ALBERT

Description: The literature discussing pulse-shape discrimination (PSD) in organic scintillators dates back several decades. However, little has been written about PSD techniques that are optimized for neutron spectrum unfolding. Variation in $n$ - $gamma $ misclassification rates and in $gamma /n$ ratio of incident fields can distort the neutron pulse-height response of scintillators and these distortions can in turn cause large errors in unfolded spectra. New applications in arms-control verification call for detection of lower-energy neutrons, for which PSD is particularly problematic. In this article, we propose techniques for removing distortions on pulse-height response that result from the merging of PSD distributions in the low-pulse-height region. These techniques take advantage of the repeatable shapes of PSD distributions that are governed by the counting statistics of scintillation-photon populations. We validate the proposed techniques using accelerator-based time-of-flight measurements and then demonstrate them by unfolding the Watt spectrum from measurement with a 252 Cf neutron source.

Description: A discretized positioning circuit (DPC) based on a resistive network has been developed to reduce the size of a gamma-ray detection system using multi-anode photomultiplier tubes (MA-PMT) in an array, because it can drastically decrease the number of output channels. The output signal from the gamma-ray detection system is a current pulse generated in each tube that contains information about the gamma-ray energy and detecting position in the array. The output current pulse is distributed to four outputs according to the resistance ratio of the resistive network in the DPC, and the detected position is estimated using the height values of the four distributed current pulses. However, owing to parasitic capacitors of MA-PMT connected in parallel to resistors in the resistive network, the four output pulses are affected by the RC time constants. In particular, when the duration of the input signal is not long enough, the height values of the distributed pulses are reduced, and thereby the position error increases significantly. In this paper, we present a new distortion correction method that considers the pulse duration and the RC time constant. In order to correct the position error, we employed homography, which is a coordinate transformation method. The ideal grid was mapped to a new grid for the distorted position. Using this method, error correction was completely achieved, even for short current pulses.

Description: There has been increased interest in organic semiconductors over the last decade because of their unique properties. Of these, 5, 6, 11, 12-tetraphenylnaphthacene (rubrene) has generated the most interest because of its high charge carrier mobility. In this work, large single crystals with a volume of ~1 cm 3 were grown from solution by a temperature reduction technique. The faceted crystals had flat surfaces and cm-scale, visually defect-free areas suitable for physical characterization. X-ray diffraction analysis indicates that solvent does not incorporate into the crystals and photoluminescence spectra are consistent with pristine, high-crystallinity rubrene. Furthermore, the response curve to pulsed optical illumination indicates that the solution grown crystals are of similar quality to those grown by physical vapor transport, albeit larger. The good quality of these crystals in combination with the improvement of electrical contacts by application of conductive polymer on the graphite electrodes have led to the clear observation of alpha particles with these rubrene detectors. Preliminary results with a 252 Cf source generate a small signal with the rubrene detector and may demonstrate that rubrene can also be used for detecting high-energy neutrons.

Description: The conventional front-end electronics for PET imaging consist of an energy circuit and a timing circuit. A single channel in front-end electronics typically requires several amplifiers, an ADC and a TDC. In this paper, we present a novel front-end electronic design using 1-bit sigma-delta ( $boldsymbol {Sigma }$ - $boldsymbol {Delta }$ ) modulation and an FPGA. The new design requires only one analog amplifier per channel. The output of the analog amplifier is read directly by the FPGA. Both the energy and timing calculation are implemented in FPGA firmware. The scope of this paper is to introduce the novel design in detail and to evaluate its performance in energy and dark current measurements. Simulink simulations were performed to validate the design with ideal components. A one-channel prototype circuit was built to assess the design with real components. The prototype circuit was tested with different input signals, including test pulses, pulse signals from a PMT detector, DC current signals and dark current signals from an SiPM sensor. Both the simulation and experimental results show that the method is inherently stable and has excellent accuracy and linearity in energy and dark current measurements. The prototype analog board was built with discrete components cost about $ 0.5 in total. The power consumption was about 20 mW. We conclude that the new method provides a cost-efficient and power-efficient way to accurately measure the energies of analog pulses and dark currents from detectors. The timing performance of this method is currently under evaluation.

Description: Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.

Description: Presents the table of contents for this issue of the publication.

Description: This paper reports on in situ measurements of the linear energy transfer spectra of galactic cosmic rays and their progeny and of trapped Van Allen belt protons as recorded by a pulse height analyzer (PHA) radiation spectrometer which flew on the STS-95 DISCOVERY mission on the Hubble Orbital Systems Test cradle. The shuttle was launched on October 29, 1998 and had a mission duration of 8.5 days during the minimum phase of the solar activity cycle. The orbit of the STS-95 was about 550 km altitude and 28.5° inclination. Close agreement was seen between radiation environment model predictions and the measurements of the PHA. Agreement is obtained by considering the directionality of the radiation interacting with the shuttle structure.

Description: This paper investigates the total ionizing dose (TID) response of nanoscaled field-effect transistors (FET) made of silicon multiple-gate nanowire (NW). The NWFET architecture relies on its remarkable electrostatic properties to push “silicon”-based technologies much deeper into device scaling than present FinFETs. However, as commonly observed when a new device or technology concept is proposed, such as shallow trench isolation and silicon-on-insulator or FinFET, TID effects reveal unexpected behaviors that can permanently modify pristine device electrical characteristics. This is why this paper discusses the impact of several parameters including the NWFET design and the transistor’s type to get thorough insights into the NWFET TID behavior.

Description: This paper presents a physical investigation of the mechanisms induced by the low temperature on single-event latchup in CMOS inverters for a range of technology nodes (250 nm from Sofradir and 180 nm from IBM). For the first time, the TCAD simulations show a good agreement of latchup characteristics with the experimental measurements at cryogenic temperatures. Additionally, a more robust technology provided by Sofradir was demonstrated.

Description: Reliable estimation of logic single-event upset (SEU) cross section is becoming increasingly important for predicting the overall soft error rate. As technology scales and single-event transient (SET) pulse widths shrink to widths on the order of the setup-and-hold time of flip-flops, the probability of latching an SET as an SEU must be reevaluated. In this paper, previous assumptions about the relationship of SET pulsewidth to the probability of latching an SET are reconsidered and a model for transient latching probability has been developed for advanced technologies. A method using the improved transient latching probability and SET data is used to predict logic SEU cross section. The presented model has been used to estimate combinational logic SEU cross sections in 32-nm partially depleted silicon-on-insulator (SOI) technology given experimental heavy-ion SET data. Experimental SEU data show good agreement with the model presented in this paper.

Description: Single-event cross sections of four inverter chains, with uniform inverter spacing ranging from 120 nm to $4~\mu \text{m}$ , were experimentally measured and compared. These inverter chains were irradiated using a focused ion beam. Full analog waveforms of responses were sensed using on-chip wide-bandwidth analog multiplexers. Cross sections are examined with respect to pulse heights and pulse widths, for direct-hit waveforms as well as for waveforms propagated through the chain. The influence of ion hit position and charge sharing effects on the initial shape and propagation of the single-event transients (SETs) was analyzed. We have observed a considerable reduction of cross section for tightly spaced inverters, for both direct hits and propagated SETs.

Description: In-flight feedback data are collected, such as displacement damage doses, ionizing doses, and cumulated Single Event upset (SEU) on board various space vehicles and are compared to predictions performed with: 1) proton measurements performed with spectrometers data on board the same spacecraft if any and 2) protons spectrum predicted by the legacy AP8min model and the AP9 and Onera Proton Altitude Low models. When an accurate representation of the 3-D spacecraft shielding as well as appropriate ground calibrations are considered in the calculations, such comparisons provide powerful metrics to investigate engineering model accuracy. To describe >30 MeV trapped protons fluxes, the AP8 min model is found to provide closer predictions to observations than AP9 V1.30.001 (mean and perturbed mean).

Description: A recent model provides risk estimates for the deprogramming of initially programmed floating gates via prompt charge loss produced by an ionizing radiation environment. The environment can be a mixture of electrons, protons, and heavy ions. The model requires several input parameters. This paper extends the model to include TID effects in the control circuitry by including one additional parameter. Parameters intended to produce conservative risk estimates for the Samsung 8 Gb SLC NAND flash memory are given, subject to some qualifications.

Description: Heavy-ion-induced degradation in the reverse leakage current of SiC Schottky power diodes exhibits a strong dependence on the ion angle of incidence. This effect is studied experimentally for several different bias voltages applied during heavy-ion exposure. In addition, TCAD simulations are used to give insight on the physical mechanisms involved.

