to further tune the self-aggregation of the dimeric dye resulting in a 200-fold fluorescence enhancement in presence of BSA. Interaction of a dimeric dye with BSA under conditions favoring protein aggregation is found to result in faster dye binding and the resulting fluorescence enhancement is easily visualized by fluorescence microscopy. The interaction of a dimeric cyanine dye aggregate with BSA is promising for non-covalent labeling applications in sharp contrast to the monomeric dye counterpart.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518309818-ga1.jpg" width="322" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 209〈/p〉 〈p〉Author(s): Huan Zong, Xijiao Mu, Jiangcai Wang, Huifang Zhao, Ying Shi, Mengtao Sun〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, we report time resolved fluorescence resonance energy transfer (FRET) using femtosecond ultrafast transient absorption spectroscopy. The lifetimes of FRET are strongly dependent on the molecular concentration and ratio of donor and acceptor. Also, in the FRET, photoinduced intermolecular charge transfer (PICT) is also investigated theoretically. The driving force for PICT in FRET system equals the reorganization energy, which gives barrier-less charge transfer according to Marcus theory. The rates of PICT in the FRET system can be estimated with our simplified Marcus equation. Our results of PICT in FRET system provide a new efficient way for the charge transfer in donor-acceptor system.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518309855-ga1.jpg" width="296" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 209〈/p〉 〈p〉Author(s): Kai Zhang, Lei Cai, Jianzhong Fan, Yuchen Zhang, Lili Lin, Chuan-Kui Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Recently, thermally activated delayed fluorescence (TADF) molecules have attracted great attention since nearly 100% exciton usage efficiency was obtained in TADF molecules. Most TADF molecules used in organic light-emitting diodes are in aggregation state, so it is necessary to make out the intermolecular interaction on their photophysical properties. In this work, the excited-state properties of the molecule AI-Cz in solid phase are theoretically studied by the combined quantum mechanics and molecular mechanics (QM/MM) method. Our results show that geometry changes between the ground state (S〈sub〉0〈/sub〉) and the first singlet excited state (S〈sub〉1〈/sub〉) are limited due to the intermolecular π-π and CH-π interactions. The energy gap between S〈sub〉1〈/sub〉 and the first triplet excited state is broadened and the transition properties of excited states are changed. Moreover, the Huang-Rhys factors and the reorganization energy between S〈sub〉0〈/sub〉 and S〈sub〉1〈/sub〉 are decreased in solid phase, because the vibration modes and rotations are hindered by intermolecular interaction. The non-radiative rate has a large decrease in solid phase which improves the light-emitting performance of the molecule. Our calculation provides a reasonable explanation for experimental measurements and highlights the effect of intermolecular interaction on excited-states properties of TADF molecules.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518309867-ga1.jpg" width="499" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 209〈/p〉 〈p〉Author(s): Tinggui Chen, Xueying Pei, Yongkang Yue, Fangjun Huo, Caixia Yin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cysteine (Cys) is not only the central matter of sulfur metabolism in cells but also the only amino acid with reduced thiol group in 20 kinds of natural amino acids. In animal cells, Cys is taking part in many important and essential biological functions including protein synthesis, detoxification and metabolism. The development and application of fluorescent probes for the detection of Cys have attracted more and more attention and interest. Herein, we report a new fluorescent probe 〈strong〉NFA〈/strong〉 that utilized naphthyl carboxy fluorescein as fluorophore and acryloyl group as reaction site for Cys specific detection. The probe essentially has weak fluorescence. Cys addition to 〈strong〉NFA〈/strong〉 containing system induced distinct enhanced fluorescence emission which was attributed to the nucleophilic reaction of cysteine and acryloyl to release the fluorophore. The signal fluorescent response detection system allows 〈strong〉NFA〈/strong〉 to be a reliable tool for Cys detection with low detection limit (0.58 μM). And 〈strong〉NFA〈/strong〉 has been successfully applied for Cys imaging specifically in live Hela cells, which promotes the probe as a potential tool to understand the pathology of Cys related diseases.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S138614251830982X-ga1.jpg" width="339" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 31 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): K. Dropiewski, A. Minns, M. Yakimov, V. Tokranov, P. Murat, S. Oktyabrsky〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Picosecond timing of energetic charged particles and photons is a challenge for many high-energy physics and medical applications. InAs Quantum Dots (QDs) embedded in GaAs matrix are expected to have singular scintillation properties. The advantages come from highly efficient energy conversion, as well as from fast electron capture and radiative recombination in QDs. We present design considerations and demonstration of an ultrafast, high photon yield room-temperature semiconductor scintillator. Due to the high refractive index of GaAs, the scintillator is fabricated in the form of a 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mn〉20〈/mn〉〈mspace width="1em"〉〈/mspace〉〈mi mathvariant="normal"〉μ〈/mi〉〈mi mathvariant="normal"〉m〈/mi〉〈/math〉 thick planar waveguide with an integrated InGaAs photodiode. QD luminescence of about 60% efficiency at room temperature has been shown, and modal attenuation stabilized at 1 cm〈sup〉−1〈/sup〉. Scintillation responses from 5.5 MeV alpha particles show an extremely fast decay time of 280 ps, a collection efficiency of 11% and a time resolution of 60 ps. This data confirms the unique potential properties of this scintillation detector.〈/p〉〈/div〉

Description: 〈p〉Publication date: 21 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 915〈/p〉 〈p〉Author(s): Jingyu Tang, Changdong Deng, Xi Wu, Shuai Li, Yuwen Wu, Wen Kang, Xiyin Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper presents the design and prototyping of novel structure magnets–simplified multipole magnets, one octupole and one dodecapole. The field measurements of the prototypes show very good agreement with the numerical field calculations. The octupole prototype can produce either an anti-symmetric or a symmetric field distribution. Magnets with this novel structure can supply much higher saturation fields, e.g. doubled pole-gap strength of 0.6 T for the dodecapole prototype. The intrinsic field errors for the integrated field distribution are within 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si15.gif"〉〈mo〉±〈/mo〉〈/math〉1% for a rectangular shape of good field region, which are acceptable for some applications such as beam spot uniformization. Some key technical issues of building the magnets are also discussed. The success of the prototyping will pave the way for applications of the magnet family.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 1 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): Noriaki Kawaguchi, Go Okada, Kentaro Fukuda, Takayuki Yanagida〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We have tested high-temperature responses of prototype neutron detectors equipping Ce-doped lithium silicate glass (GS20), LiCaAlF〈sub〉6〈/sub〉:Ce, LiCaAlF〈sub〉6〈/sub〉:Eu, LiCaAlF〈sub〉6〈/sub〉:Ce, Na, and LiCaAlF〈sub〉6〈/sub〉:Eu, Na. These detectors were prepared by coupling of the scintillators to a photomultiplier tube (PMT) for high-temperature environments (R1288, Hamamatsu). In the pulse height spectra under thermal neutron irradiation in the temperature range from 25 °C to 150 °C, peak heights of all the samples decreased with increasing temperatures. The decreasing rates for the peak heights of LiCaAlF〈sub〉6〈/sub〉 scintillators were lower than that of GS20. The LiCaAl〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉F〈/mi〉〈/mrow〉〈mrow〉〈mn〉6〈/mn〉〈/mrow〉〈/msub〉〈/math〉scintillators can be used in the temperature range from 25 °C to 150 °C.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 1 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): A. Loi, A. Lai, G.F. Dalla Betta, R. Mendicino, S. Vecchi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The experimental conditions in future High Luminosity LHC experiments require new detector systems with increased performances compared to the current state of the art. In this context, increasing spacial resolution and including time measurement with a resolution of less than 50 ps for particle tracking systems can avoid false track reconstruction due to event pile up. For this kind of future tracking detectors the 3D silicon sensor technology appears as a good option. In this context the TIMESPOT initiative was launched. Concerning the development of the sensor, different geometrical solutions have been explored and simulated to optimize the timing response of the single pixel sensor using Sentaurus TCAD. The configuration with the best electric field characteristics for timing was selected for signal simulation. In order to compensate the very time-consuming behavior of TCAD simulations, a faster charge transport simulator with TCAD and Geant4 support is under development. Further sensor configurations, including a first primitive capacitive and resistive load, were also simulated and evaluated. This paper shows a general overview of the project with particular attention to the silicon sensor development. First results are presented.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 913〈/p〉 〈p〉Author(s): S. Mehdi Hashemi, Ali Negarestani〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, the performance of two GEM-type structures for the detection of alpha particle tracks in gaseous detectors based on SQS mode is presented. The operation of these structures was investigated in the presence of air, pure argon and P10 gas. By increasing the applied voltage to GEM-type plates beyond a certain value, each GEM-type’s through-hole individually entered to the SQS mode, when detector operated in the P10 gas. This mode was followed by the appearance of visible streamers in the space of holes exposed to alpha radiation. Two types of Thick Gas Electron Multipliers (TGEM) and Electron Multiplier Assemblies (EMA) with different geometries, as well as a cascade configuration of EMAs, were designed and constructed. Depending on the hole diameters in these structures, the location of the input beams can be determined optically with a specific resolution.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 1 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): G. Silvestre, on behalf of FOOT collaboration〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The goal of the FOOT (FragmentatiOn Of Target) experiment is to measure the fragmentation cross section of protons into H, C, O targets at beam energies of interest for hadrontherapy (50–250 MeV for protons and 50–400 MeV/u for Carbon ions) (Tommasino et al., 2015 [1]; FOOT CDR Conceptual Design, 0000 [2]). Given the short range of the fragments, an inverse kinematic approach has been chosen, hence requiring precise tracking capabilities for charged ions. One of the foreseen experiment subsystems will be the MSD (Microstrip Silicon Detector), composed of three 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mi〉x〈/mi〉〈/math〉–〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si2.gif"〉〈mi〉y〈/mi〉〈/math〉 measuring planes. In this work we evaluate the suitability of standard double-sided microstrip detectors, coupled to an high dynamic range readout chip, to be used for this task. The results about cluster signal, signal/noise, and dynamic range of readout chip are encouraging, and confirm the suitability of this class of sensors to be used in the FOOT experiment.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 919〈/p〉 〈p〉Author(s): Xiurong Li, Huihai He, Gang Xiao, Xiong Zuo, Shaohui Feng, Lingyu Wang, Cong Li, Mohsin Saeed, Zhen Cao, Xiangdong Sheng, Ning Cheng, for the LHAASO collaboration〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this paper, novel methods are presented to measure the optical properties of the cylindrical water Cherenkov detector with high-reflectivity and diffuse reflection dominated Tyvek material as the inner surface. The mean transmission distance of photons between each reflection in the cylindrical water Cherenkov detector (the mean step length), is constant when there is a sufficient number of photons with random directions in the tank. The time distribution of the photons collected by the photomultiplier tube (PMT) in the water Cherenkov detector is approximately exponential, and the decay factor of the time distribution is determined by the absorption length of photons in the water, the reflectivity of the inner Tyvek surface, the mean step length of photons reflected in the tank, and the ratio of reflective Tyvek area to the total inner surface area. By considering the principles of photon propagation in the water Cherenkov detector, we developed novel methods to measure the water absorption length, Tyvek reflectivity, and mean step length of photons in the tank. The water absorption length and Tyvek reflectivity can be measured simultaneously by changing the height of the water, while the step length and Tyvek reflectivity in air can be measured simultaneously by changing the area of Tyvek, and the mean step length of photons can also be measured even all other parameters unknown. The proposed novel methods are supported by the deduction of formulae and verified by GEANT4 simulations and the prototype experiment.〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 210〈/p〉 〈p〉Author(s): Chinduluri Sravani, Mohsin Y. Lone, Prakash C. Jha, K.I. Sathiyanarayanan, Akella Sivaramakrishna〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A new series of 2‑styryl phenanthro[9,10‑〈em〉d〈/em〉]oxazoles was readily accessible from the condensation reaction of 9,10‑phenanthroquinone with cinnamaldehydes in the presence of lactic acid. All these styryl dyes were isolated in good yields and characterized by various analytical and spectroscopic techniques. One of the dyes containing 〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉NO〈sub〉2〈/sub〉 group (〈strong〉3d〈/strong〉) was structurally characterized by single crystal X-ray analysis. These dyes displayed emission in blue to green region with larger Stokes shift values characteristic to the nature of substituents. In addition, positive solvatochromic trend was observed by increasing the solvent polarity suggestive of a more stabilized polar excited state. Moreover, the addition of trifluoroacetic acid leads to a prominent blue-shift in visible and emission color changes owing to the protonation of the nitrogen atom of oxazole moiety. Among the all, the oxazole derivative having 〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉NMe〈sub〉2〈/sub〉 group (〈strong〉3b〈/strong〉) exhibits good response to acidic pH in the range of 3.0 to 5.6 with a good linearity upon decreasing the pH from 8.0 to 2.16. The absorption studies were further supported by density functional theory calculations.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518309880-ga1.jpg" width="430" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 209〈/p〉 〈p〉Author(s): Anxin Jiao, Xuejian Dong, Hua Zhang, Linlin Xu, Yue Tian, Xiangdong Liu, Ming Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ultrasensitive detection of pesticide residues on agricultural products using surface-enhanced Raman spectroscopy (SERS) is of significant interest in food security. Herein, worm-like AuAg nanochains with highly interconnected ultrafine (~6.2 nm) bimetallic particles were developed as an excellent SERS nanosensor via laser-assisted strategy. The SERS detection limit of thiram molecules on apple surfaces is about 10〈sup〉−7〈/sup〉 M (0.03 ppm), which is about 200 times lower than the maximal residue limit (MRL, 7 ppm) in fruit prescribed by the U.S. Environmental Protection Agency (EPA). Importantly, the established excellent linear relationships between the SERS intensities and thiram concentrations can sensitively monitor the slight variation of pesticide residues in agriculture.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518309843-ga1.jpg" width="331" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 208〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: 15 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 209〈/p〉 〈p〉Author(s): Manjushree M., Revanasiddappa H.D.〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bupropion hydrochloride (BPH) an antidepressant and widely used to treat addiction of nicotine. The actual protein existing in blood plasma for the vehicle of exogenous and endogenous substances is human serum albumin 〈em〉i〈/em〉.〈em〉e〈/em〉. HSA. The interaction of BPH with HSA was examined by molecular docking, multiple spectroscopy's such as fluorescence (emission, synchronous and three-dimensional), UV–vis (ultraviolet–visible), FT–IR (Fourier transform infrared) and CD (circular dichroism) at physiological pH 7.40 at 286, 296 and 306 K. BPH was particularly bind to HSA through forces called hydrogen bonds and vander Waals at site I (IIA) which was confirmed from negative values of thermodynamics calculated by van't Hoff equation and docking studies in addition to site marker analysis. This interaction was spontaneous and exothermic process. Secondary structure including conformation of HSA changes after interaction with BPH was revealed from CD and FT–IR (Fourier self-deconvolution to curve fitting), UV–vis, 3D and synchronous florescence techniques. Forster's theory (non–radiation energy transfer) was applied to calculate the distance from tryptophan of HSA to BPH. This interaction involves static quenching (Stern–Volmer and Modified Stern–Volmer equations) with larger binding constant values were in the range 10〈sup〉5〈/sup〉 confirming that strong interaction was exists between BPH and HSA. The interference of bio-active Mg〈sup〉2+〈/sup〉, Cu〈sup〉2+〈/sup〉, Zn〈sup〉2+〈/sup〉, Ca〈sup〉2+〈/sup〉 and Fe〈sup〉2+〈/sup〉 metal ions on this interaction was also analysed.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518309806-ga1.jpg" width="410" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 15 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): N. Cartiglia, R. Arcidiacono, M. Ferrero, M. Mandurrino, H.-F.W. Sadrozinski, V. Sola, A. Staiano, A. Seiden〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The combination of precision space and time information in particle tracking, the so called 4D tracking, is being considered in the upgrade of the ATLAS, CMS and LHCb experiments at the High-Luminosity LHC, set to start data taking in 2024-25. Regardless of the type of solution chosen, space–time tracking brings benefits to the performance of the detectors by reducing the background and sharpening the resolution; it improves tracking performances and simplifies tracks combinatorics. Space–time tracking also allows investigating new physics channels, for example it opens up the possibilities of new searches in long-living particles by measuring accurately the time of flight between the production and the decay vertexes. The foreseen applications of 4D tracking in experiments with very high acquisition rates, for example at HL-LHC, add one more dimension to the problem, increasing dramatically the complexity of the read-out system and that of the whole detector design: we call 5D tracking the application of 4D tracking in high rate environments.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 913〈/p〉 〈p〉Author(s): George Kitis, Vasilis Pagonis〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Experimental Thermoluminescence (TL) glow curves for most dosimetric materials are composites, consisting of weakly or strongly overlapping peaks. The ability to discriminate between two overlapping peaks defines the resolution of a TL glow curve. Although the concept of resolution has been defined and used widely in many areas of science, there have been no previous attempts to define and study the resolution of overlapping TL peaks. In this work the resolution parameter R is defined in terms of the geometrical characteristics of TL peaks. A large number of TL glow curves consisting of two peaks were numerically evaluated for various degrees of overlapping between them. These numerically generated glow curves were analyzed by a computerized glow curve deconvolution analysis, in order to determine the reliability of the deconvolution results as a function of the resolution parameter R.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): S. Zhao, G. Lioliou, S. Butera, M.D.C. Whitaker, A.M. Barnett〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A Commercial-Off-The-Shelf (COTS) 4H-SiC p-n photodiode (sold as a UV detector) was investigated as detector of electrons (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si34.gif"〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉β〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈/mrow〉〈/msup〉〈/math〉 particles) over the temperature range 100 °C to 20 °C. The photodiode had an active area of 0.06 mm〈sup〉2〈/sup〉. The currents of the photodiode were measured in dark condition and under the illumination of a 〈sup〉63〈/sup〉Ni radioisotope 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si34.gif"〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉β〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈/mrow〉〈/msup〉〈/math〉 particle source (endpoint energy = 66 keV). The photodiode was then coupled to a custom-made low-noise charge-sensitive preamplifier to make a direct detection particle counting electron spectrometer. 〈sup〉63〈/sup〉Ni 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si34.gif"〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉β〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈/mrow〉〈/msup〉〈/math〉 particle spectra were accumulated with the spectrometer operating at temperatures up to 100 °C. The quantum efficiency of the photodiode as well as the spectrum expected to be detected were calculated via Monte Carlo simulations produced using the CASINO computer program. Comparisons between the simulated and detected 〈sup〉63〈/sup〉Ni 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si34.gif"〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉β〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈/mrow〉〈/msup〉〈/math〉 particle spectra are presented. The work was motivated by efforts to apply COTS technologies to develop low-cost space science instrumentation; a low-cost electron spectrometer of this type could be included on a university-led CubeSat mission for space plasma physics and magnetosphere experiments.〈/p〉〈/div〉

