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Title: Optimizing neutron imaging line of sight locations for maximizing sampling of the cold fuel density in inertial confinement fusion implosions at the National Ignition Facility

Abstract

We report that neutron imaging provides a ready measurement of the shape of the “hot spot” core of an inertial confinement fusion implosion. The 14-MeV neutrons emitted by deuterium-tritium reactions are imaged at the National Ignition Facility using a pinhole array onto a scintillator, and the images are recorded on a camera. By changing the gate time of the camera, lower energy neutrons, downscattered by the cold fuel surrounding the hot spot, are recorded. The cold fuel density can be reconstructed using the two images. The kinematics of the scattering coupled with the scattering cross sections restrict the angular extent of the cold fuel sampled, with the backside of the implosion not being sampled at all. This work demonstrates the limited region of the cold fuel measured by the current line of sight (40%). Finally, at completion of the three planned lines of sight, 79% of the cold fuel will be sampled.

Authors:
 [1];  [1];  [1]; ORCiD logo [1];  [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1482000
Alternate Identifier(s):
OSTI ID: 1478679
Report Number(s):
LA-UR-18-23951
Journal ID: ISSN 0034-6748
Grant/Contract Number:  
AC52-06NA25396
Resource Type:
Accepted Manuscript
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 89; Journal Issue: 10; Conference: High Temperature Plasma Diagnostics ; 2018-04-16 - 2018-04-19 ; San Diego, California, United States; Journal ID: ISSN 0034-6748
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Batha, S. H., Volegov, P. L., Fatherley, V. E., Geppert-Kleinrath, V., and Wilde, C. H. Optimizing neutron imaging line of sight locations for maximizing sampling of the cold fuel density in inertial confinement fusion implosions at the National Ignition Facility. United States: N. p., 2018. Web. doi:10.1063/1.5038815.
Batha, S. H., Volegov, P. L., Fatherley, V. E., Geppert-Kleinrath, V., & Wilde, C. H. Optimizing neutron imaging line of sight locations for maximizing sampling of the cold fuel density in inertial confinement fusion implosions at the National Ignition Facility. United States. doi:10.1063/1.5038815.
Batha, S. H., Volegov, P. L., Fatherley, V. E., Geppert-Kleinrath, V., and Wilde, C. H. Wed . "Optimizing neutron imaging line of sight locations for maximizing sampling of the cold fuel density in inertial confinement fusion implosions at the National Ignition Facility". United States. doi:10.1063/1.5038815. https://www.osti.gov/servlets/purl/1482000.
@article{osti_1482000,
title = {Optimizing neutron imaging line of sight locations for maximizing sampling of the cold fuel density in inertial confinement fusion implosions at the National Ignition Facility},
author = {Batha, S. H. and Volegov, P. L. and Fatherley, V. E. and Geppert-Kleinrath, V. and Wilde, C. H.},
abstractNote = {We report that neutron imaging provides a ready measurement of the shape of the “hot spot” core of an inertial confinement fusion implosion. The 14-MeV neutrons emitted by deuterium-tritium reactions are imaged at the National Ignition Facility using a pinhole array onto a scintillator, and the images are recorded on a camera. By changing the gate time of the camera, lower energy neutrons, downscattered by the cold fuel surrounding the hot spot, are recorded. The cold fuel density can be reconstructed using the two images. The kinematics of the scattering coupled with the scattering cross sections restrict the angular extent of the cold fuel sampled, with the backside of the implosion not being sampled at all. This work demonstrates the limited region of the cold fuel measured by the current line of sight (40%). Finally, at completion of the three planned lines of sight, 79% of the cold fuel will be sampled.},
doi = {10.1063/1.5038815},
journal = {Review of Scientific Instruments},
number = 10,
volume = 89,
place = {United States},
year = {2018},
month = {10}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Figures / Tables:

FIG. 1 FIG. 1: The ratio of neutron energy after and before collisions with hydrogen (solid black line), deuterium (long/short dashed red line), and tritium (dashed green line) as a function of scattering angle in the laboratory frame.

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Works referenced in this record:

Nuclear imaging of the fuel assembly in ignition experiments
journal, May 2013

  • Grim, G. P.; Guler, N.; Merrill, F. E.
  • Physics of Plasmas, Vol. 20, Issue 5
  • DOI: 10.1063/1.4807291

The neutron imaging diagnostic at NIF (invited)
journal, October 2012

  • Merrill, F. E.; Bower, D.; Buckles, R.
  • Review of Scientific Instruments, Vol. 83, Issue 10
  • DOI: 10.1063/1.4739242

Analysis of NIF experiments with the minimal energy implosion model
journal, August 2015

  • Cheng, B.; Kwan, T. J. T.; Wang, Y. M.
  • Physics of Plasmas, Vol. 22, Issue 8
  • DOI: 10.1063/1.4928093

Three-dimensional reconstruction of neutron, gamma-ray, and x-ray sources using spherical harmonic decomposition
journal, November 2017

  • Volegov, P. L.; Danly, C. R.; Fittinghoff, D.
  • Journal of Applied Physics, Vol. 122, Issue 17
  • DOI: 10.1063/1.4986652

Consequences of Neutron-Proton Mass Difference in the Kinematics of Neutron-Proton Scattering
journal, February 1964

  • Ghatak, Ajoy K.
  • American Journal of Physics, Vol. 32, Issue 2
  • DOI: 10.1119/1.1970145

The National Ignition Facility Diagnostic Set at the Completion of the National Ignition Campaign, September 2012
journal, February 2016

  • Kilkenny, J. D.; Bell, P. M.; Bradley, D. K.
  • Fusion Science and Technology, Vol. 69, Issue 1
  • DOI: 10.13182/FST15-173

Aperture design for the third neutron and first gamma-ray imaging systems for the National Ignition Facility
journal, October 2018

  • Fatherley, V. E.; Fittinghoff, D. N.; Hibbard, R. L.
  • Review of Scientific Instruments, Vol. 89, Issue 10
  • DOI: 10.1063/1.5039328

The experimental plan for cryogenic layered target implosions on the National Ignition Facility—The inertial confinement approach to fusion
journal, May 2011

  • Edwards, M. J.; Lindl, J. D.; Spears, B. K.
  • Physics of Plasmas, Vol. 18, Issue 5
  • DOI: 10.1063/1.3592173

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