ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Collection
Keywords
Publisher
Years
  • 1
    facet.materialart.
    Unknown
    Study of High-Beta Magnetohydrodynamic Modes and Fast-Ion Losses in PDX. (1983)
    American Physical Society
    Details
    Publication Date: 1983-11-14
    Print ISSN: 0031-9007
    Electronic ISSN: 1079-7114
    Topics: Physics
    Published by American Physical Society
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    Electronic Resource
    Electronic Resource
    Distinction between DD and DT neutrons in the TFTR neutron collimator (1997)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 68 (1997), S. 1268-1272 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A difficult part of the analysis of the neutron collimator data is the distinction between contributions from DD and DT neutrons. This is important for the majority of TFTR discharges, which use neutral deuterium heating beams and relatively small amounts of tritium. At present, the DT-neutron contribution is determined from a comparison of the chord-integrated neutron collimator data with measurements of the DT-neutron source strength from general wide-angle detectors, using an iterative computational method. A more satisfactory solution should be obtained with detectors that measure the contributions from DD and DT neutrons, and gamma radiation, directly. Pulse-shaping techniques are insufficient, since the detectors in the neutron collimator are operated in current mode. The presently used data analysis is described and the concept of a new multilayered plastic detector that makes use of the differences in the attenuation of the various radiation components is presented. The dimensions of the detector are based on calculations of the attenuation for the expected neutron energy spectrum. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1147898
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Distinction between DD and DT neutrons in the TFTR neutron collimator (abstract) : Proceedings of the eleventh topical conference on high temperature plasma diagnostics (1997)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 68 (1997), S. 552-552 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A difficult part of the analysis of the neutron collimator data is the distinction between contributions from DD and DT neutrons. This is important for the majority of TFTR discharges, which use neutral deuterium heating beams and relatively small amounts of tritium. At present, the DT-neutron contribution is determined from a comparison of the chord-integrated neutron collimator data with measurements of the DT-neutron source strength from general wide-angle detectors, using an iterative computational method. A more satisfactory solution should be obtained with detectors that measure the contributions from DD and DT neutrons, and gamma radiation, directly. Pulse-shaping techniques are insufficient, since the detectors in the neutron collimator are operated in current mode. The presently used data analysis is described and the concept of a new multilayered plastic detector that makes use of the differences in the attenuation of the various radiation components is presented. The dimensions of the detector are based on calculations of the attenuation for the expected neutron energy spectrum. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1147650
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Analysis of nuclear-radiation-induced noise in spectroscopic and x-ray diagnostics during high power deuterium–tritium experiments on the tokamak fusion test reactor : Proceedings of the tenth topical conference on high temperature plasma diagnostics (1995)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 913-915 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Intense fluxes of 14-MeV neutrons from deuterium–tritium (DT) fusion reaction in TFTR resulted in significantly enhanced background noise levels and reduced quality of data from the shielded UV (SPRED) and visible (VIPS) grating spectrometers and the x-ray imaging system (XIS) camera. Both enhanced background levels, attributed to gamma rays and small angle neutron scattering, and large spikes, attributed to nuclear reactions in the silicon detectors, were observed. Both the enhanced background and the frequency of spikes were higher, on a per neutron basis, and the spike amplitudes were higher for DT than for DD operation. The VIPS shield reduced noise by 1/100 for DD radiation; the noise per DT neutron was 4 times higher than per DD neutron. The SPRED detector shield reduction factor was 1/12 in DD; extension of the shield around the vacuum chamber resulted in another factor of 1/5.5 reduction for DT plasmas. Spikes with amplitude up to 10 MeV were observed in the XIS detectors. The shielding effectiveness agrees with predictions. The spike heights are consistent with (n,p) and (n,α) reactions in the silicon detectors. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1146203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Imaging x-ray crystal spectrometers for the National Spherical Torus Experiment : Proceedings of the 12th topical conference on high temperature plasma diagnostics (1999)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 70 (1999), S. 292-295 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A new type of high-resolution x-ray imaging crystal spectrometers is described for implementation on the National Spherical Torus Experiment (NSTX) to provide spatially and temporally resolved data on the ion temperature, toroidal and poloidal plasma rotation, electron temperature, impurity ion-charge state distributions, and impurity transport. These data are derived from observations of the satellite spectra of heliumlike argon, Ar XVII, which is the dominant charge state for electron temperatures in the range from 0.4 to 3.0 keV and which is accessible to NSTX. Experiments at the Torus Experiment for Technology Oriented Research (TEXTOR) demonstrate that a throughput of 2×105 photons/s (corresponding to the count-rate limit of the present detectors) can easily be obtained with small, nonperturbing argon gas puffs of less than 1×10−3 Torr l/s, so that it is possible to record spectra with a small statistical error and a good time resolution (typically 50 and 1 ms in some cases). Employing a novel design, which is based on the imaging properties of spherically bent crystals, the spectrometers will provide spectrally and spatially resolved images of the plasma for all experimental conditions, which include ohmically heated discharges as well as plasmas with rf and neutral-beam heating. The conceptual design, experimental results on the focusing properties, and relevant spectral data from TEXTOR are presented. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1149344