Description: 〈p〉Publication date: 11 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 911〈/p〉 〈p〉Author(s): M. Sharma, J. Nattress, I. Jovanovic〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Design of deuterium–tritium (DT) neutron generator facilities requires a careful assessment of radiation shielding. In the models of such facilities an isotropic distribution of neutron flux produced by the neutron generator is usually assumed. However, prior studies have shown that neutron flux surrounding the neutron generator can be anisotropic. This anisotropy results mostly from the design of the generator tube, as well as the angular dependence of DT fusion reaction cross section. In this work, the angular neutron flux was measured for a standard commercially available DT generator (Thermo Fisher Scientific, Model P211) using an organic scintillator and a significant degree of anisotropy was confirmed to exist. The experimentally determined flux was then used in Monte Carlo simulations to examine the impact of anisotropy on the effectiveness of radiation shielding. Although the shielding effectiveness is not considerably affected by the anisotropy, the dose rates in air around the unshielded generator can be significantly different from those predicted when an assumption of isotropic flux is made. These considerations need to be included in modeling of the dose rate around the generator in neutron generator facilities that employ typical neutron generators, which exhibit some degree of anisotropy in neutron flux.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): David Longuevergne〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The different processes at the origin of the dependence of the surface resistance with the RF magnetic field are still not fully understood. Several models have emerged since many years to explain the drop of the quality factor 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si96.gif"〉〈msub〉〈mrow〉〈mi〉Q〈/mi〉〈/mrow〉〈mrow〉〈mn〉0〈/mn〉〈/mrow〉〈/msub〉〈/math〉 (commonly called Q-drop) of a superconducting cavity versus the accelerating gradient. Experimental data are commonly fitted by applying a coarse approximation to convert the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si96.gif"〉〈msub〉〈mrow〉〈mi〉Q〈/mi〉〈/mrow〉〈mrow〉〈mn〉0〈/mn〉〈/mrow〉〈/msub〉〈/math〉 (a global property) into a surface resistance (local property). Extracting accurately the surface resistance from experimental data requires to take into account the RF field distribution over the accelerating structure contrary to what is commonly done in the community. Assuming a field dependent surface resistance does not allow anymore to use the well-known formula 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈msub〉〈mrow〉〈mi〉Q〈/mi〉〈/mrow〉〈mrow〉〈mn〉0〈/mn〉〈/mrow〉〈/msub〉〈mo〉=〈/mo〉〈mi〉G〈/mi〉〈mo〉∕〈/mo〉〈mi〉R〈/mi〉〈/math〉〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si4.gif"〉〈msub〉〈mrow〉〈/mrow〉〈mrow〉〈mi mathvariant="normal"〉s〈/mi〉〈/mrow〉〈/msub〉〈/math〉. This paper gives a procedure to perform an accurate conversion of the quality factor measured during a cavity test into a surface resistance to avoid any error in the evaluation of fitting parameters due to the geometry.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 15 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): S. Roy, S. Rudra, S. Shaw, S. Chatterjee, S. Chakraborty, R.P. Adak, S. Biswas, S. Das, S.K. Ghosh, S.K. Prasad, S. Raha〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Study of the stability of gain and energy resolution for a triple GEM detector has been performed under continuous radiation of X-ray with high rate, using premixed gas of Argon and CO〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈msub〉〈mrow〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈/math〉 in 70/30 ratio and conventional NIM electronics. A strong 〈sup〉55〈/sup〉Fe X-ray source is used for this study. The novelty of this study is that for the stability test same source is used to irradiate the GEM chamber and to monitor the spectrum. The radiation is not collimated to a point but exposed to a larger area. Effect of temperature and pressure on these parameters are also studied. The detail method of measurement and the first test results are presented.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): T. Washimi, M. Kimura, M. Tanaka, K. Yorita〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A two-phase argon detector has high discrimination power between electron recoil and nuclear recoil events based on the pulse shape discrimination and the ionization/scintillation ratio (S2/S1). This character is very suitable for the dark matter search to establish the low background experiment. However, the basic properties of S2/S1 of argon are not well known, as compared with xenon. We report the evaluation of S2/S1 properties with a two-phase detector at drift-fields of 0.2–3.0 kV/cm. Finally, the discrimination power against electron recoil background of S2/S1 is discussed.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): A. Natochii, L. Burmistrov, F. Addesa, O. Bezshyyko, D. Breton, V. Chaumat, G. Cavoto, S. Dubos, Y. Gavrikov, F. Iacoangeli, J. Maalmi Di Bello, S. Montesano, V. Puill, R. Rossi, W. Scandale, A. Stocchi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A method to characterise the quality of a fused silica surface using a 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si4.gif"〉〈mi〉β〈/mi〉〈/math〉-source is presented. Two fused silica bars (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si2.gif"〉〈mn〉5〈/mn〉〈mo〉×〈/mo〉〈mn〉10〈/mn〉〈mo〉×〈/mo〉〈mn〉400〈/mn〉〈mspace width="1em"〉〈/mspace〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉mm〈/mi〉〈/mrow〉〈mrow〉〈mn〉3〈/mn〉〈/mrow〉〈/msup〉〈/math〉) were fabricated for the Cherenkov detector for proton Flux Measurement installed at vacuum chamber of the Super Proton Synchrotron at CERN. The resolution of such device is defined by the collection efficiency of the Cherenkov light, which is produced by relativistic charged particles in the fused silica. Thus, the surface quality of the radiator should be as good as possible to avoid light losses. The method is based on the scanning of the radiator surface with a 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈msup〉〈mrow〉〈/mrow〉〈mrow〉〈mn〉90〈/mn〉〈/mrow〉〈/msup〉〈mi〉S〈/mi〉〈mi〉r〈/mi〉〈/math〉 radioactive source and measurements of the Cherenkov light rate, detected by a PMT attached to the quartz bars. The data have been compared with a Monte-Carlo simulation, providing an estimation of the radiator’s probability of the total internal reflection and inefficient area at the edges of the bars.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 15 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): M. Usami, G. Boca, P.W. Cattaneo, M. De Gerone, F. Gatti, M. Nakao, M. Nishimura, W. Ootani, M. Rossella, Y. Uchiyama〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We studied the impact of radiation damage on scintillation counters read out by six SiPMs connected in series focusing on their time resolution. Six SiPMs from AdvanSiD were irradiated step by step with a 37 MBq 〈sup〉90〈/sup〉Sr source. At the integrated dose expected at the end of the MEG II experiment, the time resolution at 30 °C was measured to be worse by 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si29.gif"〉〈mo〉∼〈/mo〉〈/math〉29%. However, the deterioration is found to be reduced to 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si29.gif"〉〈mo〉∼〈/mo〉〈/math〉6% at 10 °C since thermal dark noise is suppressed. We also tested the effect of connecting in series differently damaged SiPMs. We observed a position dependence of the time center in a counter, which worsened the time resolution.〈/p〉〈/div〉

Description: 〈p〉Publication date: 11 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 911〈/p〉 〈p〉Author(s): Haeryong Yang, Gyujin Kim, Heung-Sik Kang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The hard X-ray free electron laser at the Pohang Accelerator Laboratory (PAL-XFEL) in the Republic of Korea achieved a saturation of free electron laser (FEL) beam at 14.5 keV with an unprecedented intensity of 2.8E+11 photons per pulse. Successfully maintaining a very small emittance electron beam along the 700-m long linac, maximizing the spectral overlap of undulator radiation along the undulator line by the undulator radiation spectrum analysis, and optimal matching between the electron beam and photon beam through the 100-m long undulator line have allowed saturation and reliable operation of a 14.5 keV FEL beam.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 15 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): F. Abudinen, K. Ackermann, P. Ahlburg, M. Albalawi, O. Alonso, L. Andricek, R. Ayad, V. Babu, Y. Bai, T. Bilka, R. Blanco, M. Boronat, A. Bozek, C. Camien, A. Caldwell, V. Chekelian, B. Deschamps, A. Dieguez, J. Dingfelder, Z. Doležal〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Belle II experiment will run with a reduced beam asymmetry and a factor of 40 higher instantaneous luminosity compared to the Belle experiment. To cope with this and to be able to perform high precision vertex measurements for charge conjugation parity violating processes, a pixel detector based on DEPFET technology will be installed in the center of Belle II. Its basic properties and the DAQ chain are presented in this article.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): Zdzisław Dębicki, Karol Jędrzejczak, Jacek Karczmarczyk, Marcin Kasztelan, Ryszard Lewandowski, Jerzy Orzechowski, Jacek Szabelski, Maria Szeptycka, Przemysław Tokarski〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉We performed measurements of thermal and non-thermal neutron flux in underground laboratories in Gran Sasso, Italy and in Slanic Prahova, Romania. The measurements were made with a set of helium counters: bare for thermal neutrons and covered by blocks of moderator for higher energy neutrons. We found that thermal neutron flux in Slanic is four times smaller than in Gran Sasso, probably due to lack of alpha-radioactive sources in the surrounding rocks. In contrast, the flux of higher energy neutrons in Slanic proved to be 1.4 times higher than in Gran Sasso, which can be explained by higher cosmic muon flux in Slanic.〈/p〉 〈p〉Our result for thermal neutron flux is lower than results of most of the previous measurements carried out in LNGS laboratory but thanks to a different method of analysis the reliability of our results is very high. The result for higher energy neutrons agrees with average energy spectrum resulting from previous measurements.〈/p〉 〈p〉Our measurements in Slanic were the first ones ever performed in this laboratory, and can be used as a reference by future experiments.〈/p〉 〈/div〉

