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Title: Diagnosing inertial confinement fusion gamma ray physics (invited)

Journal Article · · Review of Scientific Instruments
DOI:https://doi.org/10.1063/1.3495770· OSTI ID:22058656
; ; ; ; ; ;  [1]; ;  [2]; ;  [3];  [4];  [5]
  1. Los Alamos National Laboratory, P.O. Box 1663, M/S E526, Los Alamos, New Mexico 87545 (United States)
  2. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
  3. Atomic Weapons Establishment, Aldermaston, Reading RG7 4PR (United Kingdom)
  4. Special Technologies Laboratory, NSTec, Santa Barbara, California 93111 (United States)
  5. Livermore Operations, NSTec, Livermore, California 94550 (United States)

The gamma reaction history (GRH) diagnostic is a multichannel, time-resolved, energy-thresholded {gamma}-ray spectrometer that provides a high-bandwidth, direct-measurement of fusion reaction history in inertial confinement fusion implosion experiments. 16.75 MeV deuterium+tritium (DT) fusion {gamma}-rays, with a branching ratio of the order of 10{sup -5}{gamma}/(14 MeV n), are detected to determine fundamental burn parameters, such as nuclear bang time and burn width, critical to achieving ignition at the National Ignition Facility. During the tritium/hydrogen/deuterium ignition tuning campaign, an additional {gamma}-ray line at 19.8 MeV, produced by hydrogen+tritium fusion with a branching ratio of unity, will increase the available {gamma}-ray signal and may allow measurement of reacting fuel composition or ion temperature. Ablator areal density measurements with the GRH are also made possible by detection of 4.43 MeV {gamma}-rays produced by inelastic scatter of DT fusion neutrons on {sup 12}C nuclei in the ablating plastic capsule material.

OSTI ID:
22058656
Journal Information:
Review of Scientific Instruments, Vol. 81, Issue 10; Other Information: (c) 2010 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
Country of Publication:
United States
Language:
English