Description: This paper presents an analysis of the efficiency of traditional fault-tolerance methods on parallel systems running on top of Linux OS. It starts by studying the occurrence of software errors at systems presenting different levels of complexity, from sequential bare metal to parallel Linux applications. Then two traditional fault-tolerance mechanisms (triple modular redundancy and duplication with comparison variant) are applied to the applications and their efficiency analyzed. All cases were tested at the single and dual-core versions of an ARM Cortex-A9 processor that is embedded in many commercial system-on-a-chip. The OVP simulator platform is used to instantiate the processor model and to inject faults into the system. Faults are modeled as bit flips in the processor registers. Results show that traditional fault-tolerance algorithms are not efficient enough to protect a whole parallel system running on top of an operating system, given that the operating system itself is a major source of errors.

Description: The control area network (CAN) wired communication standard is becoming the bus of choice for many space applications. However, the severe −2 to 7 V common-mode and −3 to 16 V failure tolerance requirements of the CAN bus driver have restricted its implementation of commercial high-voltage processes with transistors tolerant to voltages above 16 V. These transistors experience sensitivity to single-event gate rupture (SEGR) and single-event breakdown (SEB) radiation events and have led to the limited diffusion of commercial available CAN transceivers in space applications. This paper demonstrates, for the first time, that a radiation-tolerant CAN driver can also be realized with the radiation-tolerant low-voltage design against radiation effects (DARE) mixed-mode 180-nm CMOS technology. This has been made possible by the development of a specific driver circuit that increases in static and dynamic operations of the technology voltage handling range from 3.3 to 16 V, while maintaining the radiation tolerance. This CAN driver has been manufactured and tested under heavy ion radiation in excess of linear energy transfer (LET) of 60 MeVcm 2 /mg. Over the CAN common mode and failure tolerance voltage range up to 16 V, this CAN driver has been tested and found to have a high threshold and low cross section to radiation-induced single-electron transients and an absence of single-event latch-up, SEGR, and SEB sensitivity.

Description: We present experimental evidence of electron-induced upsets in a reference European Space Agency (ESA) single event upset (SEU) monitor, induced by a 200-MeV electron beam at the Very energetic Electronic facility for Space Planetary Exploration in harsh Radiation environments facility at CERN. Comparison of experimental cross sections and simulated cross sections is shown and the differences are analyzed. Possible secondary contributions to the upset rate by neutrons, flash effects, and cumulative dose effects are discussed, showing that electronuclear reactions are the expected SEU mechanism. The ESA Jupiter Icy Moons Explorer mission, to be launched in 2022, presents a challenging radiation environment due to the intense high-energy electron flux in the trapped radiation belts. Insight is given to the possible contribution of electrons to the overall upset rates in the Jovian radiation environment. Relative contributions of both typical electron and proton spectra created when the environmental spectra are transported through a typical spacecraft shielding are shown and the different mission phases are discussed.

Description: In this paper, we investigate the impact of register file errors in modern embedded microprocessors reliability through fault-injection and heavy-ion experiments. Additionally, we evaluate how different levels of compiler optimization modify the usage and failure probability of a processor register file. We select six representative benchmarks, each one compiled with three different levels of compiler optimization. We performed exhaustive fault-injection campaigns to measure the register’s architectural vulnerability factor of each code and configuration, identifying the registers that are more likely to generate silent data corruption or single event functional interruption. Moreover, we correlate the observed reliability variations with register file utilization. Finally, we irradiated with heavy ions two of the selected benchmarks compiled with two levels of optimization, and correlated experimental results with fault-injection analysis.

Description: We have presented a compact MOSFET model, which allows us to describe the current–voltage characteristics of irradiated long-channel and short-channel transistors in all operation modes at different measurement temperatures and interface trap densities. The model allows simulating of the OFF-state and the ON-state drain currents of irradiated MOSFETs based on an equal footing. Particularly, a novel compact model of the rebound effect in the n-MOSFETs was employed for the simulation of the total dose dependencies of drain currents in the highly scaled 60-nm node circuits irradiated up to 1 Grad. Compatibility of the model parameter set with BSIM and a single closed form of the model equation imply the possibility of its easy implementation into the standard CAD tools.

Description: Electrical behavior of commercial off-the-shelf normally-off GaN power transistors under heavy ion irradiation is presented based on technology computer aided design numerical simulation in order to better understand the mechanism of single event effects (SEEs) in these devices. First, the worst case has been defined from the single event transient mechanism. Then, the decrease in the electric field observed after irradiation and the traps effect have been addressed. Finally, possible mechanisms of SEE in these devices under heavy ion are proposed.

Description: We analyzed the delay failure induced in flash-based field-programmable gate arrays (FPGAs) exposed to total-ionizing dose. We developed a novel cell-level fault model for such delay failure. We introduced a novel methodology for identifying worst case test vectors (WCTVs) for flash-based FPGA devices exposed to total-ionizing dose based on the developed fault model for delay failure. We introduced a novel methodology to identify WCTVs for flash-based FPGAs using commercially available design and automatic test pattern generation tools. We validated the delay fault model using Microsemi ProASIC3 FPGAs and Cobalt 60 facility. The experimental results also show significant impact on the total-dose failure levels when using WCTVs.

Description: In digital image processing systems, the acquisition stage may capture impulsive noise along with the image. This physical phenomenon is commonly referred to as “salt-and-pepper” noise. The median filter is a nonlinear image processing operation used to remove this impulsive noise from images. This digital filter can be implemented in hardware to speed up the algorithm. However, an SRAM-based field-programmable gate array implementation of this filter is then susceptible to configuration memory bit flips induced by single event upsets, so a protection technique is needed for critical applications in which the proper filter operation must be ensured. In this paper, a fault-tolerant implementation of the median filter is presented and studied in-depth. Our protection technique checks if the median output is within a dynamic range created with the remaining nonmedian outputs. An output error signal is activated if a corrupted image pixel is detected, then a partial or complete reconfiguration can be performed to remove the configuration memory error. Experimental results show that our technique detects enough corrupted pixels in an image to prevent 91% of the corrupted images from being erroneously sent to the next image processing operation. This high error detection rate is achieved introducing only a 35% of additional resource overhead.

Description: In this paper, the suitability of floating gate dosimeter as total ionizing dose (TID) detector in mixed fields, representative of large hadron collider (LHC) radiation environment, has been investigated. Several experiments were performed in order to characterize the dosimeter. Exposures to $\gamma $ -ray were carried out to study the sensitivity and linearity of the radiation response. Experiments in mixed radiation field were performed at CERN High energy AcceleRator Mixed field facility (CHARM) at CERN together with RadFETs to compare the performances. In particular, the minimum dose to be cumulated in order to obtain the facility calibration factor has been evaluated and discussed. The effect of the temperature on the output signal has been characterized and a compensation method has been developed and implemented. The fading of the output after irradiation was measured in order to evaluate the retention of the analog information.

Description: This paper shows the impact of low linear energy transfer heavy ions on the reliability of 28-nm Bulk static random access memory (RAM) cells from Artix-7 field-programmable gate array. Irradiation tests on the ground showed significant differences in the multiple bit upset cross section of configuration RAM and block RAM memory cells under various angles of incidence and rotation of the device. Experimental data are analyzed at transistor level by using the single-event effect prediction tool called multiscale single-event phenomenon prediction platform coupled with SPICE simulations.

Description: This paper presents the characterization of the sensitivity to 14-MeV neutrons of a commercial off-the-shelf 90-nm static random access memories manufactured by Cypress Semiconductor, when biased at ultralow voltage. First, experiments exposing this memory at 14-MeV neutrons, when powering it up at bias voltages ranging from 0.5 to 3.3 V, are presented and discussed. These results are in good concordance with theoretical predictions issued by the modeling tool MUlti-SCAles Single Event Phenomena Predictive Platform . Then, this tool has been used to obtain soft error rate predictions at different altitudes above the Earth’s surface of this device versus its bias voltage. Finally, the effect of contamination by $\alpha $ particles has also been estimated at said range of bias voltages.

Description: The effects of radiation-induced defects and statistical variation in the dose and energy of MOSFET channel implants in a modern bulk CMOS technology are modeled using a process simulator in combination with analytical computations. The model integrates doping profiles obtained from process simulations and experimentally determined defect potentials into implicit surface potential equations. Solutions to these equations are used to model radiation-induced edge leakage currents in 90-nm bulk CMOS n-channel MOSFETs. The results indicate that slight variations in the channel implant parameters can have a significant impact on the doping profile along the shallow trench isolation sidewall and thus the radiation-induced edge leakage currents.