Description: 〈p〉Publication date: 11 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 911〈/p〉 〈p〉Author(s): Graeme Turkington, Kelum A.A. Gamage, James Graham〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Strontium-90 is one of the primary beta-emitting radionuclides found at nuclear decommissioning sites. Monitoring its activity in the environment is of utmost importance given its radiotoxicity. Current procedures for the beta detection of strontium-90 are time consuming, produce secondary waste and expensive. There is a demand for real-time in situ radiostrontium monitoring in groundwater at nuclear decommissioning sites. This paper presents a review of existing techniques for strontium-90 monitoring and examines a novel approach through direct beta detection with a gallium arsenide photodiode based detector. A proof of concept detector was modelled in the physics simulation software, Geant4, and evaluated as candidate for in situ detection of beta emitting radionuclides. The simulation results indicate that the detector is physically capable of counting 89.86% of incident 0.546 MeV electrons from a 1 mm range in water. This validation will provide the basis for further development of an in situ beta detector.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 15 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): A. Di Mauro, on behalf of the ALICE Collaboration〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉ALICE, the CERN LHC experiment devoted to the study of the QGP (Quark-Gluon Plasma) properties, will undergo a comprehensive upgrade during the second long shutdown of the LHC (in 2019-2020) to enhance the capability for high precision measurements of rare processes at low transverse momenta (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈msub〉〈mrow〉〈mi〉p〈/mi〉〈/mrow〉〈mrow〉〈mi〉T〈/mi〉〈/mrow〉〈/msub〉〈/math〉). One of the key elements of the upgrade strategy is the novel, high-resolution, ultra-light Inner Tracking System (ITS) consisting of seven concentric layers of Monolithic Active Pixel Sensors (MAPS) covering a total active area of 10 m〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si42.gif"〉〈msup〉〈mrow〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msup〉〈/math〉 segmented in 12.5 Gpixels. This paper presents an overview of the detector components, the most relevant characterisation results and the status of the detector construction.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 15 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): N. Karpushkin, D. Finogeev, M. Golubeva, F. Guber, A. Ivashkin, A. Izvestnyy, V. Ladygin, S. Morozov, A. Kugler, V. Mikhaylov, A. Senger〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Compressed Baryonic Matter (CBM) experiment at the future Facility for Antiproton and Ion Research (FAIR) is aimed to explore the QCD phase diagram in the region of high baryon densities. The Projectile Spectator Detector (PSD) is the forward hadron calorimeter that will be used in the CBM to measure the event centrality as well as the reaction plane orientation in heavy-ion collisions in the beam energy range of 2–11 〈em〉A〈/em〉GeV with beam interaction rates up to 10 MHz. The supermodule consisting of 9 modules has been assembled to explore the performance of the PSD. Its response has been studied with proton beams in the momentum range 2–10 GeV/c at the CERN Proton Synchrotron (PS) T9 and T10 beam lines. For the first time, the energy resolution and the linearity of the response have been measured at such low energies. The PSD operation under radiation conditions at the CBM, as well as the results of one PSD module measurements with irradiated photodetectors are discussed.〈/p〉〈/div〉

Description: 〈p〉Publication date: 11 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 911〈/p〉 〈p〉Author(s): Jan Grzegorz Hajnrych, Philippe Filliatre, Benoît Geslot〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A comparison between a few models of fission fragment penetration in several gases used in fission chambers is presented. To verify the energy loss of fission fragments, a comparison methodology was developed. It is based on comparative analysis of range experiments from third party publications with currently available models. We compared results from the SRIM code, the ICRU parametrization model implemented in Geant-4 and the LSS model. Albeit they are based on different hypotheses about the underlying physics that are not specific to fission fragments, those models reproduce fairly well the trend and order of magnitude of experimental data. Thanks to effective use of semi-empirical correlation fitted over large number of points, the SRIM code gives the closest results to experimental data: thus it is the model of choice for predicting and interpreting fission chambers’ signal.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 15 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): V. Cindro, S.H. Abidi, A.A. Affolder, M. Arratia, B. Ciungu, K. Dette, Z. Dolezal, C. Escobar, V. Fadeyev, C. García, I.M. Gregor, K. Hara, L.B.A. Hommels, Y. Ikegai, P. Kodys, G. Kramberger, J. Kroll, C. Lacasta, V. Latonova, D. Madaffari〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Miniature sensors with external dimensions of 10 mm x 10 mm were produced together with full-size sensors for the innermost ring (R0) of the end-cap part in the upgraded ATLAS inner tracker (ITk). AC- and DC-coupled n-type strips with three different pitches (wide, default and narrow) were processed on high-resistivity p-type FZ silicon substrates by Hamamatsu Photonics. The miniature sensors were irradiated with 70-MeV protons at CYRIC, Tohoku University (Japan) and reactor neutrons at the Jožef Stefan Institute (Slovenia) to three different 1-MeV neutron equivalent fluences: 0.5, 1 and 2 x 10〈sup〉15〈/sup〉〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈msub〉〈mrow〉〈mi〉n〈/mi〉〈/mrow〉〈mrow〉〈mi mathvariant="normal"〉eq〈/mi〉〈/mrow〉〈/msub〉〈/math〉cm〈sup〉−2〈/sup〉. The upper fluence range exceeds the highest anticipated in the innermost part of the ATLAS ITk-Strips over the HL-LHC lifetime (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si2.gif"〉〈mo〉∼〈/mo〉〈/math〉1.25 × 10〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈msup〉〈mrow〉〈/mrow〉〈mrow〉〈mn〉15〈/mn〉〈/mrow〉〈/msup〉〈/math〉n〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si39.gif"〉〈msub〉〈mrow〉〈/mrow〉〈mrow〉〈mi mathvariant="normal"〉eq〈/mi〉〈/mrow〉〈/msub〉〈/math〉cm〈sup〉2〈/sup〉). The charge collection in the test sensors was evaluated systematically using a 〈sup〉90〈/sup〉Sr 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si5.gif"〉〈mi〉β〈/mi〉〈/math〉-source and an Alibava analogue readout system at reverse-bias voltages up to 1000 V.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 15 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): P. Cardarelli, G. Paternò, G. Di Domenico, E. Consoli, M. Marziani, M. Andreotti, F. Evangelisti, S. Squerzanti, M. Gambaccini, S. Albergo, G. Cappello, A. Tricomi, M. Veltri, O. Adriani, R. Borgheresi, G. Graziani, G. Passaleva, A. Serban, O. Starodubtsev, A. Variola〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉ELI-NP-GBS is a high-brilliance gamma source that will produce monochromatic beams in the energy range 0.2-19.5 MeV through inverse Compton scattering. In order to obtain a monochromatic beam a collimation of the emission is necessary. Depending on the energy, the angular aperture required to provide the design bandwidth 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mi〉Δ〈/mi〉〈/math〉E/E=0.5% is between 70 and 700 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si2.gif"〉〈mi〉μ〈/mi〉〈/math〉rad. This collimation is provided by a stack of 14 tungsten slits, arranged with a relative rotation around the beam axis, so that the overlap will be a continuously adjustable aperture. To monitor the operation and alignment of the collimation, a set of detectors will provide a complete characterization of the gamma beam, including the measurement of the transverse spatial distribution. For this task a gamma beam profile imager based on a thin scintillator screen and a high-resolution CCD-camera was developed. In this work we briefly present the status of the collimation system and beam profile imager, which were designed, assembled and are currently under test at INFN-Ferrara laboratories.〈/p〉〈/div〉

Description: 〈p〉Publication date: 11 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 911〈/p〉 〈p〉Author(s): N. Buzarbaruah, S.R. Mohanty, E. Hotta〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The adaption of new generation portable neutron sources has been increasingly marked in a wide range of research fields compared to the large-scale neutron generators. In this context, we have successfully demonstrated some essential parameters required for the emission of 2.45 MeV DD fusion neutrons from a steady state portable linear neutron source based on inertial electrostatic confinement scheme. The parameters that control the production of neutrons are the working pressure of the fuel gas, applied voltage, measured current and cathode geometries. The neutrons emitted from the source are confirmed using neutron monitor, bubble dosimeters, nuclear track detectors, and He-3 proportional counter. Presently, the device produces neutrons up to the order of 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mo〉∼〈/mo〉〈/math〉 10〈sup〉6〈/sup〉 n/sec at discharge voltage ranging from -60 kV to -80 kV, and discharge current of 20 mA to 30 mA.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): Yu.A. Chesnokov, V.A. Maisheev〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The problem of creation of high energy neutrino beams on the basis of modern and future circular proton accelerators with the help of traditional technology seems to be expensive and difficult. Because of this, we propose the solution of this problem based on the usage of focusing bent single crystals. In the paper we demonstrate the possibilities of acceptance and focusing of a pion beam with the help of a crystal optical lens system. As an illustration of these features the calculated neutrino fluxes for energy of circulating proton beam equal to 6.5 TeV are presented.〈/p〉〈/div〉

Description: 〈p〉Publication date: 11 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 911〈/p〉 〈p〉Author(s): L. Werner, M. Trunk, R. Gernhäuser, R. Gilles, B. Märkisch, Zs. Révay〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The cold neutron guide of the Prompt Gamma Activation Analysis (PGAA) instrument (Revay et al. 2015) at the Heinz Maier-Leibnitz Zentrum (MLZ) provides an excellent opportunity for neutron depth profiling (NDP) due to its high collimated neutron flux. We present the concept, layout and first measurements with the new N4DP facility set-up at this beamline. A special focus is put on background analysis and instrument characterization. We present measurements of a NIST reference sample and of boron-containing float glasses which are used for neutron optical waveguides. We give an outlook concerning the ongoing development of position-resolved NDP using silicon microstrip detectors.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): Z. Scholz, M. Millett, M. Schell〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Surrogate radiation sources are used to test detection equipment and train security personnel in the detection and interdiction of special nuclear material (SNM). Some current surrogate sources do not accurately match SNM energy spectra, including for HEU. In this research, we propose and investigate novel source configurations for higher fidelity surrogate SNM sources using thermal neutron capture reactions that result in prompt gammas. The objective is to create a surrogate source that has a more representative spectrum, low cost, and requires minimal security, special handling, and safety precautions.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 6 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): Ping Yang, Weiping Ren, Xiangming Sun, Guangming Huang, Le Xiao, Chaosong Gao, Xing Huang, Wei Zhou, Yashu Li, Jianchao Liu, Bihui You, Li Zhang, Jun Liu, Ying Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Circular Electron Positron Collider (CEPC) is proposed as a Higgs factory for precision measurement of properties of the Higgs boson. The CEPC vertex detector requires low material budget, high spatial resolution, fast readout and low power consumption. Monolithic Active Pixel Sensor (MAPS), as one of the promising candidate technologies, has been studied within the R&D activities for the CEPC vertex detector. This proceeding introduces recent development of a MAPS prototype using the TowerJazz 180 nm CMOS Image Sensor process. Two different binary front-end circuits have been designed to explore an in-pixel front-end structure suitable for a compact pixel in combination with an in-matrix sparsified readout circuitry. To achieve high granularity together with fast readout speed, a new architecture of asynchronous data-driven matrix readout has been implemented. The prototype contains 128 rows and 64 columns featuring a small pixel pitch of 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mn〉25〈/mn〉〈mspace width="1em"〉〈/mspace〉〈mi mathvariant="normal"〉μ〈/mi〉〈mi mathvariant="normal"〉m〈/mi〉〈/math〉. The address of one hit pixel can be read out in 25 ns. This work presents the design of the prototype, which is currently under test.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): Seiichi Yamamoto, Hideo Nitta〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Gd〈sub〉3〈/sub〉(GaAl)〈sub〉5〈/sub〉O〈sub〉12〈/sub〉:Ce (GGAG) is a ceramic scintillator originally developed for X-ray CT, and it was also an excellent material for the development of an event-by-event-based radiation imaging detector when it was combined with a position sensitive photomultiplier (PSPMT). With the developed GGAG imaging detector, we found that the decay times for alpha particles and gamma photons were different. Also, we found that the decay times for alpha particles and beta particles were different. These characteristics are advantageous for developing an imaging detector for the simultaneous imaging of different types of radiation using pulse shape discrimination. Thus, we tested the separation of the images of the alpha particles and gamma photons using pulse shape discrimination. Also, we evaluated the separation of the alpha and beta particle images. In the pulse shape spectra, we could separate the peaks of Am-241 alpha particles and Cs-137 gamma photons with a peak-to-valley ratio (P/V) of 3.5. We obtained clearly separated images for Am-241 alpha particles and Cs-137 gamma photons using pulse shape discrimination. We could also separate the peaks of Am-241 alpha particles and Sr–Y-90 beta particles with a P/V of 1.5 in the pulse shape spectrum. We obtained separated images for Am-241 alpha particles and Sr–Y-90 beta particles using pulse shape discrimination. In addition, we could separate electrostatically collected natural alpha particles, Po-218 and Po-214, from the environmental beta particles and gamma photons using pulse shape discrimination. We conclude that the GGAG imaging detector is promising for simultaneous imaging and separating the images of different types of radiation using pulse shape discrimination.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 9 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): D. Bernard〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉No 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si64.gif"〉〈mi〉γ〈/mi〉〈/math〉-ray polarimeter sensitive above 1 MeV has ever flown space. 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si64.gif"〉〈mi〉γ〈/mi〉〈/math〉-ray polarimetry would be a new window on the radiative processes at work in cosmic sources, processes that produce linearly polarised emission, each of which with different polarisation fractions. The HARPO Collaboration has designed, built and characterised on beam a gas-TPC active target with which we have demonstrated for the first time the polarimetry of a linearly polarised MeV 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si64.gif"〉〈mi〉γ〈/mi〉〈/math〉-ray beam, from the analysis of the conversions to 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si65.gif"〉〈msup〉〈mrow〉〈mi〉e〈/mi〉〈/mrow〉〈mrow〉〈mo〉+〈/mo〉〈/mrow〉〈/msup〉〈msup〉〈mrow〉〈mi〉e〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈/mrow〉〈/msup〉〈/math〉 pairs.〈/p〉〈/div〉

Description: 〈p〉Publication date: 11 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 911〈/p〉 〈p〉Author(s): Songqing Tan, Rui Li, Chunlong Guo, Tao Shi, Yongqun Zhao, Xiaopeng Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper proposes a novel input power control strategy for high-power dynamic power supply for proton therapy. A buck chopper is staged in series between the input rectifier and the output chopper of the power supply to buffer the input power fluctuation, which can reduce the reactive power exchange between the power supply and power grid and reduce the power distribution requirements. The validity of this proposed control principle has been verified on a high-power dynamic dipole power supply for proton therapy.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 5 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): M. Mallamaci, B. Baibussinov, G. Busetto, D. Corti, A. De Angelis, F. Di Pierro, M. Doro, L. Lessio, M. Mariotti, R. Rando, E. Prandini, P. Vallania, C.F. Vigorito, for the CTA LST project〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A Silicon Photomultiplier (SiPM)-based photodetector is being built to demonstrate its feasibility for an alternative silicon-based camera design for the Large-Sized Telescope (LST) of the Cherenkov Telescope Array. It has been designed to match the size of the standard Photomultiplier Tube (PMT) cluster unit and to be compatible with mechanics, electronics and focal plane optics of the first LST camera. Here, we describe the overall SiPM cluster design along with the main differences with respect to the currently used PMT cluster unit. The fast electronics of the SiPM pixel and its layout are also presented. In order to derive the best working condition for the final unit, we measured the SiPM performances in terms of gain, photo-detection efficiency and cross-talk. One pixel, a unit of 14 SiPMs, has been built. We will discuss also some preliminary results regarding this device and we will highlight the future steps of this project.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 16 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): I. Mattei, G. Battistoni, M. De Simoni, Y. Dong, A. Embriaco, M. Fischetti, E. Gioscio, C. Mancini-Terracciano, M. Marafini, R. Mirabelli, S. Muraro, A. Sarti, A. Sciubba, E. Solfaroli Camillocci, G. Traini, S.M. Valle, V. Patera〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The use of C, He and O as beam particles in Particle Therapy (PT) treatments is getting more and more widespread as a consequence of the enhanced relative biological effectiveness and oxygen enhancement ratio of such projectiles with respect to protons. The advantages in the tumour control probability, related to the improved efficacy of ions, are calling for an online monitor of the dose release spatial distribution. Such technology is currently missing in PT treatments clinical routine. In this contribution the status of 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mi〉Z〈/mi〉〈mo〉〉〈/mo〉〈mn〉1〈/mn〉〈/math〉 ions PT treatments monitoring, exploiting the detection of either charged secondary particles or neutrons, is reviewed. While charged fragments can be used to provide an online feedback to the beam control system, by correlating their emission profile with the position of the Bragg peak, neutrons have to be monitored to improve the experimental description of the secondary radiation component that significantly contributes to an undesired and not negligible dose deposition far away from the tumor region, enhancing the risk of secondary malignancies development after the treatment. Two tracker detectors, employing scintillating fibers, are presented: the Dose Profiler designed for charged secondary fragments measurements and the MONDO tracker dedicated to the characterisation of the secondary fast and ultrafast neutron component, within the MONDO (MOnitor for Neutron Dose in hadrOntherapy) project.〈/p〉〈/div〉

