The coincidence counting technique for orders of magnitude background reduction in data obtained with the magnetic recoil spectrometer at OMEGA and the NIF

Journal Article · Fri Jul 15 04:00:00 EDT 2011 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.3605483· OSTI ID:22075521

Casey, D T; Frenje, J A; Seguin, F H; Li, C K; Rosenberg, M J; Rinderknecht, H; Manuel, M J -E; Gatu Johnson, M; Schaeffer, J C; Frankel, R; Sinenian, N; Childs, R A; Petrasso, R D ^[1]; Glebov, V Yu; Sangster, T C; Burke, M; Roberts, S ^[2]

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1. Plasma Science and Fusion Center, MIT, Cambridge, Massachusetts 02139 (United States)
2. Laboratory for Laser Energetics, UR, Rochester, New York 14623 (United States)

A magnetic recoil spectrometer (MRS) has been built and successfully used at OMEGA for measurements of down-scattered neutrons (DS-n), from which an areal density in both warm-capsule and cryogenic-DT implosions have been inferred. Another MRS is currently being commissioned on the National Ignition Facility (NIF) for diagnosing low-yield tritium-hydrogen-deuterium implosions and high-yield DT implosions. As CR-39 detectors are used in the MRS, the principal sources of background are neutron-induced tracks and intrinsic tracks (defects in the CR-39). The coincidence counting technique was developed to reduce these types of background tracks to the required level for the DS-n measurements at OMEGA and the NIF. Using this technique, it has been demonstrated that the number of background tracks is reduced by a couple of orders of magnitude, which exceeds the requirement for the DS-n measurements at both facilities.

• OSTI ID: 22075521
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 7 Vol. 82; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COINCIDENCE METHODS
DEUTERIUM
HYDROGEN
IMPLOSIONS
NEUTRONS
OMEGA FACILITY
PARTICLE TRACKS
PROTON RECOIL DETECTORS
SPECTROMETERS
TRITIUM
US NATIONAL IGNITION FACILITY