Description: In this paper, we investigate neutron-induced errors in three implementations of sort algorithms (QuickSort, MergeSort, and RadixSort) executed on modern graphics processing units designed for high-performance computing and large server applications. We measure the radiation-induced error rate of sort algorithms taking advantage of the neutron beam available at the Los Alamos Neutron Science Center facility. We also analyze output error criticality by identifying specific output error patterns. We found that radiation can cause wrong elements to appear in the sorted array, misalign values as well as application crashes or system hangs. This paper presents results showing that the criticality of the radiation-induced output error pattern depends on the application. Additionally, an extensive fault-injection campaign has been performed. This campaign allows for better understanding of the observed phenomena. We take advantage of SASS-assembly Intrumentator Fault Injector developed by NVIDIA, which can inject faults into all the user-accessible architectural state. Comparing fault-injection results with radiation experiments data provides an understanding that not all the output errors observed under radiation can be replicated in fault injection. However, fault injection is useful in identifying possible root causes of the output errors observed in radiation testing. Finally, we take advantage of our experimental and analytical study to design efficient experimentally tuned hardening strategies. We detect the error patterns that are critical to the final application and find the more efficient way to detect them. With an overhead as low as 16% of the execution time, we are able to reduce the output error rate of sort of about one order of magnitude.

Description: The enhanced low dose rate sensitivity (ELDRS) susceptibility of 2N2222 bipolar transistors and LM111 voltage comparators was investigated during irradiation at low temperature and compared with corresponding room-temperature data. The possible physical mechanism of the ELDRS effect in bipolar transistors and integrated circuits during irradiation at room temperature and low temperature was described. A device that is ELDRS-free at room temperature suffers from this effect during irradiation at low temperature.

Description: Single-event multiple transients (SEMTs) are investigated using an on-chip self-triggered circuit. Measured results for inverter chains of two layout designs, including a guard-ring design and a conventional design, are compared under pulsed laser and heavy-ion (Bi) irradiations. Pulsed laser exposures of different energies and Bi heavy-ion irradiation at different injection angles, including along the well direction and across the well direction, are found to produce SEMTs with different probabilities. The use of a guard-ring hardening technique is demonstrated to be very effective in reducing production of SEMTs for inverters without direct electrical connection. Charge sharing-induced SEMTs are found to have different pulsewidth distributions for angled ion incidence than normal ion or laser incidence.

Description: A single event latchup (SEL) experiment based on commercial static random access memory (SRAM) memories has recently been proposed in the framework of the European Organization for Nuclear Research (CERN) Latchup Experiment and Student Satellite nanosatellite low Earth orbit (LEO) space mission. SEL characterization of three commercial SRAM memories has been carried out at the Paul Scherrer Institut (PSI) facility, using monoenergetic focused proton beams and different acquisition setups. The best target candidate was selected and a circuit for SEL detection has been proposed and tested at CERN, in the CERN High Energy AcceleRator Mixed-field facility (CHARM). Experimental results were carried out at test locations representative of the LEO environment, thus providing a full characterization of the SRAM cross sections, together with the analysis of the single-event effect and total ionizing dose of the latchup detection circuit in relation to the particle spectra expected during mission. The setups used for SEL monitoring are described, and details of the proposed circuit components and topology are presented. Experimental results obtained both at PSI and at CHARM facilities are discussed.

Description: A simple physical model for calculation of the ion-induced soft error rate in space environment has been proposed, based on the phenomenological cross-sectional notion. The proposed numerical procedure is adapted to the multiple cell upset characterization in highly scaled memories. Nonlocality of the ion impact has been revealed as the key concept determining the difference between physical processes in low-scaled and highly scaled memories. The model has been validated by comparison between the simulation results and the literature on-board data. It was shown that the proposed method provides single-valued prediction results correlating well with on-board data-based solely on cross-sectional data and LET spectra without any hidden fitting parameters and procedures.

Description: This paper addresses a well-known problem that occurs when memories are exposed to radiation: the determination if a bit flip is isolated or if it belongs to a multiple event. As it is unusual to know the physical layout of the memory, this paper proposes to evaluate the statistical properties of the sets of corrupted addresses and to compare the results with a mathematical prediction model where all of the events are single bit upsets. A set of rules easy to implement in common programming languages can be iteratively applied if anomalies are observed, thus yielding a classification of errors quite closer to reality (more than 80% accuracy in our experiments).

Description: A low-noise head amplifier has been developed for the extra low energy antiproton ring beam trajectory, orbit, and intensity measurement system at CERN. This system is based on 24 double-electrode electrostatic beam position monitors installed around the ring. A head amplifier is placed close to each beam position monitor to amplify the electrode signals and generate a difference and a sum signal. These signals are sent to the digital acquisition system, about 50 m away from the ring, where they are digitized and further processed. The beam position can be measured by dividing the difference signal by the sum signal while the sum signal gives information relative to the beam intensity. The head amplifier consists of two discrete charge preamplifiers with junction field effect transistor (JFET) inputs, a sum and a difference stage, and two cable drivers. Special attention has been paid to the amplifier printed circuit board design to minimize the parasitic capacitances and inductances at the charge amplifier stages to meet the gain and noise requirements. The measurements carried out on the head amplifier showed a gain of 40.5 and 46.5 dB for the sum and difference outputs with a bandwidth from 200 Hz to 75 MHz and an input voltage noise density lower than $400~\text {pV}/\surd \text{Hz}$ . Twenty head amplifiers have been already installed in the ring and they have been used to detect the first beam signals during the first commissioning stage in November 2016.

Description: This paper presents the detailed characterization of a single photon counting chip, named CHASE Jr., built in a CMOS 40-nm process, operating with synchrotron radiation. The chip utilizes an on-chip implementation of the C8P1 algorithm. The algorithm eliminates the charge sharing related uncertainties, namely, the dependence of the number of registered photons on the discriminator’s threshold, set for monochromatic irradiation, and errors in the assignment of an event to a certain pixel. The article presents a short description of the algorithm as well as the architecture of the CHASE Jr., chip. The analog and digital functionalities, allowing for proper operation of the C8P1 algorithm are described, namely, an offset correction for two discriminators independently, two-stage gain correction, and different operation modes of the digital blocks. The results of tests of the C8P1 operation are presented for the chip bump bonded to a silicon sensor and exposed to the 3.5- $\mu \text{m}$ -wide pencil beam of 8-keV photons of synchrotron radiation. It was studied how sensitive the algorithm performance is to the chip settings, as well as the uniformity of parameters of the analog front-end blocks. Presented results prove that the C8P1 algorithm enables counting all photons hitting the detector in between readout channels and retrieving the actual photon energy.

Description: This paper studies perspectives on using optical fibers and distributed fiber sensing schemes to perform real-time-distributed gamma-ray radiation sensing with high spatial resolution. The radiation-induced optical property changes of aluminum-doped fibers were studied using cobalt-60 sources. The distributed optical loss of the aluminum-doped fiber was characterized using the Rayleigh backscattering optical frequency domain reflectometry (Rayleigh OFDR). The optical loss of unprotected fiber under various gamma dose rates remains linear up to 100 grays (Gy). Using the gamma radiation-sensitive fiber, the localized optical loss measured by the Rayleigh OFDR was used to map the accumulated gamma radiation dosage on the entire surface of the cylinder with a 1-cm spatial resolution. Using electrical cables as a ubiquitous sensor platforms for fiber sensor deployment, this paper explores the potential for multifunctional distributed fiber sensor by integrating distributed fiber temperature and gamma ionizing radiation sensors in electrical cables for multifunctional measurements to improve the safety of nuclear power systems at both the component and system levels. As sensors that can readily be embedded in a wide variety of materials and structures, radiation-sensitive fibers can be low-cost and highly flexible tool to gauge the performance degradation and longevity of materials and components used in the nuclear power systems.

Description: In this paper, we present a newly constructed analyzer dedicated to measuring the activity of a variety of radioisotopes with an emphasis on the delayed coincidence method. The analyzer acquires arriving pulses whose amplitudes exceed the preset voltage threshold by selectively storing the sampled incoming voltage pulses. This creates data sets that are marked with additional time stamps. These data are given as a sequence, allowing the detection of decay pairs and different types of afterpulses or reduction of the detector’s background. Here, the pulse analyzer was verified with a thick $\alpha $ and $\beta $ sources from 232 Th and 238 U decay chains and a $\beta $ source from 40 K. The simultaneous pulse height, pulse shape, and time interval measurement allowed the differentiation of $\beta /\alpha $ pulse pairs arising from 212 Bi/ 212 Po, 214 Bi/ 214 Po decay pairs with 300 ns and 160 $\mu \text{s}$ polonium half-life, respectively.

Description: Static RAM-based field programmable gate arrays (SRAM-based FPGAs) are widely adopted in trigger and data acquisition systems of high-energy physics detectors for implementing fast logic due to their reconfigurability, large real-time processing capabilities and embedded high-speed serial IOs. These devices are sensitive to radiation-induced upsets, which may alter the functionality of the implemented circuit. Presently, their usage on-detector is limited and there is a strong interest in finding solutions for improving their tolerance to radiation-induced upsets. In this paper, we show a novel configuration-redundancy generation and scrubbing technique for SRAM-based FPGAs. It leads to a power saving with respect to other solutions in the literature. Moreover, our technique is compatible with several Xilinx FPGA families. Our solution does not require neither the usage of external memories nor third-party layout tools. We describe an example of our solution applied to a benchmark design implemented in a Xilinx Kintex-7 FPGA. In order to prove the effectiveness of the solution, we present results from a proton irradiation test.

