skip to main content

Title: Conceptual design of the gamma-to-electron magnetic spectrometer for the National Ignition Facility

The Gamma-to-Electron Magnetic Spectrometer (GEMS) diagnostic is designed to measure the prompt γ-ray energy spectrum during high yield deuterium-tritium (DT) implosions at the National Ignition Facility (NIF). The prompt γ-ray spectrum will provide “burn-averaged” observables, including total DT fusion yield, total areal density (ρR), ablator ρR, and fuel ρR. These burn-averaged observables are unique because they are essentially averaged over 4π, providing a global reference for the line-of-sight-specific measurements typical of x-ray and neutron diagnostics. The GEMS conceptual design meets the physics-based requirements: ΔE/E = 3%–5% can be achieved in the range of 2–25 MeV γ-ray energy. Minimum DT neutron yields required for 15% measurement uncertainty at low-resolution mode are: 5 × 10{sup 14} DT-n for ablator ρR (at 0.2 g/cm{sup 2}); 2 × 10{sup 15} DT-n for total DT yield (at 4.2 × 10{sup −5} γ/n); and 1 × 10{sup 16} DT-n for fuel ρR (at 1 g/cm{sup 2})
Authors:
; ; ; ; ; ; ;  [1] ; ; ;  [2] ;  [3] ;  [4]
  1. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
  2. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
  3. General Atomics, San Diego, California 92186 (United States)
  4. National Security Technologies, Special Technologies Laboratory, Santa Barbara, California 93111 (United States)
Publication Date:
OSTI Identifier:
22303709
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 85; Journal Issue: 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; DEUTERIUM; D-T OPERATION; ELECTRONS; ENERGY SPECTRA; FUSION YIELD; GAMMA RADIATION; IMPLOSIONS; MAGNETIC SPECTROMETERS; MEV RANGE; NEUTRONS; RESOLUTION; TRITIUM; US NATIONAL IGNITION FACILITY