Description: 〈p〉Publication date: 11 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 911〈/p〉 〈p〉Author(s): Huachang Liu, Jun Peng, Keyun Gong, Ahong Li, Bo Li, Qiang Chen, Xiaolei Wu, Mengxu Fan, Yun Wang, Peihua Qu, Shinian Fu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The China Spallation Neutron Source (CSNS) is an accelerator-based multidisciplinary user facility constructed in Dongguan, Guangdong, China. The injector of the CSNS accelerator consists of 4 conventional Alvarez DTL tanks, and it accelerates an H- beam from 3 MeV to 80 MeV. There is a series of accelerator physics and technology challenges in the DTL design and construction. The transverse focusing is arranged in a FFDD lattice utilizing a newly developed electromagnetic quadrupole magnets. The DTL cavity is copper-plated to enhance the electrical conductivity of the tank inner RF surface. There is not any space for steering magnet installing in the 36 m long DTL section, which leads to a rather high precision requirements for fabrication, installation and RF tuning. Benefited from the advanced fabrication technology and optimized tuning strategy, the CSNS DTL shows an excellent performance in the beam commissioning. The beam is successfully accelerated to 80 MeV with nearly 100% transmissions. The detailed physics and cavity design are described, construction and beam commissioning results are also shown.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): Y. Nagata, N. Kuroda, B. Kolbinger, M. Fleck, C. Malbrunot, V. Mäckel, C. Sauerzopf, M.C. Simon, M. Tajima, J. Zmeskal, H. Breuker, H. Higaki, Y. Kanai, Y. Matsuda, S. Ulmer, L. Venturelli, E. Widmann, Y. Yamazaki〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉An antihydrogen detector consisting of a thin BGO disk and a surrounding plastic scintillator hodoscope has been developed. We have characterized the two-dimensional positions sensitivity of the thin BGO disk and energy deposition into the BGO was calibrated using cosmic rays by comparing experimental data with Monte-Carlo simulations. The particle tracks were defined by connecting BGO hit positions and hits on the surrounding hodoscope scintillator bars. The event rate was investigated as a function of the angles between the tracks and the energy deposition in the BGO for simulated antiproton events, and for measured and simulated cosmic ray events. Identification of the antihydrogen Monte Carlo events was performed using the energy deposited in the BGO and the particle tracks. The cosmic ray background was limited to 12 mHz with a detection efficiency of 81%. The signal-to-noise ratio was improved from 0.22 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉s〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈mn〉1〈/mn〉〈mo〉∕〈/mo〉〈mn〉2〈/mn〉〈/mrow〉〈/msup〉〈/math〉 obtained with the detector in 2012 to 0.26 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉s〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈mn〉1〈/mn〉〈mo〉∕〈/mo〉〈mn〉2〈/mn〉〈/mrow〉〈/msup〉〈/math〉 in this work.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 9 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): J. Zorn, for the CTA GCT project〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Compact High-Energy Camera (CHEC) is a design option proposed for the small-sized telescopes (SSTs) of the Cherenkov Telescope Array (CTA), focusing on the gamma-ray detection at the upper end of the gamma-ray spectrum (from 1 TeV up to around 300 TeV). Thanks to the use of dual-mirror, Schwarzschild-Couder (SC) optics, CHEC can be – by design – very compact (0.5 m 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mo〉×〈/mo〉〈/math〉 0.5 m), light (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si15.gif"〉〈mo〉∼〈/mo〉〈/math〉50 kg), and low-cost (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si15.gif"〉〈mo〉∼〈/mo〉〈/math〉150€). Using electronics based on TARGET (TeV Array Read-out with GSa/s sampling and Event Trigger) application-specific integrated circuits (ASICs) and field programmable gate arrays (FPGAs) allows a flexible trigger scheme and continuous sampling at 1 GSa/s. Full waveforms for all 2048 pixels are read out without loss at over 600 Hz. Two full prototype cameras have been developed. The first, based on multi-anode photomultipliers (MAPMs) as photosensors, was successfully characterised in the laboratory and during on-telescope campaigns where it saw Cherenkov light from air showers, as the first CTA camera prototype and the first camera ever using SC optics. The second, featuring upgraded ASICs and Silicon photomultipliers (SiPMs), is under commissioning at the Max-Planck-Institut für Kernphysik in Heidelberg.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 5 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): S. Abovyan, V. Danielyan, M. Fras, O. Kortner, H. Kroha, R. Richter, Y. Zhao, A. Baschirotto, M. De Matteis, F. Resta〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In order to fully exploit the physics potential of the ATLAS experiment at the HL-LHC, the trigger rate of and maximum latency of the first-level trigger system will be increased to 1 MHz and 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mn〉10〈/mn〉〈mspace width="1em"〉〈/mspace〉〈mi mathvariant="normal"〉μ〈/mi〉〈mi mathvariant="normal"〉s〈/mi〉〈/math〉, respectively. In addition, a new first-level muon track trigger with high momentum resolution based on the ATLAS precision Muon Drift-Tube (MDT) chambers will be employed which requires triggerless readout. The TDC ASICs of the current front-end electronics of the MDT chambers are incompatible with these requirements. The front-end boards, each with a TDC chip and three 8-channel amplifier–shaper–discriminator (ASD) chips have to be replaced. Therefore, a new octal ASD2 ASIC has been developed in modern 130 nm IBM/Global Foundries CMOS technology. The chip also contains a Wilkinson ADC to perform both time-over-threshold and signal charge measurement. The ASD design has been fully qualified for the serial production of 80000 chips for ATLAS. The performance in terms of signal rise time and channel uniformity significantly surpasses the one of the previous chip while keeping the power consumption constant. In addition to the characterization with test pulses, several chips have been mounted on the front-end boards and tested in a muon beam at the Gamma Irradiation Facility GIF++ at CERN up to high counting rates where the superior drift time and spatial resolution becomes evident.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 913〈/p〉 〈p〉Author(s): J.P. Holzbauer, C. Contreras, Y. Pischalnikov, D. Sergatskov, W. Schappert〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉SRF cavity quality factors can be accurately measured using RF-power based techniques only when the cavity is very close to critically coupled. This limitation is from systematic errors driven by non-ideal RF components. When the cavity is not close to critically coupled, these systematic effects limit the accuracy of the measurements. The combination of the complex base-band envelopes of the cavity RF signals in combination with a trombone in the circuit allow the relative calibration of the RF signals to be extracted from the data and systematic effects to be characterized and suppressed. The improved calibration allows accurate measurements to be made over a much wider range of couplings. Demonstration of these techniques during testing of a single-spoke resonator with a coupling factor of near 7 will be presented, along with recommendations for application of these techniques.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): Mukhtar Ahmed Rana〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The influence of preservation period of CR-39 detectors, in refrigerator and in the laboratory atmosphere, on bulk etch rate is studied. The effect of etching solution usage time on the bulk etch rate is also investigated. Analyses and quantitative results in the said cases are presented. Finally, precision results on the use of CR-39 as a charged particle detector are presented in a systematic manner. These results are selected from our radiation detection and measurement experiments, ranged over last two decades. Selected results (unpublished and published) include CR-39 measurements of 5.9 MeV antiprotons, 6.12 MeV alpha particles and spontaneous fission fragments of 〈sup〉252〈/sup〉Cf. Our published results, presented here, are further analyzed and presented in comparison with new results and discussion. Experimental procedures of exposures, chemical etching, track measurements using the optical microscopy are described, keeping in view the new users and research students. Computer codes TRACK_Vision and SRIM were employed to provide a comparison with measurements of track parameters, where possible.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 8 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): H. Gómez〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Muon tomography, or muography, stands out as a non-invasive technique for the scanning of big objects internal structure. It relies on the measurement of the direction changes or absorption of atmospheric muons when crossing the studied object. For the first case, the trajectory reconstruction of muons upstream and downstream the object, provides information to generate its 3D density map. For bigger objects, a 2D map can be obtained by measuring the absorption for different incident directions. Proposed several decades ago, the performance achieved in particle detectors in the last years, specially in terms of stability, robustness and precision, has enlarged the possible applications of this technique.〈/p〉 〈p〉Bulk Micromegas represent a well-known technology suitable for the construction of muon telescopes based on these detectors. Thus autonomous and portable instruments have been conceived and constructed at 〈em〉Commissariat à l’Énergie Atomique et aux Énergies Alternatives〈/em〉 (CEA), being able to perform measurements 〈em〉in-situ〈/em〉, next to the studied objects. Furthermore, a Geant4-based simulation framework, capable to handle 3D models of the studied objects, is also being implemented to be used as support tool during the feasibility studies and for data analysis and results interpretation.〈/p〉 〈/div〉

Description: 〈p〉Publication date: Available online 12 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): B. Canion, J. Dreyer, O. Drury, D. Trombino, K. Nelson, B. Seilhan, S. Labov, K. Jarman, B. McDonald, M. Zalavadia, M. Myjak, D. Pfund, J. Forrester, G. Lawson〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉We investigate a new safeguards approach for verification of uranium processing operations via standoff measurement of UF〈sub〉6〈/sub〉 cylinder transports entering and leaving a facility. Current safeguards verification at facilities with UF〈sub〉6〈/sub〉 cylinders includes attended enrichment measurements of several randomly-selected cylinders using handheld instruments with inspection of all the cylinders typically only once a year. This approach requires significant inspector effort and can only be performed intermittently. Here we explore an unattended, multi-sensor enrichment measurement system that can operate continuously on cylinders in motion. Such an approach could be used to enhance continuity of knowledge by verifying that all shipments entering and leaving a facility are consistent with declared operations.〈/p〉 〈p〉The challenges in developing a standoff enrichment technique include limited statistical significance of the collected data, and interpreting the complex signatures from a shipment of UF〈sub〉6〈/sub〉 cylinders. These signatures vary with cylinder properties (e.g. the fuel cycle history, cylinder history, material distribution, material age, etc.) and measurement conditions (e.g. speed and distance of vehicle, detector response, cylinder orientation, attenuation from overpack and vehicle, etc.).〈/p〉 〈p〉In this paper, we demonstrate that we can extract useful enrichment signatures from standoff measurements of UF〈sub〉6〈/sub〉 cylinders entering and leaving a facility. Our initial analysis demonstrates a measurable difference in enrichment-related signatures from a cylinder in motion, measured with modest detection efficiency from several meters away. We also demonstrate that the inclusion of vehicle tracking increases the signal-to-noise ratio (SNR) of our radiation signatures, and decreases uncertainty of parameters needed for enrichment analysis, e.g. distance and velocity.〈/p〉 〈/div〉

Description: 〈p〉Publication date: Available online 6 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): G. Matarrese, P.A.P. Calò, F. Corsi, C. Marzocca, S. Petrignani〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉High-gain photomultiplier detectors are employed in an increasing number of applications in different fields to evaluate with great accuracy the occurrence time of light flashes composed by few or even single photons. Examples of these application fields are medical imaging, astroparticle and high energy physics, laser spectroscopy and LIDAR. To fulfill a good single photon timing accuracy, in the range of few hundreds of picoseconds, not only detectors with intrinsic excellent timing resolution (photomultiplier tubes, microchannel plated detectors, silicon photo multipliers, etc.) must be used, but the very first front-end amplifier (FEA) stage, used to read-out the detector, must also be carefully chosen and designed.〈/p〉 〈p〉We compare here three commonly used solutions for the FEA, from the point of view of the best achievable timing resolution: the charge sensitive amplifier (CSA), the voltage amplifier (VA) and the current buffer (CB). The results show that the CSA solution is limited in terms of frequency response by the usually large equivalent capacitance of the detector and that, surprisingly, the presence of the parasitic inductance 〈em〉L〈/em〉, due to interconnection detector-FEA, has a noise shaping effect which favourably affects the timing accuracy of the CB over the VA configuration. To support this study, simulations of simple implementations of the compared FEA solutions have been performed, under the same conditions.〈/p〉 〈p〉Moreover, with reference to a given detector and to a particular value of 〈em〉L〈/em〉, we show how the best timing accuracy of the CB is obtained by selecting an appropriate combination of input resistance and bandwidth of the FEA.〈/p〉 〈/div〉