Description: A pressurized water reactor (PWR) is most suitable for load-following operation because of its self-regulating nature. However, rapid power maneuvering at an enhanced rate is heavily constrained by the overall power coefficient of reactivity which depends on both the reactor neutronics and thermal hydraulics. In this paper, a 100 MWe PWR module with an integrated steam generator, is modeled using the nonlinear equations representing both the neutronics and thermal hydraulics. Such a PWR is typically an integrated structure with a steam generator included in the same casing and can either be connected to the grid or connected with other such modules using a multimodular approach to constitute a Nuclear Steam Supply System (NSSS) driving a common turbine and an alternator. In this paper, Nonlinear Dynamic Inversion (NDI) technique is used to design a controller capable of controlling such a reactor for load-following with frequent changes in demand, in both the modes of operation, namely, reactor-follow-turbine and turbine-follow-reactor. With the assumption that the parameters of the reactor vary within intervals as the power varies, an interval approach coupled with NDI ensures that the controller satisfies the operating constraints. The methodology is established for both the modes with credible real-time Hardware-in-Loop (HiL) simulations.

Description: Voltage reference is the key module in analog and mixed-signal integrated circuits. This paper presents a radiation-hardened CMOS negative voltage reference for aerospace electronics. To improve the antiradiation performance, in the circuit design, the input pair of the operational amplifier is replaced from pMOS to nMOS. An extra unity-gain amplification stage is added and the compensation network is optimized. Besides, the start-up circuit is redesigned. In the layout design, the annular-gate structure is adopted to eliminate electric leakage, while the layout technique against single-event latch-up is also used. The prototype of the proposed circuit is fabricated using a bulk CMOS 0.6- $\mu \text{m}$ process with a $547\,\, \mu \text {m} \times 618\,\, \mu \text {m}$ chip area. By using the proposed circuit and layout optimizations, the measured temperature coefficient of reference is reduced to 13 ppm/°C and the output voltage drift is below 1.2% after 300-krad(Si) total ionizing dose. The measured single-event latch-up threshold is above 94.6 MeVcm 2 /mg.

Description: Due to current technology scaling trends, digital designs are becoming strongly susceptible to space radiation effects. These effects can cause unwanted single-event upsets (SEUs) in any state element. This paper presents a new system-level model of SEUs propagation through processors as a continuous-time Markov chain (CTMC). Moreover, probabilistic formal techniques (such as probabilistic model checking) are utilized to exhaustively estimate the impact of SEUs on the system behavior. The proposed CTMC model was analyzed for different SEU injection scenarios and different bit-flip rates. Results demonstrate that the proposed approach can provide an accurate estimation of different reliability metrics, such as mean time to failure, mean time to recover, and the probability of failure for each SEU injection scenario in the system’s subcomponents. Furthermore, the proposed probabilistic system-level analysis was utilized to investigate the optimal self-repair rate required in the system to obtain the desired level of reliability. Results demonstrate that in comparison with existing simulation techniques for fault impact evaluation, the presented approach can provide consistent results while being orders of magnitude faster in terms of CPU time.

Description: A tunable wavelength laser system and high-resolution transient capture system are introduced to characterize transients in high-mobility MOSFETs. The experimental configuration enables resolution of fast transient signals and new understanding of charge collection mechanisms. The channel layer is critical in the charge collection process for the InGaAs FinFETs examined here. The transient current mainly comes from the channel current, due to shunt effects and parasitic bipolar effects, instead of the junction collection. The charge amplification factor is found to be as high as 14, which makes this technology relatively sensitive to transient radiation. The peak current is inversely proportional to the device gate length. Simulations show that the parasitic bipolar effect is due to source-to-channel barrier lowering caused by hole accumulation in the source and channel. Charge deposited in the channel causes prompt current, while charge deposited below the channel causes delayed and slow current.

Description: Reductions in single-event (SE) upset (SEU) rates for sequential circuits due to temporal masking effects are evaluated. The impacts of supply voltage, combinational-logic delay, flip-flop (FF) SEU performance, and particle linear energy transfer (LET) values are analyzed for SE cross sections of sequential circuits. Alpha particles and heavy ions with different LET values are used to characterize the circuits fabricated at the 40-nm bulk CMOS technology node. Experimental results show that increasing the delay of the logic circuit present between FFs and decreasing the supply voltage are two effective ways of reducing SE error rates for sequential circuits for particles with low LET values due to temporal masking. SEU-hardened FFs benefit less from temporal masking than conventional FFs. Circuit hardening implications for SEU-hardened and unhardened FFs are discussed.

Description: The single-event sensitivity of bulk 40-nm sequential circuits is investigated as a function of temperature and supply voltage. An overall increase in SEU cross section versus temperature is observed at relatively high supply voltages. However, at low supply voltages, there is a threshold temperature beyond which the SEU cross section decreases with further increases in temperature. Single-event transient induced errors in flip-flops also increase versus temperature at relatively high supply voltages and are more sensitive to temperature variation than those caused by single-event upsets.

Description: The single-event upset (SEU) vulnerability of common first- and second-order all-digital-phase-locked loops (ADPLLs) is investigated through field-programmable gate array-based fault injection experiments. SEUs in the highest order pole of the loop filter and fraction-based phase detectors (PDs) may result in the worst case error response, i.e., limit cycle errors, often requiring system restart. SEUs in integer-based linear PDs may result in loss-of-lock errors, while SEUs in bang-bang PDs only result in temporary-frequency errors. ADPLLs with the same frequency tuning range but fewer bits in the control word exhibit better overall SEU performance.

Description: The August 2017 special issue of the IEEE Transactions on Nuclear Science contains more than 40 selected, peer-reviewed, journal articles that were prepared on the basis of presentations made at the 2016 Conference on Radiation and Its Effects on Components and Systems (RADECS) held on September 19–23, 2016, in Bremen, Germany. A few additional papers may appear in subsequent issues of the Transactions. A full conference record of RADECS 2016 will also be available in the IEEE Xplore.

Description: The very high radiation fluences expected at the high-luminosity large hadron collider (LHC) impose new challenges in terms of design of radiation resistant silicon detectors. The choice to use p-type substrates to improve the charge collection efficiency involves an optimization of the strip isolation to interrupt the inversion layer between the $n^{+}$ implants, limiting the breakdown voltage. To this purpose, TCAD modeling and simulation schemes, already developed and validated at typical LHC fluences have to be adapted to take into account effects usually neglected at lower fluences. To better understand in a comprehensive framework, the complex and articulated phenomena related to bulk and surface radiation damage, measurements on test structures and sensors, as well as TCAD simulations related to bulk, surface and interface effects, have been carried out. In particular, we have studied the properties of the SiO 2 layer and of the Si-SiO 2 interface, using MOS capacitors and gate-controlled diodes (gated diodes) manufactured by different vendors on a high-resistivity p-type silicon before and after irradiation with X-rays in the range from 50 krad to 10 Mrad. In this paper, we present the results of the experimental characterizations as well as the simulation findings, in order to analyze the effects of the interface traps on the strip isolation. This analysis helps us to validate the model and to identify the most sensitive technological and design parameters to be optimized for the design of advanced 2-D and 3-D silicon radiation detectors.

Description: This paper revisits the stochastic computing paradigm as a way to implement architectures dedicated to probabilistic inference. In general, it is assumed the operation over stochastic bit streams is robust with respect to radiation transient events effects. Moreover, it can be expected that leveraging the stochastic computing paradigm to implement probabilistic computations such as Bayesian inference implemented in hardware could yield an increased resilience to radiation effects comparatively to deterministic procedures. However, the practical assessment of the robustness against radiation is mandatory before considering stochastic Bayesian machines (SBMs) in hazardous environments. Results of fault injection campaigns at register transfer level provide the first evidences of the intrinsic robustness of SBMs with respect to single event upsets and single event transients.

Description: This paper aims at better defining the scope of applicability of a 14-MeV neutron source for single-event effect characterization. Based on an analysis of the neutron nuclear recoils and experiments on multiple devices (SRAM, SDRAM, FPGA) and feature sizes, the data are compared with results gathered with white neutron beams. As expected, the results are close for single-event upset in most technologies but, for most devices, the higher energy atmospheric spectra produce more multiple-cell upset and single-event latch-up. Finally, a simplified model is proposed to extrapolate 14-MeV neutron data to terrestrial environments.

