Characterization of the Mercury pulsed power x-ray source spectrum using multichannel density aerogel Cherenkov detectors

Journal Article · 04 October 2018 · Review of Scientific Instruments

DOI: https://doi.org/10.1063/1.5038745 · OSTI ID:1479994

Meaney, K. D.  ^[1]; Kim, Y. ^[1]; Herrmann, H. W. ^[1]; Young, C. Y. ^[1]; Archuleta, T. A. ^[1]; Hamilton, C. E. ^[1]; Duke, D. L. ^[1]; Haines, T. J. ^[1]; Corredor, A. C. ^[2]; Green, J. A.  ^[2]; Fegenbush, L. ^[2]; Kaufman, M. I. ^[2]; Malone, R. M.  ^[2]; Baker, S. A. ^[2]; Richardson, S.  ^[3]; Zier, J. ^[3]; Engelbrecht, J. ^[3]; Culver, A. ^[3]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Mission Support and Test Services, Las Vegas, NV (United States)
3. Naval Research Lab. (NRL), Washington, DC (United States)

The Aerogel Cherenkov Detector for Cygnus (ACD/C) is a time-dependent, x-ray spectral detector that uses SiO₂ aerogels spanning an index of refraction (n = 1.02–1.07) corresponding to a 1.1–2.3 MeV x-ray energy threshold. The ACD/C was developed for pulsed power x-ray sources like Cygnus located at the Nevada National Site and Mercury located at the Naval Research Laboratory (NRL). Aerogels sit between the measurement capabilities of gas (>2 MeV) and solids such as fused silica (>0.3 MeV). The detector uses an aluminum converter to Compton scatter incoming x-rays and create relativistic electrons, which produce Cherenkov light in an aerogel or a fused silica medium. The ACD/C was fielded at the NRL when Mercury was tuned to produce up to 4.8 MeV endpoint bremsstrahlung. Despite a high radiation and electromagnetic interference background, the ACD/C was able to achieve high signal over noise across five aerogel densities and fused silica, including a signal to noise for a 1.1 MeV aerogel threshold. Previous experiments at Cygnus observed a signal that was comparable to the noise (1×) at the same threshold. The ACD/C observed time-resolved rise and fall times for different energy thresholds of the photon spectrum. Finally, Monte Carlo simulations of the ACD/C’s aerogel response curves were folded with a simulation of Mercury’s photon energy spectrum and agree within the error to the observed result.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC52-06NA25396; NA0003624
• OSTI ID: 1479994
• Alternate ID(s): OSTI ID: 1476132
• Report Number(s): LA-UR-18-23983
• Journal Information: Review of Scientific Instruments, Vol. 89, Issue 10; ISSN 0034-6748
• Publisher: American Institute of Physics (AIP)Copyright Statement
• Country of Publication: United States
• Language: English