Development and Testing of Gallium Arsenide Photoconductive Detectors for Ultra Fast, High Dose Rate Pulsed Electron and Bremsstrahlung Radiation Measurements

Journal Article · Tue Mar 10 00:00:00 EDT 2009 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3120099· OSTI ID:21289596

Kharashvili, George; Makarashvili, Vakhtang; Mitchell, Marc; Beezhold, Wendland; Spaulding, Randy; Wells, Douglas; Gesell, Thomas ^[1]; Wingert, Wayne ^[2]

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1. Department of Physics, Idaho State University, Campus box 8106, Pocatello, Idaho 83209 (United States)
2. Department of Physics, University of Utah, 201 Presidents Circle, Salt Lake City, Utah 84112 (United States)

Real time radiation dose measurements are challenging in high dose rate environments such as those used for testing electronic devices or biological agents. Dosimetry needs in pulsed reactor fields and particle accelerator facilities require development of dosimeters with fast (10 s of picoseconds) response to pulsed radiation, linear response over a wide range of dose rates (up to 10{sup 11} Gy/s), high resistance to radiation damage, and successful operation in mixed gamma and neutron environments. Gallium arsenide photoconductive detectors (GaAs PCD) have been shown to exhibit many of these desirable characteristics, especially fast time response. Less than 50 ps time resolution has been demonstrated when previously irradiated by fission neutrons. We have conducted a study of the response-time dependence on neutron fluence, starting with fluences at {approx}10{sup 14} n/cm{sup 2}. A 23-MeV electron beam was used to produce photoneutrons in a tungsten target for irradiation of a GaAs wafer from which PCDs were made. The process was modeled using MCNPX computer code and the simulation results were compared to the experimental measurements. GaAs PCDs were fabricated from both neutron-irradiated and non-irradiated GaAs samples. The results of the preliminary tests of these devices in accelerator-produced pulses of electron and bremsstrahlung radiation of various energies (13 to 35 MeV) and pulse lengths (100 ps to 4 {mu}s) are presented together with an overview of the future plans of continuing GaAs PCD research at Idaho State University.

• OSTI ID: 21289596
• Journal Information: AIP Conference Proceedings, Vol. 1099, Issue 1; Conference: CAARI 2008: 12. international conference on application of accelerators in research and industry, Fort Worth, TX (United States), 10-15 Aug 2008; Other Information: DOI: 10.1063/1.3120099; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
BREMSSTRAHLUNG
COMPUTERIZED SIMULATION
ELECTRON BEAMS
GALLIUM ARSENIDES
M CODES
MEV RANGE
MONTE CARLO METHOD
NEUTRON FLUENCE
PHOTODETECTORS
PHOTONEUTRONS
PHYSICAL RADIATION EFFECTS
PULSED IRRADIATION
RADIATION DETECTION
RADIATION DETECTORS
TESTING
TIME RESOLUTION