Description: 〈p〉Publication date: Available online 5 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): I. Semeniouk, D. Bernard〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We present the C++ implementation of an event generator for linearly-polarized gamma-ray conversions to 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈mi〉γ〈/mi〉〈mo〉→〈/mo〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉e〈/mi〉〈/mrow〉〈mrow〉〈mo〉+〈/mo〉〈/mrow〉〈/msup〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉e〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈/mrow〉〈/msup〉〈/math〉 pairs. The generator uses the full 5D Bethe–Heitler probability density function for the generation of the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈mi〉γ〈/mi〉〈mo〉→〈/mo〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉e〈/mi〉〈/mrow〉〈mrow〉〈mo〉+〈/mo〉〈/mrow〉〈/msup〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉e〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈/mrow〉〈/msup〉〈/math〉 pair and for the recoil of the target nucleus. The same code is used for triplet generation. We present a verification of the model by comparing sample distributions with theoretical predictions.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 5 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): B. Juste, S. Morató, C. García, R. Miró, G. Verdú〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Different methods exist to verify bunkers design for radiation therapy medical facilities; analytical methods based on simplified equations and Monte Carlo methods. One of the main purposes of this work is to present the advantages of using Monte Carlo simulation to verify radiotherapy bunker shielding design. This methodology is more accurate and characterizes not only the fluence and dose three-dimensionally, but also the energy spectrum of particles generated by the LinAc. The other main purpose of the work is to analyze the importance of the generated photoneutrons when the LinAc emits high-energy photon beams (above 8 MeV), since numerous studies have found that these neutrons can expose the patient and clinical staff to non-negligible dose. The main novelty introduced by this work, is the creation of more realistic geometry simulation models to represent the radiotherapy facility by using CAD and meshes technologies which can be imported to MCNP6 Monte Carlo code. Results obtained using these bunker simulation models have been validated experimentally at the Hospital Universitari i Politècnic La Fe de Valencia facilities using two different neutron detectors; the neutron meter LB 6411 (designed between Berthold and Karlsruhe Research Center) and neutron detector model 42 - 41L (Ludlum, Prescila). Neutron dose results obtained with Monte Carlo and those measured experimentally fit correctly, validating this analysis methodology.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 9 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): L. Wiik-Fuchs, L. Diehl, R. Mori, M. Hauser, K. Jakobs, S. Kühn, U. Parzefall, A.A. Affolder, V. Fadeyev, C. García, C. Lacasta, D. Madaffari, U. Soldevila, Y. Unno〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The upgrade of the LHC to the High Luminosity LHC will challenge the silicon strip detector performance with high fluence and long operation time. Sensors have been designed and tests on charge collection and electrical performance have been carried out in order to evaluate their behaviour. Besides that, it is important to understand and predict the long-term evolution of the sensor properties. In this work, detailed studies on the annealing behaviour of ATLAS12 strip sensors designed by the ITK Strip Sensor Working Group and irradiated from 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈mn〉5〈/mn〉〈mo〉×〈/mo〉〈mn〉1〈/mn〉〈msup〉〈mrow〉〈mn〉0〈/mn〉〈/mrow〉〈mrow〉〈mn〉13〈/mn〉〈/mrow〉〈/msup〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉n〈/mi〉〈/mrow〉〈mrow〉〈mi mathvariant="normal"〉eq〈/mi〉〈/mrow〉〈/msub〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉cm〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈mn〉2〈/mn〉〈/mrow〉〈/msup〉〈/math〉 to 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si4.gif"〉〈mn〉2〈/mn〉〈mo〉×〈/mo〉〈mn〉1〈/mn〉〈msup〉〈mrow〉〈mn〉0〈/mn〉〈/mrow〉〈mrow〉〈mn〉15〈/mn〉〈/mrow〉〈/msup〉〈msub〉〈mrow〉〈mi mathvariant="normal"〉n〈/mi〉〈/mrow〉〈mrow〉〈mi mathvariant="normal"〉eq〈/mi〉〈/mrow〉〈/msub〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉cm〈/mi〉〈/mrow〉〈mrow〉〈mo〉−〈/mo〉〈mn〉2〈/mn〉〈/mrow〉〈/msup〉〈/math〉 are presented. Systematic charge collection and leakage current measurements have been carried out during the annealing process until break-down or the appearance of charge multiplication. The annealing was carried out, separating the sensors into two groups being either annealed at 23 °C or 60 °C. Sensors showing charge multiplication have been then kept at high voltage for a long time in order to monitor their stability. The difference in the annealing behaviour between the two temperatures has been analysed and compared to similar measurements on n-type sensors and with a theoretical model. From the impedance measurements for the samples irradiated to low fluences it was possible to extract the effective doping concentration. This was compared to similar measurements on n-type sensors and with a theoretical model.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 9 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): Carlos Granja, Karel Kudela, Jan Jakubek, Pavel Krist, David Chvatil, Jan Stursa〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We evaluate and characterize the directional response of the semiconductor pixel detector Timepix to charged particles and secondary cosmic rays. The detector granularity and per-pixel spectrometric response enable to perform directional sensitive tracking of energetic charged particles in wide field-of-view. In the highly integrated MiniPIX readout the detector serves as a miniaturized, low-power and easily deployable particle micro-tracker. Angular measurements require normalization for the acceptance angle and geometric factor which are described and taken into account. The methodology and evaluation of directional response are developed for light charged particles and atmospheric secondary cosmic rays. Tests and calibration of angular resolution were performed with electron and proton beams. Resulting angular distributions are expressed in terms of elevation and azimuth angles in 14 bins and 36 bins, respectively, over the full 2〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mi〉π〈/mi〉〈/math〉 acceptance range. For zenith angle 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si17.gif"〉〈mi〉β〈/mi〉〈/math〉 〉 28° the angular distribution is fitted by 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈mo〉∼〈/mo〉〈/math〉 cos 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si4.gif"〉〈msup〉〈mrow〉〈/mrow〉〈mrow〉〈mi mathvariant="normal"〉n〈/mi〉〈/mrow〉〈/msup〉〈/math〉 (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si17.gif"〉〈mi〉β〈/mi〉〈/math〉) with n = 2.0 ± 0.2 expected from secondary cosmic ray muon distribution.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 910〈/p〉 〈p〉Author(s): G. Mauri, M. Mariotti, F. Casinini, F. Sacchetti, C. Petrillo〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The application of Si sensors coupled to Gd converters as thermal neutron counters is assessed in a series of test experiments on the neutron beam, among which scattering from standard samples. The prototype 1d detector is a Si microstrip sensor directly coupled to natural Gd converter and equipped with standard front-end electronics. The raw scattering data, collected by interfacing the detector with the data acquisition system available at the neutron source, show advantages and limits of this technology when applied to neutron detection. To improve the performances of the Si-based detector by means of an optimized discrimination of the neutron signals from noise and background radiation, a pulse shape analysis method is proposed. The effectiveness of this method is then explored by experimental tests on the neutron beam of two more prototype detectors, namely a PIN diode coupled to   〈sup〉157〈/sup〉Gd〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si138.gif"〉〈msub〉〈mrow〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msub〉〈/math〉O〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si139.gif"〉〈msub〉〈mrow〉〈/mrow〉〈mrow〉〈mn〉3〈/mn〉〈/mrow〉〈/msub〉〈/math〉 converters, and a Silicon photo-multiplier (SiPM) coupled to neutron scintillators. This study is aimed to real time applications and single event storage of the neutron information in time of flight instrumentation.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 31 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): D.M. Kasparek, B.S. McDonald, A.J. Gilbert, R.S. Wittman〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The International Atomic Energy Agency (IAEA) is responsible for verifying the mass of elemental uranium in various forms (powders, pellets, scrap) as part of inspections at nuclear fuel fabrication facilities. Current methods require in-field dissolution chemistry, which is time consuming and imposes operational challenges. Pacific Northwest National Laboratory (PNNL) is developing a prototype spectral x-ray radiography (SpecX) nondestructive assay system for noninvasive material mass quantification of uranium-bearing powders. The SpecX system uses a custom material estimation algorithm, which requires a high-fidelity pixel-by-pixel detector response model for accurate quantification. We performed a detailed characterization and built a model of a High-Energy X-ray Imaging Technology (HEXITEC) CdTe pixelated spectral detector. Here we present the detector characterization which led to that model, including a determination of the pixel-wise energy calibration, the detection efficiency, the detector uniformity, the detector stability, and a comparison of methods to remove charge-shared events.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 30 October 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): F. Pompili, B. Esposito, D. Marocco, S. Podda, M. Riva, S. Baccaro, A. Cemmi, I. Di Sarcina, L. Quintieri, D. Bocian, K. Drozdowicz, M. Curylo, J. Dankowski, J. Kotula, W. Maciocha, T. Nowak, J. Swierblewsk, L. Vermeeren, W. Leysen〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Radial Neutron Camera (RNC) of ITER (International Thermonuclear Experimental Reactor) is a multichannel detection system designed to measure the uncollided neutron flux from the fusion plasma, providing information on the neutron emissivity profiles and source strength. Fission chambers and diamond detectors are candidate detectors for the RNC In-port subsystem. This is a high radiation environment (up to 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mo〉∼〈/mo〉〈/math〉5 MGy gamma dose and 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mo〉∼〈/mo〉〈/math〉〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈mn〉2〈/mn〉〈mo〉×〈/mo〉〈mn〉10〈/mn〉〈/math〉〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si4.gif"〉〈msup〉〈mrow〉〈/mrow〉〈mrow〉〈mn〉16〈/mn〉〈/mrow〉〈/msup〉〈/math〉 n/cm〈sup〉2〈/sup〉 neutron fluence) where about 500 baking cycles up to 240 °C are foreseen over the whole ITER lifetime. In order to assess the feasibility of using diamond detectors in such harsh conditions, and to study the best technological solutions, we are currently performing a set of tests to understand the behavior of diamond detectors under radiation and thermal stresses: (1) thermal stress tests at constant temperature of 240 °C and thermal cycling between 100 °C and 240 °C; (2) gamma-hardness test up to a total dose of 4.7 MGy; (3) neutron-hardness test (limited to 2 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si5.gif"〉〈mo〉×〈/mo〉〈mn〉10〈/mn〉〈/math〉〈sup〉14〈/sup〉 n/cm〈sup〉2〈/sup〉 in this work).〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 208〈/p〉 〈p〉Author(s): Xing Peng, Xian Wei, Tieyu Chen〈/p〉

Description: 〈p〉Publication date: 5 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 208〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 210〈/p〉 〈p〉Author(s): Peng Qu, Xiaohua Ma, Wansong Chen, Dandan Zhu, Huifei Bai, Xiuhua Wei, Shu Chen, Maotian Xu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A new ratiometric fluorescent probe (〈strong〉1〈/strong〉) was developed for the detection of hydrazine. The probe was obtained by incorporating the recognition moiety of acetyl group onto a coumarin fluorophore. Probe 〈strong〉1〈/strong〉 displayed a distinct cyan emission in a 100% aqueous phosphate buffer solution. In the presence of hydrazine, probe 〈strong〉1〈/strong〉 undergoes a hydrazinolysis process to release the coumarin fluorophore, which exhibited significant hypsochromic shifts in both absorption and emission spectra, and thus achieving a ratiometric response. This ratiometric probe is highly selective and sensitive towards hydrazine detection. The limit of detection (LOD) was calculated to be 34 nM. Moreover, cellular toxicity and imaging experiments suggested that probe 〈strong〉1〈/strong〉 is can be used to monitor hydrazine in live cells.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518309983-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 916〈/p〉 〈p〉Author(s): J. Benlliure, D. Cortina-Gil, J.J. Llerena, C. Ruiz〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Laser Laboratory for Acceleration and Applications (L2A2) is a new facility, recently built at the University of Santiago de Compostela in Spain, to investigate laser–plasma acceleration technologies. This facility is equipped with a 50 TW laser system and a radio-protected area where different laser–plasma induced radiation sources are being implemented. In this paper we use Monte Carlo radiation transport simulations based on the code Fluka to validate the radiation shielding installed at L2A2 for proton, neutron and electron sources generated with the present laser system, but also for future possible upgrades increasing the laser power to 100 and 200 TW. Particular attention is paid to the determination of the radiation source term describing the acceleration of electrons, protons and neutrons using over-dense and under-dense plasmas.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 916〈/p〉 〈p〉Author(s): Zhifu Liu, J.A. Peters, Joon-Il Kim, Sanjib Das, Kyle M. McCall, Bruce W. Wessels, Yihui He, Wenwen Lin, Mercouri G. Kanatzidis〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We report on the measurement of frequency dependent noise spectra of photoconductive ternary compounds Cs〈sub〉3〈/sub〉Sb〈sub〉2〈/sub〉I〈sub〉9〈/sub〉, Rb〈sub〉3〈/sub〉Sb〈sub〉2〈/sub〉I〈sub〉9〈/sub〉, Hg〈sub〉3〈/sub〉Se〈sub〉2〈/sub〉I〈sub〉2〈/sub〉, and TlSn〈sub〉2〈/sub〉I〈sub〉5〈/sub〉 for hard radiation detectors. The major sources of noise in these detectors are attributed to pickup noise, white noise, and frequency related 1/〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mi〉f〈/mi〉〈/math〉 noise. At low frequencies, the noise spectral density function exhibited 1/〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si2.gif"〉〈msup〉〈mrow〉〈mi〉f〈/mi〉〈/mrow〉〈mrow〉〈mi mathvariant="normal"〉α〈/mi〉〈/mrow〉〈/msup〉〈/math〉 behavior where 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈mi〉α〈/mi〉〈/math〉 is less than or equal to one. For those samples with 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈mi〉α〈/mi〉〈/math〉 equal to one, radiation detection performances of the detectors, in terms of spectral measurements, have been reported in previous publications. The origin of 1/f noise of those samples is attributed to carrier fluctuations associated with deep centers/trapped holes. For those samples with 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si3.gif"〉〈mi〉α〈/mi〉〈/math〉 less than one, the origin of the deviation from a linear 1/f dependence is unknown and currently under investigation. However, this deviation is correlated with higher background white noise and lowered detector performance, and thus indicates that the material needs to be further optimized. Noise measurements are a useful indicator for screening prospective materials and samples for detectors.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 14 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): Frank Simon〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Following first large-scale applications in highly granular calorimeters and in neutrino detectors, Silicon Photomultipliers have seen a wide adoption in accelerator-based particle and nuclear physics experiments. Today, they are used for a wide range of different particle detector types, ranging from calorimeters and trackers to particle identification and veto detectors, large volume detectors for neutrino physics and timing systems. This article reviews the current state and expected evolution of these applications, highlighting strengths and limitation of SiPMs and the corresponding design choices in the respective contexts. General trends and adopted technical solutions in the applications are discussed.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 12 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): A. Brossard, on behalf of the NEWS-G collaboration〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The New Experiments With Spheres-Gas (NEWS-G) collaboration uses spherical proportional counters (SPCs) filled with light noble gases for rare event detection. SPCs are a novel technology that have many appealing features for particle detection including sub-keV thresholds, single electron sensitivity, excellent energy resolution and flexibility in gas choice. In this paper, studies conducted at Queen’s University, focusing on the understanding, monitoring and improvement of the detector response will be presented. The detector consists of a 30 cm diameter sphere with a 2 mm anode at the center. With this set-up, we perform precision measurements with a UV laser and radioactive sources that encompass a wide range of fundamental characteristics of the detector.〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 210〈/p〉 〈p〉Author(s): Na-Na Li, Yu-Qing Ma, Xue-Jiao Sun, Ming-Qiang Li, Shuang Zeng, Zhi-Yong Xing, Jin-Long Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A simple naphthalene derivative, 6-hydroxy-2-naphthohydrazide (〈strong〉NAH〈/strong〉), was designed and synthesized through two facile steps reactions with the 6-hydroxy-2-naphthoic acid (NCA) as the starting material. In neat H〈sub〉2〈/sub〉O (10% 0.01 M HEPES buffer, v/v, pH = 7.4), probe 〈strong〉NAH〈/strong〉 showed a highly selective and sensitive response towards Fe〈sup〉3+〈/sup〉 via perceptible color change and displayed “turn-on” dual-emission fluorescence response for Cu〈sup〉2+〈/sup〉. The binding stoichiometry ratio of 〈strong〉NAH〈/strong〉/Cu〈sup〉2+〈/sup〉 and 〈strong〉NAH〈/strong〉/Fe〈sup〉3+〈/sup〉 were all confirmed as 1:1 by the method of fluorescence job's plot and UV–Vis job's plot, respectively. Probe 〈strong〉NAH〈/strong〉 can be used over a wide pH range for the determination of Fe〈sup〉3+〈/sup〉 (2.0–10.0) and Cu〈sup〉2+〈/sup〉 (6.0–10.0) without interference from other co-existing metal ions. A possible detection mechanism was the hydrolysis of 〈strong〉NAH〈/strong〉 upon the addition of Fe〈sup〉3+〈/sup〉 or Cu〈sup〉2+〈/sup〉, thereby leading to the formation of 6-hydroxy-naphthalene-2-carboxylic acid (〈strong〉NCA〈/strong〉) which was further confirmed by the various spectroscopic techniques including FT-IR, 〈sup〉1〈/sup〉H NMR titration and HRMS. Moreover, 〈strong〉NAH〈/strong〉 was successfully applied to the detection of Cu〈sup〉2+〈/sup〉 and Fe〈sup〉3+〈/sup〉 in tap water, ultrapure water and BSA.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S138614251831028X-ga1.jpg" width="333" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 12 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): T.Z. Kowalski〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The gas gain has been measured for a low and high count rate by means of the current method for cylindrical proportional counter of radius b = 12.5 mm with an axially placed anode of radius a = 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mn〉50〈/mn〉〈mspace width="1em"〉〈/mspace〉〈mi mathvariant="normal"〉μ〈/mi〉〈mi mathvariant="normal"〉m〈/mi〉〈/math〉, respectively for the mixture pressure of 1059,6 hPa.〈/p〉〈/div〉

