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Title: Signal and background considerations for the MRSt on the National Ignition Facility (NIF)

A Magnetic Recoil Spectrometer (MRSt) has been conceptually designed for time-resolved measurements of the neutron spectrum at the National Ignition Facility. Using the MRSt, the goals are to measure the time-evolution of the spectrum with a time resolution of ~20-ps and absolute accuracy better than 5%. To meet these goals, a detailed understanding and optimization of the signal and background characteristics are required. Through ion-optics, MCNP simulations, and detector-response calculations, we demonstrate that the goals and a signal-to background >5-10 for the down-scattered neutron measurement are met if the background, consisting of ambient neutrons and gammas, at the MRSt is reduced 50-100 times.
 [1] ;  [1] ;  [2] ;  [3] ;  [3] ;  [1] ;  [2] ;  [1] ;  [1] ;  [1]
  1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
  2. General Atomics, San Diego, CA (United States)
  3. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
AC52-07NA27344; NA0002949; NA0001857
Accepted Manuscript
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 87; Journal Issue: 11; Conference: 21. Topical Conference on High Temperature Plasma Diagnostics (HTPD 2016), Madison, WI (United States), 5-9 Jun 2016; Journal ID: ISSN 0034-6748
American Institute of Physics (AIP)
Research Org:
Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
70 PLASMA PHYSICS AND FUSION TECHNOLOGY Neutrons; Protons; secondary-electrons (SE)