Gamma-to-electron magnetic spectrometer (GEMS): An energy-resolved {gamma}-ray diagnostic for the National Ignition Facility

Journal Article · Mon Oct 15 00:00:00 EDT 2012 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4738650· OSTI ID:22093807

Kim, Y.; Herrmann, H. W.; Mack, J. M.; Young, C. S.; Barlow, D. B.; Schillig, J. B.; Sims, Jr., J. R.; Lopez, F. E.; Mares, D.; Oertel, J. A.; Hayes-Sterbenz, A. C. ^[1]; Hilsabeck, T. J.; Wu, W. ^[2]; Moy, K. ^[3]; Stoeffl, W. ^[4]

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1. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2. General Atomics, PO Box 85608, San Diego, California 92186 (United States)
3. National Security Technologies, Special Technologies Laboratory, Santa Barbara, California 93111 (United States)
4. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

The gamma-to-electron magnetic spectrometer, having better than 5% energy resolution, is proposed to resolve {gamma}-rays in the range of E{sub o}{+-} 20% in single shot, where E{sub o} is the central energy and is tunable from 2 to 25 MeV. Gamma-rays from inertial confinement fusion implosions interact with a thin Compton converter (e.g., beryllium) located at approximately 300 cm from the target chamber center (TCC). Scattered electrons out of the Compton converter enter an electromagnet placed outside the NIF chamber (approximately 600 cm from TCC) where energy selection takes place. The electromagnet provides tunable E{sub o} over a broad range in a compact manner. Energy resolved electrons are measured by an array of quartz Cherenkov converters coupled to photomultipliers. Given 100 detectable electrons in the energy bins of interest, 3 Multiplication-Sign 10{sup 14} minimum deuterium/tritium (DT) neutrons will be required to measure the 4.44 MeV {sup 12}C {gamma}-rays assuming 200 mg/cm{sup 2} plastic ablator areal density and 3 Multiplication-Sign 10{sup 15} minimum DT neutrons to measure the 16.75 MeV DT {gamma}-ray line.

• OSTI ID: 22093807
• Journal Information: Review of Scientific Instruments, Vol. 83, Issue 10; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
BERYLLIUM
CARBON 12
COMPTON EFFECT
ELECTROMAGNETS
ELECTRON SPECTROMETERS
ENERGY RESOLUTION
GAMMA RADIATION
GAMMA SPECTROMETERS
INERTIAL CONFINEMENT
MAGNETIC SPECTROMETERS
MEV RANGE 10-100
NEUTRONS
PHOTOMULTIPLIERS
QUARTZ
TARGET CHAMBERS
US NATIONAL IGNITION FACILITY