Description: 〈p〉Publication date: 11 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 920〈/p〉 〈p〉Author(s): Chengjun Tan, Chuanxiang Tang, Wenhui Huang, Qingxiu Jin, Yingchao Du, Qun Luo, Peidong Wu, Donghai Liu, Luming Zhang, Cong Xu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Distributed X-ray sources provide a solid foundation for the invention of new-generation computed tomography (CT). This study proposes a novel multi-focal spot electron gun scheme for distributed X-ray sources. The source in this study uses a dispenser cathode as the electron emitter, a mesh grid to control emission current, and two electrostatic lenses for beam shaping, focusing, and deflecting. Novel focusing and deflecting electrodes were designed to increase the number of focal spots in the distributed source. It consists of two identical half-rectangle opening electrodes by adjusting the potential of the two electrodes to control the trajectory of the electron beam and then obtain multi-focal spots on the anode target. The number of X-ray sources in the distributed source is limited by the amount of cathodes. The multi-focal spot electron gun can break this limitation and provide more possibilities and options for distributed X-ray sources and stationary CT. Experimental results reflect the excellent repeatability of the multi-spot electron gun. The dynamic effective focal spot sizes of the deflected (deflected amplitude, 10.5mm) and non-deflected electron beams at full with half max (FWHM) are 1.30mm〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mo〉×〈/mo〉〈/math〉0.60mm and 1.15mm〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mo〉×〈/mo〉〈/math〉0.55mm, respectively (anode voltage, 160kV; beam current, 30 mA).〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 13 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): Y. Liang, X. Wen, J.E. Baciak, A. Enqvist〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉For the first time, the neutron and gamma-ray time-dependent cross-correlation distributions from spontaneous fission and ( 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mi〉α〈/mi〉〈/math〉, n) neutron sources are measured with the 〈sup〉4〈/sup〉He fast neutron detectors. The pulse shape discrimination technique based on charge comparison is utilized to discriminate between neutrons and gamma-rays in the identification of the four possible correlated pairs: ( 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si54.gif"〉〈mi〉γ〈/mi〉〈/math〉, 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si54.gif"〉〈mi〉γ〈/mi〉〈/math〉), (n, n), (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si54.gif"〉〈mi〉γ〈/mi〉〈/math〉, n), and (n, n). Both total and individual cross-correlation functions are obtained, and their shapes can be easily distinguished among different neutron sources. The (n, n) and ( 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si54.gif"〉〈mi〉γ〈/mi〉〈/math〉, n) correlations are selectively analyzed and the peak position of the (n, n) and ( 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si54.gif"〉〈mi〉γ〈/mi〉〈/math〉, n) pairs shows a linear correlation with source-detector distance. The measurements illustrate the feasibility of using 〈sup〉4〈/sup〉He detectors to identify nuclear materials and their geometrical configurations, as well as other applications in nuclear nonproliferation and safeguards. In particular, the (n, n) correlated data can be very clearly assayed even in presence of significant gamma fields without the use of shielding.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 12 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): G. Ambrosi, M. Ambrosio, C. Aramo, B. Bertucci, E. Bissaldi, M. Bitossi, A. Boiano, C. Bonavolontá, M. Caprai, L. Consiglio, L. Di Venere, E. Fiandrini, N. Giglietto, F. Giordano, M. Ionica, F. Licciulli, S. Loporchio, V. Masone, R. Paoletti, A. Rugliancich〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Recent developments on Silicon Photomultipliers (SiPMs) have shown that they are particularly adequate to detect fast signal due to low-intensity light. Fondazione Bruno Kessler (FBK) has optimized these sensors for the Near-Ultraviolet Cherenkov light emitted by high energy gamma-ray showers in the atmosphere. The FBK high density SiPMs (NUV-HD) have been extensively characterized in the laboratories of the Italian Institute of Nuclear Physics (INFN) in view of equipping the focal plane camera of the Schwarzschild-Couder Telescope prototype (pSCT) in the framework of the Cherenkov Telescope Array (CTA). Here we report the performances of the 6 × 6 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉mm〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msup〉〈/math〉 SiPMs based on 40 × 40 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si2.gif"〉〈msup〉〈mrow〉〈mi mathvariant="normal"〉μm〈/mi〉〈/mrow〉〈mrow〉〈mn〉2〈/mn〉〈/mrow〉〈/msup〉〈/math〉 cells, in terms of gain and signal-to-noise ratio. We compare the results obtained on devices from the latest generation and grown on different substrates in order to choose the most suitable sensor for the pSCT camera.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 12 November 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): T. Maruhashi, H. Morita, M. Arimoto, J. Kataoka, K. Fujieda, H. Nitta, H. Ikeda, H. Kiji〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉X-ray computed tomography (CT) has been widely used in the diagnostic imaging of the interior of the human body. However, the radiation dose of conventional CT typically amounts to 10 mSv. Under such environments, X-ray photons are severely piled-up; therefore, conventional CT acquires energy integrated images, and artifacts are formed by beam hardening. In contrast, a photon counting CT (PC-CT) system is anticipated to construct a low-dose and multi-color CT system. Recently, we proposed a novel PC-CT system using a multipixel photon counter (MPPC) coupled with a high-speed scintillator, which is cost effective and easy to assemble compared to other methods using CdZnTe device. In this paper, we report the results using an advanced CT system consisting of a 16-channel MPPC and scintillator array coupled with a newly developed large-scale integrated circuit (LSI) having an ultrafast signal processing capability. We present the performance of the photon-counting CT capability, such as the contrast of the obtained CT images compared with that of the current-mode CT, and we found that substantial reduction in radiation dose by an order of magnitude. In addition, we report the results of three-dimensional multicolor imaging to identify phantom materials.〈/p〉〈/div〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 212〈/p〉 〈p〉Author(s): Chuang Liu, Keyin Liu, Minggang Tian, Weiying Lin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hydrazine and its derivatives are one of the most important raw chemical materials that have extensive utilization in many areas. It is also widely applied as pharmaceutical derivatives, such as the antipsychotic drug, anti-infective drug, and antitumor drug. However, hydrazine is a highly toxic reagent which can bring severe damage to human and animals. Herein, we have reported a new benzothiazole substituted naphthalene based probe for hydrazine with huge fluorescence change ratio. The fluorescence change ratio at F〈sub〉390〈/sub〉/F〈sub〉509〈/sub〉 is up to 200-fold in the presence of hydrazine in 60 min. The probe exhibited negligible cytotoxicity toward HeLa cells and was applied for hydrazine detection successfully in HeLa cells.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310886-ga1.jpg" width="447" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Qingming Wang, Lei Jin, Wenling Wang, Lihui Dai, Xiaoxue Tan, Cong Zhao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This work, two turn-on fluorescent probes (3-acetyl-2H-chromen-2-one (〈strong〉ACO〈/strong〉) & (1E)-1-(1-(2-oxo-2H-chromen-3-yl)ethylidene)thiosemicarbazide (〈strong〉CETC〈/strong〉)) based on coumarin have been designed and synthesized, which could selectively and sensitively recognize ClO〈sup〉−〈/sup〉 with fast response time. 〈strong〉ACO〈/strong〉 & 〈strong〉CETC〈/strong〉 were almost non fluorescent possibly due to both the lacton form of coumarin and unbridged C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉N bonds which can undergo a nonradiative decay process in the excited state. Upon the addition of ClO〈sup〉−〈/sup〉, 〈strong〉ACO〈/strong〉 & 〈strong〉CETC〈/strong〉 were oxidized to ring - opened by cleavage the C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O and C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉N and the fluorescence intensity were increased considerably. Fluorescence titration experiments showed that the detection limit 〈strong〉ACO〈/strong〉 & 〈strong〉CETC〈/strong〉 is as low as 22 nm and 51 nm respectively. In particular, some relevant reactive species, including 〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/rad"〉OH, 〈sup〉1〈/sup〉O〈sub〉2〈/sub〉, H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉, KO〈sub〉2〈/sub〉, some anions and cations cannot be interference with the test. In live cell experiments, 〈strong〉ACO〈/strong〉 & 〈strong〉CETC〈/strong〉 were successfully applied to image exogenous ClO〈sup〉−〈/sup〉 in HepG2 cells. Therefore, 〈strong〉ACO〈/strong〉 & 〈strong〉CETC〈/strong〉 not only could image ClO〈sup〉−〈/sup〉 in living cells but also proved that C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O and C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉N can be cleavage by ClO〈sup〉−〈/sup〉.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉Two new coumarin-based fluorescent probes were synthesized and successfully achieved for the efficient detection of ClO〈sup〉−〈/sup〉 as turn - on fluorescence chemosensors in Tris - HCl buffer/DMSO (〈em〉v〈/em〉:〈em〉v〈/em〉 = 9:1, 20 mM, 〈em〉pH〈/em〉 = 7.0) with the detection of limit (LOD) as low as 22 nM and 51 nM, respectively.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310825-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Anees A. Ansari, Naushad Ahmad, Joselito P. Labis, Ahmed Mohamed El-Toni, Aslam Khan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Tb-doped Y〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 microspheres (MSs) were prepared via a homogeneous thermal degradation process at a low temperature and then coated with a nanosilica shell (Y〈sub〉2〈/sub〉O〈sub〉3〈/sub〉:Tb@SiO〈sub〉2〈/sub〉) using a sol-gel process. The core MSs were highly crystalline and spherical with a porous surface, single cubic phase, and particle size of 100–250 nm. Transmission electron microscopy (TEM) images clearly showed the spherical shape of the as-prepared core MSs, which were fully covered with a thick and mesoporous nanosilica shell. Fourier transform infrared (FTIR) spectra displayed the well-resolved infrared absorption peaks of silica (Si〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O, Si〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉O〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉Si, etc.), confirming the presence of the silica surface coating. The core MSs retained their spherical shape even after heat treatment and subsequent silica surface coating. It was observed that the core/shell MSs are easily dispersible in aqueous media and form a semi-transparent colloidal solution. Ultraviolet/visible and zeta potential studies were tested to prove the changes in the surface chemistry of the as-designed core/shell MSs and compare with their core counterpart. The growth of the amorphous silica shell not only increased the particle size but also enhanced remarkably the solubility and colloidal stability of the MSs in aqueous media. The strongest emission lines originating from the characteristic intra-shell 4f-4f electronic transitions of Tb ions were quenched after silica layer deposition, but the MSs still showed strong green (〈sup〉5〈/sup〉D〈sub〉4〈/sub〉 → 〈sup〉7〈/sup〉F〈sub〉5〈/sub〉 at 530–560 nm as most dominant) emission efficiency, which indicates great potential in fluorescent bio-probes. The emission intensity is discussed in relation to the quenching mechanism induced by surface silanol (Si-OH) groups, particle size, and surface charge.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310771-ga1.jpg" width="267" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 7 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): Tommaso Chiarusi, On behalf of the ANTARES and KM3NeT Collaborations〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉ANTARES, the underwater neutrino telescope in the Northern Hemisphere, has been continuously operating since 2007 in the Mediterranean Sea. The transparency of the water allows for a very good angular resolution in the reconstruction of interactions from neutrinos of all flavors. This results in unprecedented sensitivity for neutrino source searches in the Southern Sky at TeV energies, so that valuable constraints can be set on the origin of the cosmic neutrino flux discovered by the IceCube detector. Building on the successful experience of ANTARES the next generation KM3NeT neutrino telescope is now under construction in the Mediterranean Sea to significantly boost the sensitivity. Two detectors with the same technology but different granularity are under construction at two sites and will focus on high energy cosmic neutrinos (ARCA with Gton instrumented volume, offshore Capo Passero, Italy) and on atmospheric neutrinos at low energies down to a few GeV to address atmospheric neutrino oscillations (ORCA with Mtons instrumented volume, offshore Toulon, France). The basic KM3NeT detection element, the Digital Optical Module (DOM), houses 31 three-inch PMTs inside a 17 inch glass sphere. This multi-PMT concept allows for an accurate measurement of the light intensity (photon counting) and offers directional information with an almost isotropic field of view, at a reduced cost. This contribution will provide an overview on the newest results from ANTARES and an outlook towards the construction plan and exciting science potential of KM3NeT.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 919〈/p〉 〈p〉Author(s): Min Li, S.P. Li, W.L. Li, Peng Li, X.C. Kang, Y.C. Chen, R.S. Mao, T.C. Zhao, Z.G. Xu, Y.J. Yuan, J.M. Dong, Z.L. Zhao, Y.C. Feng, Y.G. Nie, W.N. Ma, Y.M. Wang, Yan Yin〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Heavy Ion Medical Machine (HIMM) is a compact synchrotron based facility built by the Institute of Modern Physics (IMP) in China. This facility delivers carbon ion beams with kinetic energies up to 400 MeV/u for clinical applications. The beam diagnostics system for HIMM is based on 18 different types of monitors and is used to measure all relevant beam parameters from the ion source to the irradiation therapy terminals which are critical for the commissioning of the accelerator as well as during the regular operation to ensure high up-time of the machine. The control system for all the monitors is designed, developed and implemented globally based on a 3-tier architecture with the aim to achieve a clear separation between front-end devices and their controllers. This paper presents the architecture, the design principle and the implementation of this control system. The beam parameters measured based on the detectors〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈msup〉〈mrow〉〈/mrow〉〈mrow〉〈mo〉′〈/mo〉〈/mrow〉〈/msup〉〈/math〉 motion control and data acquisition control system are analyzed in detail. Furthermore, this beam diagnostics control system (BDCS) will be transplanted to the next heavy ion medical machine in Lanzhou city on account of the successful application in Wuwei city, the precise beam parameters measurement, and long term operation with high stability and reliability.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 916〈/p〉 〈p〉Author(s): Matteo Morrocchi, Esther Ciarrocchi, Andrey Alexandrov, Behcet Alpat, Giovanni Ambrosi, Stefano Argirò, Raul Arteche Diaz, Nazar Bartosik, Giuseppe Battistoni, Nicola Belcari, Matteo Bertazzoni, Silvia Biondi, Graziano Bruni, Niccolò Camarlinghi, Pietro Carra, Piergiorgio Cerello, Alberto Clozza, Sofia Colombi, Giovanni De Lellis, Alberto Del Guerra〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This paper describes the development and characterization of a 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si9.gif"〉〈mi〉Δ〈/mi〉〈/math〉E-TOF detector composed of a plastic scintillator bar coupled at both ends to silicon photomultipliers. This detector is a prototype of a larger version which will be used in the FOOT (FragmentatiOn Of Target) experiment to identify the fragments produced by ion beams accelerated onto a hydrogen-enriched target. The final 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si9.gif"〉〈mi〉Δ〈/mi〉〈/math〉E-TOF detector will be composed of two layers of plastic scintillator bars with orthogonal orientation and will measure, for each crossing fragment, the energy deposited in the plastic scintillator (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si9.gif"〉〈mi〉Δ〈/mi〉〈/math〉E), the time of flight (TOF), and the coordinates of the interaction position in the scintillator. To meet the FOOT experimental requirements, the detector should have energy resolution of a few percents and time resolution of 70 ps, and it should allow to discriminate multiple fragments belonging to the same event. To evaluate the achievable performances, the detector prototype was irradiated with protons of kinetic energy in the 70–230 MeV range and interacting at several positions along the bar. The measured energy resolution 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si4.gif"〉〈msub〉〈mrow〉〈mi〉σ〈/mi〉〈/mrow〉〈mrow〉〈mi〉Δ〈/mi〉〈mi〉E〈/mi〉〈/mrow〉〈/msub〉〈mo〉∕〈/mo〉〈mi〉Δ〈/mi〉〈mi〉E〈/mi〉〈/math〉 was 6–14%, after subtracting the fluctuations of the deposited energy. A time resolution 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si5.gif"〉〈mi〉σ〈/mi〉〈/math〉 between 120 and 180 ps was obtained with respect to a trigger detector. A spatial resolution 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si5.gif"〉〈mi〉σ〈/mi〉〈/math〉 of 1.9 cm was obtained for protons interacting at the center of the bar.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 5 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): Yu.A. Melikyan, on behalf of ALICE collaboration〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The performance of the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si1.gif"〉〈mn〉25〈/mn〉〈mspace width="1em"〉〈/mspace〉〈mi mathvariant="normal"〉μ〈/mi〉〈mi mathvariant="normal"〉m〈/mi〉〈/math〉-pore Planacon MCP-PMT is discussed here and the device is evaluated for the use as the main photosensor of the Cherenkov arrays of the Fast Interaction Trigger (FIT) detector for the upgrade of the ALICE apparatus at the CERN LHC. During the LHC Run 3 and 4 FIT has to operate in strong magnetic fields and in large particle fluxes without significant ageing effects. The expected dynamic range for central modules of Cherenkov arrays of FIT is from 1 to 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si13.gif"〉〈mo〉∼〈/mo〉〈/math〉1000 MIPs. The required single-MIP time resolution is below 50 ps and the expected average repetition rate is 50 kHz. To fulfil these requests, the Planacon XP85012/A1-Q MCP-PMT has been customized into the XP85002/FIT-Q version. With the modified Planacon we were able to achieve a time resolution as low as 13 ps and ensure good timing of the device under the required dynamic range. A description of the implemented MCP-PMT modifications is presented here together with the outcome of the in-beam test of the assembled Cherenkov module and dedicated ageing- and magnetic field tests.