Photocurrent from Single Collision 14 MeV Neutrons in GaN and GaAs

Journal Article · 05 November 2019 · IEEE Transactions on Nuclear Science

DOI: https://doi.org/10.1109/TNS.2019.2949720 · OSTI ID:1574699

Jasica, Matthew J. ^[1]; Wampler, William R. ^[1]; Vizkelethy, Gyorgy ^[1]; Hehr, Brian D. ^[1]; Bielejec, Edward S. ^[1]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Accurate predictions of device performance in 14 MeV neutron environments relies upon understanding the recoil cascades that may be produced. Recoils from 14 MeV neutrons impinging on both gallium nitride (GaN) and gallium arsenide (GaAs) devices were modeled and compared to the recoil spectra of devices exposed to 14 MeV neutrons. Recoil spectra were generated using nuclear reaction modeling programs and converted into an ionizing energy loss (IEL) spectrum. We measured the recoil IEL spectra by capturing the photocurrent pulses produced by single neutron interactions with the device. Good agreement, with a factor of two, was found between the model and experiment under strongly-depleted conditions. However, this range of agreement between model and experiment decreased significantly when the bias was removed, indicating partial energy deposition due to cascades that escape the active volume of the device not captured by the model. Consistent event rates across multiple detectors confirm the reliability of our neutron recoil detection method.

• Research Organization: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Security
• Grant/Contract Number: AC04-94AL85000
• OSTI ID: 1574699
• Report Number(s): SAND-2019-11380J; 679523; TRN: US2001202
• Journal Information: IEEE Transactions on Nuclear Science, Vol. 67, Issue 1; ISSN 0018-9499
• Publisher: IEEECopyright Statement
• Country of Publication: United States
• Language: English