Cherenkov radiation conversion and collection considerations for a gamma bang time/reaction history diagnostic for the NIF

Journal Article · Wed Oct 15 04:00:00 EDT 2008 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.2979868· OSTI ID:21266520

Herrmann, Hans W; Mack, Joseph M; Young, Carlton S ^[1]; Malone, Robert M ^[2]; Stoeffl, Wolfgang ^[3]; Horsfield, Colin J ^[4]

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1. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2. National Security Technologies, Los Alamos Operations, Los Alamos, New Mexico 87544 (United States)
3. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
4. Atomic Weapons Establishment, Aldermaston (United Kingdom)

Bang time and reaction history measurements are fundamental components of diagnosing inertial confinement fusion (ICF) implosions and will be essential contributors to diagnosing attempts at ignition on the National Ignition Facility (NIF). Fusion gammas provide a direct measure of fusion interaction rate without being compromised by Doppler spreading. Gamma-based gas Cherenkov detectors that convert fusion gamma rays to optical Cherenkov photons for collection by fast recording systems have been developed and fielded at Omega. These systems have established their usefulness in illuminating ICF physics in several experimental campaigns. Bang time precision better than 25 ps has been demonstrated, well below the 50 ps accuracy requirement defined by the NIF system design requirements. A comprehensive, validated numerical study of candidate systems is providing essential information needed to make a down selection based on optimization of sensitivity, bandwidth, dynamic range, cost, and NIF logistics. This paper presents basic design considerations arising from the two-step conversion process from {gamma} rays to relativistic electrons to UV/visible Cherenkov radiation.

• OSTI ID: 21266520
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 10 Vol. 79; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ACCURACY
CHERENKOV COUNTERS
CHERENKOV RADIATION
DESIGN
ELECTRONS
GAMMA RADIATION
GAS SCINTILLATION DETECTORS
INERTIAL CONFINEMENT
NUMERICAL ANALYSIS
PLASMA
PLASMA PRODUCTION
RECORDING SYSTEMS
RELATIVISTIC RANGE
SENSITIVITY
THERMONUCLEAR REACTORS
US NATIONAL IGNITION FACILITY