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 4 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): Akihisa Ishikawa, Atsushi Yamazaki, Kenichi Watanabe, Sachiko Yoshihashi, Akira Uritani, Kentaro Fukuda, Akifumi Koike, Ryo Ogawara, Mitsuru Suda, Tsuyoshi Hamano〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We developed optical fiber-based neutron detectors that use small pieces of 〈sup〉6〈/sup〉Li-based scintillators, namely, Eu:LiCaAlF〈sub〉6〈/sub〉 crystals and LiF/Eu:CaF〈sub〉2〈/sub〉 eutectics. Considering that these elements have high light yields (more than 10,000 photons/neutron), they can produce pulse height spectra with clear peaks even when using optical fiber light guides. To adjust the neutron sensitivity, we controlled the amount of 〈sup〉6〈/sup〉Li in the scintillator. We fabricated three different detectors using Eu:LiCaAlF〈sub〉6〈/sub〉 and LiF/Eu:CaF〈sub〉2〈/sub〉 with various amounts of 〈sup〉6〈/sup〉Li and then evaluated the neutron sensitivity of each detector. This approach confirmed that there was a linear relationship between the neutron sensitivity and amount of 〈sup〉6〈/sup〉Li, thus implying that the 〈sup〉6〈/sup〉Li mass measured by a high-precision balance could be a good metric of neutron sensitivity. We also checked the linearity of the output of the detector at relatively high neutron fluxes by using an accelerator-based neutron source. Although the detectors showed saturation behavior at high count rate, we were able to cover a relatively wide dynamic range by combining multiple detectors using different amounts of 〈sup〉6〈/sup〉Li. After correcting for the pulse height distortion and count loss due to pile-up events, we were able to confirm the linearity of the detectors up to a count rates of 100 kcps.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Hongwei Ren, Xue Wang, Shaohan Lian, You Zhang, Erhong Duan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Deep eutectic solvents (DES) are generally composed of two or three cheap and safe components that are associated with each other via hydrogen bonds. The formation Caprolactam (CPL)-tetraalkyl ammonium halide (TAAX) DES and its hydrate were investigated using React IR. TAAX was introduced to CPL in the molten state at 353.15 K, the intermolecular H-N-C=O⋯H-N-C=O hydrogen bonds (CPL dimer) transfer to X〈sup〉−〈/sup〉⋯H-N-C=O (CPL-TAAX DES). When water was added to CPL-TAAX DES, intermolecular X〈sup〉−〈/sup〉⋯H-N-C=O⋯H-O-H hydrogen bonds appeared, and CPL-TAAX DES hydrate was formed. However, if the ratio of water exceeded the moral fraction of 0.61, CPL-TAAX DES hydrate turned into a CPL-TAAX aqueous solution. The C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O (1660 cm〈sup〉−1〈/sup〉) bonds were linearly correlated with hydrogen bonds number and TBAB amount in CPL-TBAB DES. When the molar fraction of CPL-TBAB DES was 0.39 to 0.78, the C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O peak redshift has a better linear correlation with water. Halide anions and the alkyl chain length of TAAX have little influence on the redshifts and peak intensity of the C〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/dbnd"〉O peak.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310679-ga1.jpg" width="344" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Abdel Majid A. Adam, Hala H. Eldaroti, Mohamed S. Hegab, Moamen S. Refat, Jehan Y. Al-Humaidi, Hosam A. Saad〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In our previous work, we highlighted the thermodynamic and spectroscopic characteristics of the 1:1 charge transfer (CT) complexation of TCNE acceptor with various medically important drugs. Continuing that work, we further examine drugs that react with the TCNE acceptor via a 1:2 interaction. The examined drugs are atenolol, quinidine, cimetidine, reserpine, and levofloxacin. We aimed through this study to: 〈em〉i〈/em〉) make the spectrophotometric and thermodynamic data of the examined drugs, both initially and when reacted via a 1:2 M ratio with the TCNE acceptor, available to use in the determination or detection of these drugs in pharmaceuticals and other environments; and 〈em〉ii〈/em〉) compare the mode of interactions and the spectrophotometric and thermodynamic properties between drugs that react via a 1:1 or 1:2 ratio with the TCNE acceptor. To achieve these aims, the five examined drugs were reacted with TCNE in acetonitrile (MeCN) solvent at room temperature. Several thermodynamic and spectroscopic data were experimentally estimated using the van't Hoff and the Benesi–Hildebrand equations and discussed.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉Electronic absorption spectrum of the CT product that formed form the reaction of drug Qui with TCNE acceptor in MeCN solvent.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310709-ga1.jpg" width="455" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 3 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): Fabio Acerbi, Stefan Gundacker〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The silicon-photomultiplier (SiPM) is becoming the device of choice for different applications, for example in fast timing like in time of flight positron emission tomography (TOF-PET) and in high energy physics (HEP). It is also becoming a choice in many single-photon or few-photon based applications, like for spectroscopy, quantum experiments and distance measurements (LIDAR). In order to fully benefit from the good performance of the SiPM, in particular its sensitivity, the dynamic range and its intrinsically fast timing properties it is necessary to understand, quantitatively describe and simulate the various parameters concerned. These analyses consider the structure and the electrical model of a single photon avalanche diode (SPAD), i.e. the SiPM microcell, and the integration in an array, i.e. the SiPM. Additionally, for several applications a more phenomenological and complete view on SiPMs has to be done, e.g. photon detection efficiency, single photon time resolution, SiPM signal response, gain fluctuation, dark count rate, afterpulse, prompt and delayed optical crosstalk. These quantities of SiPMs can strongly influence the time and energy resolution, for example in PET and HEP. Having a complete overview on all of these parameters allows to draw conclusions on how best performances can be achieved for the various needs of different applications.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 916〈/p〉 〈p〉Author(s): Xunchao Zhang, Lin Yu, Xuesong Yan, Yaling Zhang, Hanjie Cai, Jianyang Li, Zhilei Zhang, Liangwen Chen, Xiaofei Gao, Lei Yang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The concept of gravity-driven Dense Granular Target (DGT) has been proposed and tungsten granule is one of the candidate target materials. With the increase of DGT diameter, the source efficiency is significantly reduced, which is not conducive to the design of high-power. Low density porous tungsten particles are proposed as the target material of DGT instead of the natural tungsten. First, the neutronics of the bare target have been studied with porous tungsten granule density using Monte Carlo code. An ADS model was then set up to evaluate the neutron sources performance caused by density variation of porous tungsten granule. The results show that there is an optimal combination of tungsten granular density and target diameter to make the utmost of leakage neutrons. In the ADS driven by tungsten DGT, an appropriate density porous tungsten as the target material can effectively increase the source efficiency, reduce the beam requirement and the thermal deposition on the target.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 3 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): U.F. Katz〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cherenkov light induced by fast charged particles in transparent dielectric media such as air or water is exploited by a variety of experimental techniques to detect and measure extraterrestrial particles impinging on Earth. A selection of detection principles is discussed and corresponding experiments are presented together with breakthrough-results they achieved. Some future developments are highlighted.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 3 December 2018〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment〈/p〉 〈p〉Author(s): L. Sohl〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A hyper-fast time reference is needed for characterisation measurements of fast-timing detector prototype. The time resolution of the reference detector, normally placed together with a device under test (DUT) in a beam telescope, should be considerably better than the time resolution of the DUT. Measurements with MCP-PMTs of the type R3809U-50 by Hamamatsu have been performed in order to characterise their spatial distribution of the time resolution and to validate them as a proper reference detector. These measurements were conducted during the tests of PICOSEC fast-timing Micromegas prototypes at the CERN/SPS-H4 beam line using a beam telescope consisting of three triple-GEM tracker and various trigger detectors. A time resolution of up to 3.8 ps has been obtained in the inner part of the active area. In the outer parts, the time resolution declines up to several ten picoseconds due to decreasing pulse amplitudes. In this region, the Cherenkov light cone is not fully projected onto the photocathode anymore. Finally, only diffuse reflected light is reaching the photocathode in the outermost parts. The pulse amplitude correlates with the number of generated photo electrons and therefore with the amount of light reaching the photocathode. This explains the strong spatial differences of the MCP-PMTs time resolution.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Yingping Li, Yong Jia, Qi Zeng, Xiaohui Jiang, Zhengjun Cheng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We used thiamine nitrate (TN) as single material to fabricate nitrogen and sulfur co-doped carbon quantum dots (N,S-CQDs) with a quantum yield of 10.4% through one-pot hydrothermal method, and its properties were characterized by TEM, XPS, FTIR, fluorescence (FL) and UV–vis spectrophotometer, respectively. The fluorescence of N,S-CQDs was effectively quenched in the presence of vitamin B12 (VB12)/tartrazine due to Förster resonance energy transfer (FRET). Moreover, the rate (〈em〉K〈/em〉〈sub〉T〈/sub〉) and efficiency (〈em〉E〈/em〉%) of energy transfer from N,S-CQDs (as a donor) to VB12/tartrazine (as an acceptor) enhanced with increasing the concentrations of acceptor, and the 〈em〉K〈/em〉〈sub〉T〈/sub〉 and 〈em〉E〈/em〉% were also varied with the change of excitation wavelengths (from 338 to 408 nm). Based on this principle, a multifunctional fluorescence probe was designed for selective and sensitive detection of VB12/tartrazine with a detection limit (3σ/slope) of 15.6/18.0 nmol/L. Meanwhile, the proposed method was successfully employed to detect VB12/tartrazine in milk and several beverages with a recovery range of 97.5–104.2%/91.0–110.6%.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉N,S-CQDs as a multifunctional sensor has remarkable selectivity and high sensitivity for monitoring VB12/tartrazine, and the FL quenching of N,S-CQDs by VB12/tartrazine was further analyzed by FRET theory. The 〈em〉r〈/em〉 values decrease with increasing the concentration of acceptor (VB12/tartrazine) (A/B), and corresponding 〈em〉E〈/em〉% and 〈em〉K〈/em〉〈sub〉T〈/sub〉 values (C/D) show an opposite change tendency.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310643-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Xiao Wang, Yanmei Zhou, Chenggong Xu, Haohan Song, Xiaobin Pang, Xiaoqiang Liu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hydrazine (N〈sub〉2〈/sub〉H〈sub〉4〈/sub〉) and fluoride ion (F〈sup〉−〈/sup〉) are regarded as environmental pollutants and potential carcinogens. A dual-functional fluorescent probe (probe 〈strong〉1〈/strong〉) was developed for both F〈sup〉−〈/sup〉 and N〈sub〉2〈/sub〉H〈sub〉4〈/sub〉 with high selectivity and sensitivity. 〈strong〉1〈/strong〉 was based on nucleophilic aromatic substitution reaction for N〈sub〉2〈/sub〉H〈sub〉4〈/sub〉 detection and selective cleavage of 4-nitrobenzenesulphonyl group for the determination of F〈sup〉−〈/sup〉. The limits of detection of probe for F〈sup〉−〈/sup〉 and N〈sub〉2〈/sub〉H〈sub〉4〈/sub〉 were 77.82 nM and 29.34 nM, respectively, which are far below the threshold limit value (TLV) of United States Environmental Protection Agency (EPA). The home-made test strips of 〈strong〉1〈/strong〉 provided the positive tool for F〈sup〉−〈/sup〉 and gaseous N〈sub〉2〈/sub〉H〈sub〉4〈/sub〉 in different system. And the confocal fluorescence images indicated that 〈strong〉1〈/strong〉 can quantitatively detect N〈sub〉2〈/sub〉H〈sub〉4〈/sub〉 in living PC12 cells. Promisingly, 〈strong〉1〈/strong〉 has great prospects for N〈sub〉2〈/sub〉H〈sub〉4〈/sub〉 imaging and determining in living system.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉A 4-nitrobenzenesulphonyl group-cleavage based fluorescent probe was prepared for highly selective and sensitive dual-detection of fluoride ion and gaseous hydrazine on home-made test strips. This probe was successfully applied to quantitatively detect hydrazine in living cells.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310667-ga1.jpg" width="317" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Jian Zhu, Xiao-Hong Chen, Jian-Jun Li, Jun-Wu Zhao〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work, the novel tetrapod gold nanostars with four specific numbers of sharp tips were synthesized with good uniformity, high yield and chemical stability. The size of tetrapod gold nanostars has been increased effectively by increasing the amount of HAuCl〈sub〉4〈/sub〉 or DEA added to the reaction solution, and the corresponding in-plane localized surface plasmon resonance (LSPR) band can shift from 700 to 1100 nm. In order to combine the advantages of different metals, the Ag-coated tetrapod gold nanostars were prepared with different Ag coating thicknesses by increasing the volume of AgNO〈sub〉3〈/sub〉. With the increase of Ag coating thickness, the morphology of the nanoparticles has changed from gold nanostars with four sharp tips to bimetallic cuboids with four sharp tips and finally to crore-shell cuboids completely. The surface-enhanced Raman scattering (SERS) activity of Ag-coated tetrapod gold nanostars has also been improved with the different Ag coating thicknesses. Combined the tip effect and the enhancement effect of Ag, the SERS activity has the strongest enhancement when the four sharp tips of tetrapod gold nanostars are not completely coated by the Ag layer but still exposed to the outsides. For tetrapod gold nanostars with larger size to grow Ag-coated tetrapod gold nanostars, the bimetallic cuboids with four sharp tips nanostructure have the biggest SERS enhancement factor (EF) of 1.73 × 10〈sup〉6〈/sup〉 for Rhodamine 6G (R6G), making it an ideal candidate in SERS-based sensing application.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉The SERS activity has been strongly improved when the four sharp tips of tetrapod gold nanostars (In-plane LSPR at 916 nm) are not completely coated by the Ag layer but still exposed to the outsides.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310631-ga1.jpg" width="284" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Rupa Pegu, Gopal Pandit, Ankur Kanti Guha, Sajal Kumar Das, Sanjay Pratihar〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this report, 6〈em〉H〈/em〉-indolo[2,3-〈em〉b〈/em〉]quinoline (hereafter 〈strong〉2a〈/strong〉) was synthesized and employed as an optical chemosensor for fluoride. The sensitivity of 〈strong〉2a〈/strong〉 towards fluoride was established from the change in both the absorption and emission signals. The various 〈em〉in-situ〈/em〉〈sup〉1〈/sup〉H NMR, UV–Vis, and density functional studies indicate that the 1:2 binding interaction between 〈strong〉2a〈/strong〉 and fluoride followed by deprotonation to its corresponding di-anion (〈strong〉2a〈/strong〉〈sup〉〈strong〉2−〈/strong〉〈/sup〉), which in turn boosted the donor-acceptor interaction between indole and quinoline moiety in 〈strong〉2a〈/strong〉〈sup〉〈strong〉2−〈/strong〉〈/sup〉〈em〉via〈/em〉 expansion of torsion angle by 10.2° as compared to 〈strong〉2a〈/strong〉. Consequently the significant changes in both the absorption and emission signal of 〈strong〉2a〈/strong〉 allow us to detect and estimate the concentration of fluoride up to 0.2 μM from the mixture of different anions.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310618-ga1.jpg" width="431" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Hui Chen, Chao Tan, Zan Lin, Hongjin Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The authentication of traditional Chinese medicine (TCM) is critically important for public-health and economic terms. Notoginseng, a classical TCM of high economic and medical value, could be easily adulterated with 〈em〉Sophora flavescens〈/em〉 powder (SFP), corn flour (CF) or other analogues of low-grade (ALG) because of their similar tastes, appearances and much lower cost. The main objective of this study was to evaluate the feasibility of applying of near-infrared (NIR) spectroscopy and multivariate calibration for identifying and quantifying several common adulterants in notoginseng powder. Two datasets were prepared for experiment. The competitive adaptive reweighted sampling (CARS) was used to select informative variables. Two different schemes were used for sample set partition. Model population analysis (MPA) was made. The results showed that, the constructed partial least squares (PLS) model using a reduced set of variables from CARS can provide superior performance to the full-spectrum PLS model. Also, the sample set partition is very of great importance. It seems that the combination of NIR spectroscopy, CARS and PLS is feasible to quantify common adulterants in notoginseng powder.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310655-ga1.jpg" width="267" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 916〈/p〉 〈p〉Author(s): P.-A. Söderström, G. Jaworski, J.J. Valiente Dobón, J. Nyberg, J. Agramunt, G. de Angelis, S. Carturan, J. Egea, M.N. Erduran, S. Ertürk, G. de France, A. Gadea, A. Goasduff, V. González, K. Hadyńska-Klȩk, T. Hüyük, V. Modamio, M. Moszynski, A. Di Nitto, M. Palacz〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this work we present a comparison between the two liquid scintillators BC-501A and BC-537 in terms of their performance regarding the pulse-shape discrimination between neutrons and 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si9.gif"〉〈mi〉γ〈/mi〉〈/math〉 rays. Special emphasis is put on the application of artificial neural networks. The results show a systematically higher 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si9.gif"〉〈mi〉γ〈/mi〉〈/math〉-ray rejection ratio for BC-501A compared to BC-537 applying the commonly used charge comparison method. Using the artificial neural network approach the discrimination quality was improved to more than 95% rejection efficiency of 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si9.gif"〉〈mi〉γ〈/mi〉〈/math〉 rays over the energy range 150 to 1000 keV for both BC-501A and BC-537. However, due to the larger light output of BC-501A compared to BC-537, neutrons could be identified in BC-501A using artificial neural networks down to a recoil proton energy of 800 keV compared to a recoil deuteron energy of 1200 keV for BC-537. We conclude that using artificial neural networks it is possible to obtain the same 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll" altimg="si9.gif"〉〈mi〉γ〈/mi〉〈/math〉-ray rejection quality from both BC-501A and BC-537 for neutrons above a low-energy threshold. This threshold is, however, lower for BC-501A, which is important for nuclear structure spectroscopy experiments of rare reaction channels where low-energy interactions dominates.〈/p〉〈/div〉