Description: This paper shows the impact of low fluence neutron irradiation on AlInN/GaN HEMTs before and after a negative gate bias stress done at a gate-to-source voltage ( $V_{\text {GS}})$ of −20 V and at a drain-to-source voltage ( $V_{\text {DS}})$ of 0 V during 216 h. We have shown that the neutron irradiation induces a decrease in the drain current of 6% and an increase in access resistance of 8% for the unstressed component in opposite to the stressed component. In fact, a rise in drain current of 9% and no evolution of the access resistance have been observed for a stressed AlInN/GaN HEMT. This phenomenon is related to the formation of complex cluster between the electron traps induced by the aging test and those involved by the neutron irradiation.

Description: Recoil of constituent nuclei from neutron elastic scatter in pixelated, 3-D CdZnTe gamma-ray detectors is detectable given current low energy thresholds. Fast neutrons are attenuated by CdZnTe detectors via outscatter and measured gradients in neutron interaction rates across detector pixels that enables 1-D fast neutron source localization through a maximum likelihood estimator. Experimental results using an MP320 deuterium–deuterium neutron generator with the four detector crystal Orion prototype successfully localize four different source locations across a 1-D field of view to within absolute measurement errors between 2.5° and 14.0°.

Description: Under radiation environment, conventional SRAMs suffer from high soft-error rate. To address this challenge, several radiation-hardened static-random access-memory (SRAM) cells such as twelve-transistor (12T) Dice and ten-transistor (10T) Quatro have been developed. Quatro is more promising since this cell delivers robust operation while incurring moderate area overhead. However, our study shows that Quatro experiences large number of write failures under parametric variations of scaled technologies, impeding the application of this SRAM cell. In this paper, we present a 12T SRAM cell named as we-Quatro. In spite of using more transistors, the proposed SRAM cell occupies essentially the same area as Quatro. Our extensive simulations show that the proposed cell provides good writability and comparable soft-error resilience to Quatro under parametric variations of 28-nm fully depleted SOI technology, validating the efficacy of our proposed we-Quatro.

Description: A total of ten jacketed single-spoke resonators type 1 (SSR1) have been fabricated for Fermilab’ injection experiment (PIP2IT). PIP2IT is a test bed for Fermilab’s future accelerator named proton improvement plan II that is currently under development. SSR1 cavities operate at 325 MHz to accelerate a proton beam at a relative (to speed of light) velocity ( $\beta = 0.22$ ). In this paper, we present Fermilab’s experience in developing those spoke resonators starting from the design and analysis phase, to fabrication and extensive testing to qualify cavities for cryomodule assembly.

Description: The absorbed X-ray dose was measured during 35 fs pulsed laser ablation of a high purity molybdenum target in ambient conditions for optical intensities from $1.8 \times 10^{14}$ to $1.6 \times 10^{15}$ W/cm 2 (0.5–4.5 mJ per pulse) at a repetition rate of 1 kHz. During 1 s of ablation, at a distance of 6 cm from the source, appreciable X-ray dose was observed at all optical intensities, ranging from $0.08~\mu $ Gy, at the minimum intensity, to $0.97~\mu $ Gy at the maximum intensity, corresponding to equivalent dose rates of 0.3–3.5 mSv/h. At the highest optical intensity, an absorbed dose of $0.29~\mu $ Gy was measured at a distance of 12 cm from the source, corresponding to an equivalent dose rate of 1.1 mSv/h. Characterization of the laser plasma emissions showed X-rays with energies approaching 20 keV at higher laser pulse energies. In Canada, the annual equivalent dose limit for nonradiation workers is 1 mSv. Our findings suggest that under certain conditions it is possible to exceed this dosage in as little as an hour of fs-laser material processing in ambient conditions. As such, workers in these environments may need to be trained in radiation safety, equipped with personal dosimeters, and provided proper radiation shielding.

Description: Monoenergetic pulsed proton beams at energies of 1 and 3 MeV per proton have been employed to characterize a segmented double-sided silicon strip detector. The detector is manufactured from a neutron transmutation doped silicon wafer and features a bulk resistivity of $2300~\Omega \cdot \text {cm}$ . Signals from both P-side and N-side strips have been digitized at 14 b, 100 MS/s. The beam was focused either in the middle of one strip or on the gap in between two strips. Energy resolution, charge collection time, and interstrip effects (charge sharing, charge losses, and inverted polarity pulses) have been investigated at different bias voltages and for particles entering either from the junction side or from the ohmic side.

Description: In the context of the development of an in-beam time-of-flight positron emission tomography demonstrator dedicated to the in vivo monitoring of delivered dose in hadrontherapy, we evaluate the potential performance of front-end architectures based on sampling and digital pulse processing to reconstruct the energy and time of event. In this paper, we evaluate the requirements for sampling frequency and analog-to-digital converter (ADC) resolution. The timing algorithm is a digital adaptation of the constant fraction discriminator principle, with a step of interpolation using a low-pass filter based on the cubic spline technique. We demonstrate the interest of the interpolation to lower the sampling frequency requirement, by improving the signal reconstruction compared with a simple linear interpolation. Experimental tests were performed on pulse libraries acquired from a set up composed of LYSO and LaBr 3 scintillators coupled to H6533 photomultipliers, and a sampling oscilloscope operating at 10 GHz. By offline processing of the signals with variable parameters (initial frequency, interpolator bandwidth, resampling frequency, and ADC resolution), we examined the impact of these parameters on time resolution. Results for the tested detectors suggest a minimal required sampling rate of 1.5 GHz, while the ADC resolution can be as small as 5 b. A logarithmic ADC could be more efficient, with a strict minimum of 4 b.

Description: In developing a signal separation algorithm, an obvious challenge relates to the ways in which the photon measurements from dual-tracer positron emission tomography (PET) are overlapped. Aside from this issue, the ill-conditioning and the noisy measures are still obstacles to achieve accurate and robust result. In this paper, we develop a novel approach from a data-driven perspective that separates dynamic dual-tracer PET signals into individual-tracer components explicitly with a simultaneous-injection single-scan. Our approach is divided into two phases: training and reconstruction. In the training phase, our proposed framework will learn the potential relationship of different frames for dynamic dual-tracer PET data. In the reconstruction phase, given the sinogram of a dual tracer, the PET activity map of an individual tracer can be obtained directly. Experiments on Monte Carlo simulation data sets are conducted as validation. The experimental results have demonstrated the superior performance of the proposed approach by comparing with the ground truth of the individual-tracer.

Description: RapidIO ( http://rapidio.org/ ) technology is a packet-switched high-performance fabric, which has been under active development since 1997. The technology is used in all 4G/LTE base stations worldwide. RapidIO is also used in embedded systems that require high reliability, low latency, and deterministic operations in a heterogeneous environment. RapidIO has several offloading features in hardware, therefore relieving the CPUs from time- and power-consuming work. Most importantly, it allows for remote direct memory access and thus zero-copy data transfer. In addition, it lends itself readily to integration with field-programmable gate arrays. In this paper, we investigate RapidIO as a technology for high-speed data acquisition (DAQ) networks, in particular the DAQ system of an LHC experiment. We present measurements using a generic multiprotocol event-building emulation tool that was developed for the LHCb experiment. Event building using a local area network, such as the one foreseen for the future LHCb DAQ, puts heavy requirements on the underlying network as all data sources from the collider will want to send to the same destinations at the same time. This may lead to an instantaneous overcommitment of the output buffers of the switches. We will present results from implementing an event building cluster based on RapidIO interconnect, focusing on the bandwidth capabilities of the technology as well as its scalability.

Description: To assess function of various organs as well as recognize malignancy in its initial stages, single photon emission computed tomography system is employed in which the collimators can obtain the qualified images toward better diagnostic on the lesions and metabolic performance. Although new designs and optimized methods as well as the analytical models have been proposed to improve tradeoff between resolution and sensitivity in the collimators, but opposing behavior of them still remains as one of the major problems associated with the parallel hole collimators (PCs). In this paper, a new design, namely, extended parallel hole collimator (EPC) in which trapezoidal denticles are added upon the collimator septa at the detector side, has been proposed to improve performance of the PCs. Two PCs as PC 35 and PC 41 with hole sizes of 1.5 mm and hole lengths of 35 and 41 mm, respectively, are considered for comparison and investigation of the EPC performance. Theory and Monte Carlo simulations have been carried out to evaluate some of its related parameters such as sensitivity, resolution, and contrast. To reconstruct the tomographic images of Jaszczak phantom, the maximum-likelihood expectation maximization algorithm is chosen. The results have been indicated that the EPC has increased the amount of sensitivity as 10.2% compared to the PCs at the same resolution, and decreased the penetrating ratio as well as produced the tomographic images with lower noise coefficient (NC%), and improved contrast to noise ratio. Finally, it is found that the EPC may obtain the qualified images.

Description: Presents the front cover for this issue of the publication.