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    High speed tangential soft x-ray camera for the study of magnetohydrodynamics instabilities : Proceedings of the 12th topical conference on high temperature plasma diagnostics (1999)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 70 (1999), S. 599-602 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A fast camera system is being prepared for the TEXTOR tokamak for the investigation of magnetohydrodynamics (MHD) instabilities. The camera will consist of a scintillator screen for conversion of x rays into visible light, a fiberoptic cable for transport of the visible images out of the Textor magnetic field, an electrostatic image converter for amplification and demagnification of the images, and a fast charge-coupled device (CCD) camera for capturing and storing the image data. The purpose of our camera is two-dimensional imaging of magnetic islands and the structure of MHD instabilities. In order to increase the signal intensity and simultaneously reduce statistical noise, we maximize the diameter of the scintillator screen to 100 mm. For good time response, we use fast scintillators and phosphors, and plan to employ a 1 MHz framing CCD camera. MHD events having an amplitude larger than 1% can be observed with a time resolution of 100 kHz and a spatial resolution of 3 cm. In the future, the camera will be used on the Large Helical Device in Japan. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1149382
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Recent expansion of the TFTR multichannel neutron collimator : Proceedings of the eleventh topical conference on high temperature plasma diagnostics (1997)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 68 (1997), S. 544-547 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Radial neutron emission profiles from TFTR DT plasmas are generally narrow and highly peaked. In the past, the neutron profile monitor provided inadequate coverage of the plasma core for these peaked profiles. Four new sight lines were added to improve the view in the central region and better evaluate parameters such as global neutron yields and neutron peakedness and to localize neutron MHD activity. The new sightlines utilize plastic scintillators instead of the original ZnS based NE451 detectors. These new detectors have larger volumes and increased solid angles as compared to the NE451 detectors in order to increase the incident neutron flux, in order to reduce statistical "shot noise" on the signal traces and improve the frequency response. The increased detection capabilities along with recent upgrades in the fast amplifiers and wave form digitizers have extended the frequency response to 〉50 kHz which allows the study of high frequency MHD activity. Data from DT plasmas illustrating the enhanced spatial and temporal resolution with the new channels are presented. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1147648
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Calibration issues of the Tokamak Fusion Test Reactor multichannel neutron collimator : Proceedings of the eleventh topical conference on high temperature plasma diagnostics (1997)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 68 (1997), S. 548-551 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The calibration procedures for the detectors in the neutron collimator are reviewed. The absolute calibration was performed for the NE451 detectors, in situ, by moving a DT neutron generator in the Tokamak Fusion Test Reactor (TFTR) vacuum vessel across each sight line. This calibration was transferred to other detectors in the same channel. Four new sight lines have been installed at a different toroidal location, which view the plasma through the vacuum vessel port cover rather than through thinned windows. The new detectors are cross calibrated to the NE451 detectors with a "jog shot" procedure, where the plasma is quickly shifted in major radius over a distance of 30 cm. The jog shot procedure shows that scattered neutrons account approximately for 30% of the signal of the new central channels. Corrections for detector nonlinearity are discussed. The neutron source strength from the collimator agrees within 10% with the source strength from global neutron monitors in the TFTR test cell. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1147649
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Numerical studies of the imaging properties of doubly focussing crystals and their application to ITER : Proceedings of the tenth topical conference on high temperature plasma diagnostics (1995)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 530-532 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Line brightness calculations for the parameters at the International Thermonuclear Experimental Reactor (ITER) and results from recent experiments on the Tokamak Fusion Test Reactor (TFTR) indicate that time-resolved measurements of the central ion temperature and other central plasma parameters should be feasible on ITER with nonperturbing amounts of krypton. Since the measurements will have to be performed in the presence of high fluxes of 14-MeV neutrons from DT-fusion reactions, the size of windows, apertures and x-ray detectors must be as small as possible. Under these conditions, the use of doubly focussing crystals can significantly enhance the signal-to-noise ratio. This paper describes numerical studies of the focussing properties of spherically bent crystals and their application to ITER. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1146341
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    ITER x-ray diagnostic studies : Proceedings of the 9th topical conference on high temperature plasma diagnostics (1992)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 63 (1992), S. 5032-5034 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Present-day tokamak x-ray imaging (XIS) and pulse height analysis (PHA) diagnostics will require special shielding and x-ray optics to permit use on fusion reactors without prohibitive noise and detector damage from neutrons and gamma rays; x-ray curved-crystal spectrometers (XCS) may work with extensive shielding and collimation, but radiation damage of crystals and attainment of adequate impurity concentrations for ion-temperature measurement are concerns. We consider the use of one or more reflections at grazing incidence from x-ray mirrors or from Bragg layered synthetic microstructures (LSM) to decouple the x-ray diagnostic from the direct fusion neutron beam. We present calculations of expected x-ray line brightnesses from ITER and total instrument throughput. We also consider the use of hollow glass capillaries embedded in radiation shields to precede the XIS detector and reduce the ratio of neutron plus gamma radiation to x rays by a factor of ∼0.01 or better. Compatibility of capillary schemes with the PHA and XCS are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1143483
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...