Description: 〈p〉Publication date: 21 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 918〈/p〉 〈p〉Author(s): M. Kobayashi, T. Ogawa, A. Shoji, Y. Aoki, K. Ikematsu, P. Gros, T. Kawaguchi, D. Arai, M. Iwamura, K. Katsuki, A. Koto, M. Yoshikai, K. Fujii, T. Fusayasu, Y. Kato, S. Kawada, T. Matsuda, S. Narita, K. Negishi, H. Qi〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We have developed a gating foil for the time projection chamber envisaged as a central tracker for the international linear collider experiment. It has a structure similar to the Gas Electron Multiplier (GEM) with a higher optical aperture ratio and functions as an ion gate without gas amplification. The transmission rate for electrons was measured in a counting mode for a wide range of the voltages applied across the foil using an 〈sup〉55〈/sup〉Fe source and a laser in the absence of a magnetic field. The blocking power of the foil against positive ions was estimated from the electron transmissions.〈/p〉〈/div〉

Description: 〈p〉Publication date: 11 February 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 917〈/p〉 〈p〉Author(s): N. Fuster-Martínez, P. Bambade, A. Faus-Golfe, K. Kubo, S. Liu, T. Okugi, T. Tauchi, N. Terunuma, S. Wallon, R. Yang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A beam halo collimator was installed at the Accelerator Test Facility ATF2 in the spring of 2016. The main objective of the collimator is the reduction of background photons that limit the performance of key diagnostic devices around the Interaction Point, especially the Shintake Monitor, used for measuring the nanometer level vertical beam sizes, and the vertical and horizontal Diamond Sensors, used for transverse beam halo measurements. In this paper we present the simulations performed to optimize the efficiency of the collimator as well as the wakefield study performed in order to optimize the geometry and material of the collimator jaws. Finally, measurements of the cleaning efficiency and of the collimator induced wakefields impact on the orbit, performed during the Spring and Fall 2016 runs, are presented and compared with simulations.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 March 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉 〈p〉Author(s): Graham Hungerford, M. Adília Lemos, Boon-Seang Chu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The binding of an extract from the flowers of 〈em〉Clitoria ternatea〈/em〉 L. to the digestive enzyme α-amylase was investigated. This extract is a mixture of flavonoids, including anthocyanins, and has been previously shown to inhibit the activity this enzyme. This has implications for modulating starch digestion. In order to investigate the kinetics, we made use of time-resolved fluorescence to simultaneously monitor two different emission bands emanating from the extract. This measurement was enabled by the use of a “photon streaming” approach and changes in fluorescence lifetime and intensity were used to follow the interaction. A longer wavelength band (655 nm) was ascribed to anthocyanins in the mixture and these were observed to bind at a rate an order of magnitude slower than other flavonoids present in the extract, monitored at a shorter wavelength (485 nm). Changes in the fluorescence emission of the extract upon binding were further assessed by the use of decay associated spectra.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉Binding of 〈em〉C. ternatea〈/em〉 extract to α-amylase followed using time-resolved fluorescence monitoring 2 wavelengths simultaneously using a photon streaming approach.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S138614251831059X-ga1.jpg" width="480" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 212〈/p〉 〈p〉Author(s): Xiaojing Yang, Yingying Wang, Mei-xia Zhao, Wei Yang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉By introducing the S-aryl substituents at the central carbon on heptamethine cyanine, we have developed a near-infrared fluorescent probe Cy.7-PT. The probe had the high selectivity for the colorimetric detection of Cys/Hcy with the color changing from light green to blue. Cys could be quantitatively detected and the detection limit is 0.39 μM. Cell imaging and spiked samples experiments prove that the probe Cy.7-PT is suitable for monitoring and visualizing Cys in vitro and living cells.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518311120-ga1.jpg" width="500" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 212〈/p〉 〈p〉Author(s): Mao-Sen Xu, Chuan-Lu Yang, Mei-Shan Wang, Xiao-Guang Ma〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To evaluate the feasibility of the laser cooling of CuH molecule, we investigate the electronic properties, the vibrational and rotational characteristics of the molecule based on the multi-reference configuration interaction method with all-electron basis sets. The potential energy curves (PECs) of X〈sup〉1〈/sup〉Σ〈sup〉+〈/sup〉, A〈sup〉1〈/sup〉Σ〈sup〉+〈/sup〉, B〈sup〉1〈/sup〉Σ〈sup〉+〈/sup〉, a〈sup〉3〈/sup〉Σ〈sup〉+〈/sup〉, b〈sup〉3〈/sup〉Σ〈sup〉+〈/sup〉, e〈sup〉3〈/sup〉Σ〈sup〉+〈/sup〉, C〈sup〉1〈/sup〉П, D〈sup〉1〈/sup〉П, c〈sup〉3〈/sup〉П and d〈sup〉3〈/sup〉П states and the transition dipole moments between these states are calculated. The Schrödinger equation of nuclear movement is solved for each electronic state to obtain the rotational and vibration energy levels. The spectroscopic parameters are calculated based on the fitted analytical function from the PECs. The present results are in good agreement with the theoretical and experimental values available in the literature. The optical scheme of the laser cooling for CuH molecule is constructed with A〈sup〉1〈/sup〉Σ〈sup〉+〈/sup〉 ↔ X〈sup〉1〈/sup〉Σ〈sup〉+〈/sup〉 as the close-loop transition. Three lasers are necessary in each direction to maintain enough scattering photons because of the limited Franck-Condon factor of 0.78. The wavelengths of the pumping lasers are determined. The recoil temperature is 1.72 μk, which is the expected temperature to be reached through the method of the cooling below the doppler limit.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉The laser cooling scheme of CuH molecule has been constructed with the closed transition of A〈sup〉1〈/sup〉Σ〈sup〉+〈/sup〉 ↔ X〈sup〉1〈/sup〉Σ〈sup〉+〈/sup〉 and three pumping lasers.〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518311089-ga1.jpg" width="318" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 5 April 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 212〈/p〉 〈p〉Author(s): V. Charles Vincent, K. Kirubavathi, G. Bakiyaraj, K. Selvaraju〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The solution grown structure 4-hydroxy L-proline cadmium chloride (4HLPCC) single crystal has been done by means of X-ray diffraction method. The computational quantum mechanical modelling method was performed with B3LYP level and LanL2DZ basis set to determine optimized geometry, dipolar moment, linear polarizability, first order hyperpolarizability, atomic charges of various atoms, thermodynamic parameters, HOMO-LUMO energy gap and vibrational frequencies of 4HLPCC. The vibrational frequencies of 4HLPCC were observed experimentally through FTIR and FT-RAMAN analyses and compared with theoretical frequencies. The electric properties were detected by dielectric studies. The frequency doubling of the grown crystal was made with Kurtz-Perry powder technique.〈/p〉〈/div〉 〈/div〉 〈div xml:lang="en"〉 〈h5〉Graphical Abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518311077-ga1.jpg" width="347" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉 〈/div〉