Description: Presents the reviewers who contributed to the 2016 Conferenceon Radiation and its Eddects on Components and Systems (RADECS), that was held in Bremen, Germany, September 19–23, 2016.

Description: HfO 2 -based resistive RAMs have been irradiated with high-linear energy transfer heavy ions and subjected to an extensive characterization, showing that the cells are immune from upsets. No relevant changes were observed in the irradiated cells on resistance distribution and programming voltages. The irradiation experiment has been performed without any applied bias (retention mode). Reasons for the observed hardness are discussed using physics-based simulations. Moreover, simulations put in evidence that the cell might be sensitive if it is struck during a read operation, since the applied read voltage prevents the instantaneous recombination of the generated defects due to the Coulomb interaction between oxygen ions and vacancies.

Description: The propagation of single-event transient (SET) signals in a silicon–germanium direct-conversion receiver carrying modulated data is explored. A theoretical analysis of transient propagation, verified by simulation, is presented. A new methodology to characterize and quantify the impact of SETs in communication systems carrying modulated data is proposed. The proposed methodology uses a pulsed radiation source to induce distortions in the signal constellation. The error vector magnitude due to SETs can then be calculated to quantify errors. Two different modulation schemes were simulated: QPSK and 16-QAM. The distortions in the constellation diagram agree with the presented circuit theory. Furthermore, the proposed methodology was applied to evaluate the improvements in the SET response due to a known radiation-hardening-by-design (RHBD) technique, where the common-base device of the low-noise amplifier was operated in inverse mode. The proposed methodology can be a valid technique to determine the most sensitive parts of a system carrying modulated data.

Description: Presents the front cover for this issue of the publication.

Description: Presents the table of contents for this issue of the publication.

Description: This is a special issue of the IEEE Transactions on Nuclear Science containing papers from the invited, oral, and poster presentation of the 20th Real Time Conference (RT2016). The conference was held June 6–10, 2016, at Centro Congressi Padova “A. Luciani,” Padova, Italy, and was organized by Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA) and the Istituto Nazionale di Fisica Nucleare. The Real Time Conference is multidisciplinary and focuses on the latest developments in real-time techniques in high-energy physics, nuclear physics, astrophysics and astroparticle physics, nuclear fusion, medical physics, space instrumentation, nuclear power instrumentation, general radiation instrumentation, and real-time security and safety. Taking place every second year, it is sponsored by the Computer Application in Nuclear and Plasma Sciences technical committee of the IEEE Nuclear and Plasma Sciences Society. RT2016 attracted more than 240 registrants, with a large proportion of young researchers and engineers. It had an attendance of 67 students from many countries.

Description: Laser calibration facilities play a key role in the study and characterization of detectors like electromagnetic or hadronic calorimeters. They can be operated both during physics data taking and off runs. Typically, these facilities are based on a laser source which delivers light to each detector element via a light distribution system. The laser control (LC) system typically manages the interface between the experiment and the laser source, allowing the generation of light pulses according to specific needs such as detector calibration, study of detector performance in running conditions, and evaluation of data acquisition performance. Any specific implementation depends on hardware features. As an example, light pulses could be generated according to a physics distribution during physics runs or real data taking. In this case, light pulses should be generated according to a pattern that follows a programmable function and changes on a statistical base event by event. In this paper, we present a LC system for calibration of a calorimeter. It is a custom solution based on a hybrid platform hosting a field-programmable gate array and an ARM processor. We present the system architecture and the performances of a preliminary implementation. This system, in a more specific and specialized version, will be used in the Muon g-2 experiment (E989) at Fermilab.

Description: The LHCb experiment uses the LHC accelerator for the collisions that produce the physics data necessary for analysis. The data produced by the detector by measuring the results of the collisions at a rate of 40 MHz are read out by a complex data acquisition (DAQ) system, which is summarily described in this paper. Distributed systems of such dimensions rely on monitoring and control systems that account for the numerous faults that can happen throughout the whole operation. With this in mind, a new system was created to extend the monitoring of the readout system, in this case by providing an overview of what is happening in each stage of the DAQ process, starting in the hardware trigger performed right after the detector measurements and ending in the local storage of the experiment. This system, a complement to the current run control (experimental control system), intends to shorten reaction times when a problem occurs by providing the operators with detailed information of where a certain fault is occurring. The architecture of the tool and its utilization by the experiment operators are described in this paper.

Description: At the Paul Scherrer Institute (PSI) in Switzerland, cancer patients are treated with protons. Proton therapy at PSI has a long history and started in the 1980s. More than 30 years later, a new gantry has recently been installed in the existing facility. This new machine has been delivered by an industry partner. A big challenge is the integration of the vendor’s safety system into the existing PSI environment. Different interface standards and the complexity of the system made it necessary to find a technical solution connecting an industry system to the existing PSI infrastructure. A novel very flexible distributed IO system based on field-programmable gate array (FPGA) technology was developed, supporting many different IO interface standards and high-speed communication links connecting the device to a PSI standard versa module eurocard-bus input output controller. This paper summarizes the features of the hardware technology, the FPGA framework with its high-speed communication link protocol, and presents our first measurement results.

Description: Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication.

Description: The bursty many-to-one communication pattern, typical for data acquisition systems, is particularly demanding for commodity TCP/IP and Ethernet technologies. We expand the study of lossless switching in software running on commercial off-the-shelf servers, using the ATLAS experiment as a case study. In this paper, we extend the popular software switch, Open vSwitch, with a dedicated, throughput-oriented buffering mechanism for data acquisition. We compare the performance under heavy congestion on typical Ethernet switches to a commodity server acting as a switch. Our results indicate that software switches with large buffers perform significantly better. Next, we evaluate the scalability of the system when building a larger topology of interconnected software switches, exploiting the integration with software-defined networking technologies. We build an IP-only leaf-spine network consisting of eight software switches running on distinct physical servers as a demonstrator.

Description: HEPS-BPIX is a silicon pixel detector designed for the future large scientific facility, high-energy photon sources (HEPS) in Beijing, China. It is a high frame rate hybrid pixel detector which works in the single-photon-counting mode. High frame rate leads to much higher readout data bandwidth than former systems, which is also the difficulty of the design. Aiming to test and calibrate the pixel detector, a test system based on the National Instruments single-board RIO 9626 and LabVIEW program environment has been designed. A series of tests has been carried out with X-ray machine as well as on the Beijing Synchrotron Radiation Facility 1W2B beamline. The test results show that the threshold uniformity is better than 60 electrons and the equivalent noise charge is less than 120 electrons. Besides, the required highest frame rate of 1.2 kHz has been realized. This paper will elaborate the test system design and present the latest testing results of the HEPS-BPIX system.

Description: The aim of this contribution is to describe our recent development of a novel compact field-programmable gate-array (FPGA)-based data acquisition (DAQ) system for use with multichannel X-ray detectors at synchrotron radiation facilities. The system is designed for time resolved counting of single photons arriving from several—currently 12—independent detector channels simultaneously. Detector signals of at least 2.8 ns duration are latched by asynchronous logic and then synchronized with the system clock of 100 MHz. The incoming signals are subsequently sorted out into 10 000 time-bins where they are counted. This occurs according to the arrival time of photons with respect to the trigger signal. Repeatable mode of triggered operation is used to achieve high statistic of accumulated counts. The time-bin width is adjustable from 10 ns to 1 ms. In addition, a special mode of operation with 2 ns time resolution is provided for two detector channels. The system is implemented in a pocket-size FPGA-based hardware of 10 cm $\times 10$ cm $\times 3$ cm and thus can easily be transported between synchrotron radiation facilities. For setup of operation and data read-out, the hardware is connected via USB interface to a portable control computer. DAQ applications are provided in both LabVIEW and MATLAB environments.

Description: Neutrinos play a fundamental role in the understanding of the origin of ultrahigh-energy cosmic rays. They interact through charged and neutral currents in the atmosphere generating extensive air showers. However, the very low rate of events potentially generated by neutrinos is a significant challenge for detection techniques and requires both sophisticated algorithms and high-resolution hardware. Air showers initiated by protons and muon neutrinos at various altitudes, angles, and energies were simulated in CORSIKA and the Auger OffLine event reconstruction platforms, giving analog-to-digital convertor (ADC) patterns in Auger water Cherenkov detectors on the ground. The proton interaction cross section is high, so proton “old” showers start their development early in the atmosphere. In contrast to this, neutrinos can generate “young” showers deeply in the atmosphere relatively close to the detectors. Differences between “old” proton and “young” neutrino showers are visible in attenuation factors of ADC waveforms. For the separation of “old” proton and “young” neutrino ADC traces, many three-layer artificial neural networks (ANNs) were tested. They were trained in MATLAB (in a dedicated way -only “old” proton and “young” neutrino showers as patterns) by simulated ADC traces according to the Levenberg–Marquardt algorithm. Unexpectedly, the recognition efficiency is found to be almost independent of the size of the networks. The ANN trigger based on a selected 8-6-1 network was tested in the Cyclone V E FPGA 5CEFA9F31I7, the heart of prototype front-end boards developed for testing new algorithms in the Pierre Auger surface detectors.

Description: A novel field-programmable gate array (FPGA)-based online tracking algorithm for helix track reconstruction in a solenoidal field, developed for the Antiproton Annihilations at Darmstadt spectrometer, is described. Employing the straw tube tracker detector with 4636 straw tubes, the algorithm includes a complex track finder and a track fitter. Implemented in VHDL, the algorithm is tested on a Xilinx Virtex-4 FX60 FPGA chip with different types of events, at different event rates. A processing time of $7~\mu \text{s}$ per event for an average of six charged tracks is obtained. The momentum resolution is about 3% (4%) for $p_{t}$ ( $p_{z}$ ) at 1 GeV/c. Comparing with the algorithm running on a CPU chip (single core Intel Xeon E5520 at 2.26 GHz), an improvement of three orders of magnitude in processing time is obtained. The algorithm can handle severe overlapping of events, which are typical for interaction rates above 10 MHz.

Description: The KOTO experiment at J-PARC, Japan, aims to observe the rare neutral kaon decay mode $K_{L}\rightarrow \pi ^{0}\nu \bar {\nu }$ . After the first experimental run in May 2013 at a 24-kW beam power, the KOTO data acquisition (DAQ) system was upgraded in 2015 to provide efficient and reliable data collection at higher beam intensities. Lossless data compression in the analog-to-digital converter modules was implemented to reduce the size of data packets, resulting in a threefold increase in data collection rate. A new software trigger on a 47-node cluster was designed to use Infiniband hardware with message passing interface protocol to establish a mesh network inside the computer clusters for parallel data processing. The upgrade to the KOTO DAQ system was commissioned in 2015 and successfully collected data with a beam intensity of up to 42 kW. In preparation for increasing beam intensities in future runs, the hardware trigger upgrades using the reconfigurable clustering element platform technology are under development.

Description: Radio emission from the extensive air showers (EASs), initiated by ultrahigh-energy cosmic rays, was theoretically suggested over 50 years ago. However, due to technical limitations, successful collection of sufficient statistics can take several years. Nowadays, this detection technique is used in many experiments consisting in studying EAS. One of them is the Auger Engineering Radio Array (AERA), located within the Pierre Auger Observatory. AERA focuses on the radio emission, generated by the electromagnetic part of the shower, mainly in geomagnetic and charge excess processes. The frequency band observed by AERA radio stations is 30–80 MHz. Thus, the frequency range is contaminated by human-made and narrow-band radio frequency interferences (RFIs). Suppression of contaminations is very important to lower the rate of spurious triggers. There are two kinds of digital filters used in AERA radio stations to suppress these contaminations: the fast Fourier transform median filter and four narrow-band IIR-notch filters. Both filters have worked successfully in the field for many years. An adaptive filter based on a least mean squares (LMS) algorithm is a relatively simple finite impulse response (FIR) filter, which can be an alternative for currently used filters. Simulations in MATLAB are very promising and show that the LMS filter can be very efficient in suppressing RFI and only slightly distorts radio signals. The LMS algorithm was implemented into a Cyclone V field programmable gate array for testing the stability, RFI suppression efficiency, and adaptation time to new conditions. First results show that the FIR filter based on the LMS algorithm can be successfully implemented and used in real AERA radio stations.

Description: Micropattern gas detectors (MPGDs) have a wide application in high-energy physics, astrophysics, nuclear physics, medical imaging, and so on. The demand for large area and good spatial resolution requires a large number of channels. The conventional 2-D tracking for MPGDs requires a large number of electronic channels, and in consequence poses a big challenge for the integration, power consumption, cooling, and cost, which has become a problem to the further applications of MPGDs. In this paper, a new tracking method for MPGDs based on 2-D encoded multiplexing readout is presented, which is easily extensible and can significantly reduce the number of electronic readout channels.

Description: A series of techniques is presented that has been developed to optimize the output magnetic field of the feedback control system on the RFX-mod reversed field pinch device. With the aim of minimizing the harmonic distortion and correcting localized error fields, these methods should be lightweight for real-time application and effective in improving the performance of a system that is routinely used for active control of magnetohydrodynamic plasma instabilities. The implementation of simple, linear algebra based, real-time optimization methods will be described along with proof of the beneficial effects sought. The focus of this paper is set on a spurious harmonics reduction technique based on the decoupling of sensors and actuators; a description of its derivation will be given together with the implementation in the control loop. A similar procedure for the compensation of faulted actuators will also be mentioned.

Description: The Indian test facility (INTF) is a negative hydrogen ion-based 100-kV, 60-A, 5-Hz modulated neutral beam injector system having a 3 s on/20 s off duty cycle. The prime objective of the facility is to characterize the ITER diagnostic neutral beam (DNB) with full specifications prior to shipment and installation in ITER. The automated and safe operation of the system will require a reliable and rugged instrumentation and control system that provides control, data acquisition (DAQ), safety, and interlock functions, referred to as INTF-DAQ and control system (DACS). The INTF-DACS has been designed based on the ITER Control, Data Access and Communication (CODAC) architecture and ITER-plant control design handbook guidelines to develop a technical understanding of the CODAC framework to be utilized for the development of plant system instrumentation and control for DNB. The hardware has been selected from the ITER slow-and-fast controller catalog. For high-speed diagnostics, non-National Instruments (NI) high-speed digitizers have been selected. In the area of software, the CODAC core software for control application and NI-LabVIEW for the DAQ application have been finalized. There are around 300 control and 500 acquisition channels consisting of thermal, optical, current, and voltage measurements. The DACS has the mandate to operate INTF for pulselengths up to 3600 s by integrating 14 different plant systems, which includes the power supply plant system under a separate controller. The corresponding development possesses many technical challenges. The estimated file size of a single experimental pulse is in GBs for which the ITER suggested HDF5 format is selected. The timing distribution is another challenge because of the different resolutions required in fast controller, slow controller, and high-speed diagnostics in a distributed area. Long pulse DAQ and monitoring is another challenge. Data exchange across the software platforms, based on Experimental Physics and - ndustrial Control System (EPICS) and LabVIEW, is also required for integration. At present, the control and DAQ hardware have been integrated and the development phase has been initiated on actual hardware platforms. This paper describes the various developmental activities undertaken to solve the technical challenges in the previously mentioned areas and integration of various components of the DACS toward realizing the full-fledged functional INTF DACS.

Description: A future thermonuclear fusion reactor relies on the real-time control of, among others, instabilities and plasma position. At the ISTTOK tokamak, a novel approach of a real-time diagnostic system to control the vertical plasma position (in a 100- $\mu \text{s}$ closed-loop) was implemented by: 1) developing the heavy ion beam diagnostic (HIBD) to perform the position measurement and 2) combining data processing on a field-programmable gate array and Multithreaded Application Real-Time executor software framework. The results of this implementation have demonstrated the successful control of the plasma position using the HIBD. It was proven that the HIBD can be used to measure the ISTTOK vertical plasma position and to provide feedback in real time. In this paper, the overall implementation and integration is described and the experimental results are presented.

Description: The Belle II experiment is the major upgrade of the Belle experiment, which verified Kobayashi–Maskawa mechanism to explain the violation of charge and parity symmetry in the Standard Model. The Belle II experiment will focus on a search for physics beyond the standard model with the upgraded high-luminosity electron-positron collider, SuperKEKB at KEK. The readout subsystem of the Belle II data-acquisition system needs to receive a large amount of data from different front-end electronics (FEEs) of several subdetectors and process and send the data to a high-level trigger system which performs event-rate reduction. The common readout subsystem for the Belle II experiment was developed for all subdetectors except for the innermost pixel detector. The subsystem consists of readout boards with high-speed serial links and readout PC servers. In the Belle II experiment, once event building is performed, events are distributed over processor nodes, which can be scaled up rather easily during the experimental period. For the readout subsystem before the event builder, however, that event-based parallel processing is impossible. Therefore, the performance of the readout subsystem should be checked carefully before the experiment starts. To check the performance of the readout subsystem, we performed a stress test with dummy data produced by field-programmable gate array on FEEs and readout boards. We used one unit of the readout subsystem for the test, which consists of one PC server and several readout boards. In this test, the system achieved to handle the target event rate of 30 kHz with loss of very few events. The readout test with some of the Belle II subdetectors was also performed in cosmic-ray tests measurements. The readout subsystem worked stably and the basic functionality was tested with real data from the subdetectors.

Description: A cognitive image processing implementation for pattern-matching execution is proposed in this paper. It is based on the learning process of the human vision as an edge-enhancing filter for medical images. We set up an experiment to test its impact on the performance of decision-making algorithm working on brain magnetic resonance data. The execution times of similar filters can become unpractical on real 3-D or higher dimensional data, if implemented on a CPU. An innovative and high-performance embedded system for real-time pattern matching was developed. The design uses field-programmable gate arrays and the powerful associative memory chip (an ASIC) to achieve real-time performance and requires a training phase and a data acquisition phase. It is a very compact implementation that improves execution time $\times 1000$ for the training phase and $\times 100$ for the data acquisition phase for 2-D black and white images compared to a last generation i7 CPU. The implementation of this edge-enhancing filter is expected to positively impact on medical devices for real-time diagnosis (e.g., diagnostic ultrasound) and for image processing steps in medical image analysis where computing power is a limiting factor.

Description: Aiming to high sensitivity and wide spectrum of cosmic ray detection, the 1 km 2 complex array of large high altitude air shower observatory (LHAASO-KM2A) project consists of over 7000 detectors of different types. To reconstruct the air shower events with high angular resolution, timestamps of all detector electronics and digitizers should be aligned better than 500 ps RMS. White Rabbit (WR) technology, a fully deterministic Ethernet-based network with subnanosecond synchronization accuracy and picoseconds precision, is applied to build the dedicated data and timing network. To guarantee the overall synchronization precision, individual calibration of each WR node is essential to compensate device deviation. This paper talks about autocalibration procedure of all nodes in the LHAASO-KM2A WR network using the portable calibration node (PCN). Usage of the PCN in deploying the detectors array and validating synchronization performance of the WR network is also discussed.

Description: This paper presents the integration of an acquisition and computing unit capable of acquiring and processing fast magnetic signals in real time in the control system of the tokamak à configuration variabile tokamak. All aspects of system integration and testing are reported, leading to testing of the system on plasma discharges. An example of a real-time analysis algorithm designed for detecting and classifying neoclassical tearing modes plasma instabilities is also described.

Description: For the 2016 physics data runs, the L1 trigger system of the compact muon solenoid (CMS) experiment underwent a major upgrade to cope with the increasing instantaneous luminosity of the CERN LHC whilst maintaining a high event selection efficiency for the CMS physics program. Most subsystem specific trigger processor boards were replaced with powerful general purpose processor boards, conforming to the MicroTCA standard, whose tasks are performed by firmware on an field-programmable gate array of the Xilinx Virtex 7 family. Furthermore, the muon trigger system moved from a subsystem centered approach, where each of the three muon detector systems provides muon candidates to the global muon trigger (GMT), to a region-based system, where muon track finders (TFs) combine information from the subsystems to generate muon candidates in three detector regions that are then sent to the upgraded GMT. The upgraded GMT receives up to 108 muons from the processors of the muon TFs in the barrel, overlap, and endcap detector regions. The muons are sorted in two steps and duplicates are identified for removal. The first step treats muons from different processors of a TF in one detector region. Muons from TFs in different detector regions are compared in the second step. An isolation variable is calculated, using energy sums from the calorimeter trigger and added to each of the best eight muons before they are sent to the upgraded global trigger (GT) where the final trigger decision is made. The upgraded GMT algorithm is implemented on a general purpose processor board that uses optical links at 10 Gb/s to receive the input data from the muon TFs and the calorimeter energy sums, and to send the selected muon candidates to the upgraded GT.

Description: The operation of the compact muon solenoid drift tubes (DTs) muon detectors at the high-luminosity large hadron collider will be possible only with an upgrade of the current readout and trigger electronics, which are based on very old technology and directly exposed to radiation, hence particularly sensitive to aging. A new level 1 trigger primitive generator, based on the use of an original compact Hough transform (CHT) algorithm, is being designed with the goal of its implementation in the state-of-the-art field programmabla gate array (FPGA) devices. The algorithm can identify the muon track segment parameters and must be combined with a majority mean-timer in order to assign the muon to its parent bunch crossing. The algorithm is expected to be deployed on FPGAs and has a few $\mu \text{s}$ latency for decision taking, with efficiency and resolution equal or higher with respect to the ones provided by the currently running algorithm. The major challenges are parallelization of the algorithm, fast readout of the CHT parameter matrix, the capability of handling data from a large array of DTs in the minimal number of FPGAs, and coping with the latency requirements. These issues will be addressed proposing constructive solutions.

Description: The Large Hadron Collider Beauty experiment (LHCb) experiment is preparing a major upgrade resulting in the need for a high-end network for the data acquisition system. Its capacity will grow up to a target speed of 40 Tb/s, aggregated by 500 nodes. This can only be achieved reasonably by using links that are capable of coping with 100-Gb/s line rates. The constantly increasing need for more and more bandwidth has initiated the development of commercial 100-Gb/s networks. There are three candidates on the horizon that need to be considered: Intel Omni-Path, 100-G Ethernet, and EDR InfiniBand. We present test results with such links using both standard benchmarks (e.g., iperf) and a custom benchmark called Data AcQquisition (DAQ) Protocol Independent Performance Evaluator (DAQPIPE). With DAQPIPE, we mainly evaluate the ability to exploit the targeted network for a kind of all-to-all communication pattern. The key benefit of these measurements is that it helps us to tune our benchmark and improves our understanding of the relevant parameters. It will now permit us to prepare and motivate some upcoming tests at scale on existing supercomputers offering the targeted hardware.

Description: To increase the event yield, the LHCb experiment will undergo a major detector upgrade planned during the second long shutdown of the Large Hadron Collider (2019–2020). The new data acquisition has to process the whole 40-MHz input event rate, relying only on the large-scale computing farm implementation of the high-level trigger. Event fragments will be forwarded at 40 MHz from the detector front-end electronics to the event builder (EB), through optical links and peripheral component interconnect express cards. The EB farm, of about 500 computers, shall provide an aggregated throughput of 32 Tb/s. To reach the required EB performance, we are testing various interconnect technologies and network protocols on large-scale computing clusters. For this purpose, we have developed an EB software evaluator. We report here about the results of the measurements performed on high-performance computing facilities to test throughput and scalability.

Description: Describes the above-named upcoming conference event. May include topics to be covered or calls for papers.

Description: In this paper, we investigated the hardware implementation of two feedforward neural networks (NNs) using a field-programmable gate array (FPGA), then used the networks for alpha–gamma discrimination in barium fluoride (BaF 2 ). The BaF 2 detector output was sampled using a 1-GSPS ADC, and then we extracted six information of the pulses in FPGA as the input features to the NNs. The performance of this method turned out very good, the false alarm rate of the networks was less than 0.3%. Besides, dead time of the networks was less than 820 ns. Low logic occupancy is also discussed.

Description: ITER control system model (ICM) is a currently developed simulation platform for control, data access, and communication (CODAC), which is a central control system responsible for integrating and controlling all plant systems of ITER. ICM is a large-scale implementation of CODAC that follows hardware and software standards but does not have any interfaces to other physical components of ITER. ICM will serve as an excellent test environment for performance and scalability of upcoming plant system modules and new releases of CODAC software. This paper focuses on performance and reliability of the real-time components of ICM, consisting of eight fast controllers connected over physical networks and their dedicated high-performance switches. Two crucial ITER requirements are satisfied with 12.4- $\mu \text{s}$ 1-kB packet transfer latency and system clock synchronization with a standard deviation as low as 16.7 ns. This performance evaluation is required for demonstrating the reliability of the CODAC infrastructure and gathering important data for considering future plant system modules.

Description: These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal.

Description: Modern digital low level radio frequency (RF) control systems used to stabilize the accelerating field in facilities, such as free electron laser in Hamburg or the European X-ray free electron laser, are based on the field programmable gate array (FPGA) technology. Presently, these accelerator facilities are operated with pulsed RF. In the future, these facilities will operate with the continuous wave (CW), which requires significant modifications on the real-time feedbacks realized within the FPGA. For example, higher loaded quality factor of the superconducting RF cavities operated in the CW mode requires sophisticated resonance control methods. However, iterative learning techniques widely used for machines operated in pulsed mode are not applicable for the CW. In addition, the mechanical characteristic of the cavities now have a much more important impact on the choice of the feedback scheme. To overcome the limitations of classical proportional–integral controllers, a novel real-time adaptive feed-forward algorithm is implemented in the FPGA. Also, the high power RF amplifier, which is an inductive output tube (IOT) for CW operation instead of a klystron for the pulsed mode, has a major impact on the design and implementation of the firmware for regulation. In this paper, we report on our successful approach to control the multicavity vector sum with an ultrahigh precision (amplitude error <0.01% rms and phase stability <0.02° rms), using a single IOT source and the individual resonance control through piezoactuators. Performance measurements of the proposed solution were conducted at the cryomodule test bench facility.