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Title: Velocity correction for neutron activation diagnostics at the NIF

Abstract

The velocity distribution of the hotspot in an inertial confinement fusion implosion changes the energy spectra of fusion neutrons emitted from the experiment as a function of viewing angle. These velocity-induced spectral changes affect the response of neutron activation diagnostics (NADs) positioned around the experiment and must be accounted for to correctly extract information about areal density (ρR) asymmetry from the data. Three mechanisms through which average hotspot velocity affects NAD activation are addressed: change in activation cross section due to the Doppler shift of the mean neutron energy, kinematic focusing of neutron fluence, and change in the scattering cross section due to the Doppler shift. Using the hotspot velocity inferred from neutron time-of-flight measurements of D-T and D-D fusion neutrons, the hotspot velocity is shown to account for the observed NAD activation asymmetry in a calibration shot with negligible fuel ρR. Finally, a robust method to evaluate uncertainties in spherical-harmonic fits to the NAD data due to the velocity correction and detector uncertainty is discussed.

Authors:
ORCiD logo [1];  [1];  [1];  [1];  [1]; ORCiD logo [1]; ORCiD logo [1]
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  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1479059
Alternate Identifier(s):
OSTI ID: 1476964
Report Number(s):
LLNL-JRNL-750006
Journal ID: ISSN 0034-6748; 935047
Grant/Contract Number:  
AC52-07NA27344
Resource Type:
Accepted Manuscript
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 89; Journal Issue: 10; Journal ID: ISSN 0034-6748
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION; Lasers

Citation Formats

Rinderknecht, Hans G., Bionta, R., Grim, G., Hatarik, R., Khater, H., Schlossberg, D., and Yeamans, C. Velocity correction for neutron activation diagnostics at the NIF. United States: N. p., 2018. Web. doi:10.1063/1.5038734.
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Rinderknecht, Hans G., Bionta, R., Grim, G., Hatarik, R., Khater, H., Schlossberg, D., & Yeamans, C. Velocity correction for neutron activation diagnostics at the NIF. United States. doi:https://doi.org/10.1063/1.5038734
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Rinderknecht, Hans G., Bionta, R., Grim, G., Hatarik, R., Khater, H., Schlossberg, D., and Yeamans, C. Mon . "Velocity correction for neutron activation diagnostics at the NIF". United States. doi:https://doi.org/10.1063/1.5038734. https://www.osti.gov/servlets/purl/1479059.
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@article{osti_1479059,
title = {Velocity correction for neutron activation diagnostics at the NIF},
author = {Rinderknecht, Hans G. and Bionta, R. and Grim, G. and Hatarik, R. and Khater, H. and Schlossberg, D. and Yeamans, C.},
abstractNote = {The velocity distribution of the hotspot in an inertial confinement fusion implosion changes the energy spectra of fusion neutrons emitted from the experiment as a function of viewing angle. These velocity-induced spectral changes affect the response of neutron activation diagnostics (NADs) positioned around the experiment and must be accounted for to correctly extract information about areal density (ρR) asymmetry from the data. Three mechanisms through which average hotspot velocity affects NAD activation are addressed: change in activation cross section due to the Doppler shift of the mean neutron energy, kinematic focusing of neutron fluence, and change in the scattering cross section due to the Doppler shift. Using the hotspot velocity inferred from neutron time-of-flight measurements of D-T and D-D fusion neutrons, the hotspot velocity is shown to account for the observed NAD activation asymmetry in a calibration shot with negligible fuel ρR. Finally, a robust method to evaluate uncertainties in spherical-harmonic fits to the NAD data due to the velocity correction and detector uncertainty is discussed.},
doi = {10.1063/1.5038734},
journal = {Review of Scientific Instruments},
number = 10,
volume = 89,
place = {United States},
year = {2018},
month = {10}
}
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DOI:  https://doi.org/10.1063/1.5038734
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Works referenced in this record:

Relativistic calculation of fusion product spectra for thermonuclear plasmas
journal, November 1998

The Spatially Distributed Neutron Activation Diagnostic FNADs at the National Ignition Facility
journal, May 2017

The National Ignition Facility neutron time-of-flight system and its initial performance (invited)
journal, October 2010

  • Glebov, V. Yu.; Sangster, T. C.; Stoeckl, C.
  • Review of Scientific Instruments, Vol. 81, Issue 10
  • DOI: 10.1063/1.3492351

Using multiple neutron time of flight detectors to determine the hot spot velocity
journal, October 2018

  • Hatarik, R.; Nora, R. C.; Spears, B. K.
  • Review of Scientific Instruments, Vol. 89, Issue 10
  • DOI: 10.1063/1.5039372

Dynamic high energy density plasma environments at the National Ignition Facility for nuclear science research
journal, February 2018

  • Cerjan, Ch J.; Bernstein, L.; Hopkins, L. Berzak
  • Journal of Physics G: Nuclear and Particle Physics, Vol. 45, Issue 3
  • DOI: 10.1088/1361-6471/aa8693

Testing a new NIF neutron time-of-flight detector with a bibenzyl scintillator on OMEGA
journal, October 2012

  • Glebov, V. Yu.; Forrest, C.; Knauer, J. P.
  • Review of Scientific Instruments, Vol. 83, Issue 10
  • DOI: 10.1063/1.4731001

Interpreting inertial fusion neutron spectra
journal, February 2016

Capsule modeling of high foot implosion experiments on the National Ignition Facility
journal, March 2017

  • Clark, D. S.; Kritcher, A. L.; Milovich, J. L.
  • Plasma Physics and Controlled Fusion, Vol. 59, Issue 5
  • DOI: 10.1088/1361-6587/aa6216

Mode 1 drive asymmetry in inertial confinement fusion implosions on the National Ignition Facility
journal, April 2014

  • Spears, Brian K.; Edwards, M. J.; Hatchett, S.
  • Physics of Plasmas, Vol. 21, Issue 4
  • DOI: 10.1063/1.4870390

ENDF/B-VII.0: Next Generation Evaluated Nuclear Data Library for Nuclear Science and Technology
journal, December 2006

Analysis of the neutron time-of-flight spectra from inertial confinement fusion experiments
journal, November 2015

  • Hatarik, R.; Sayre, D. B.; Caggiano, J. A.
  • Journal of Applied Physics, Vol. 118, Issue 18
  • DOI: 10.1063/1.4935455
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    Works referencing / citing this record:

    Synthetic nuclear diagnostics for inferring plasma properties of inertial confinement fusion implosions
    journal, December 2018

    • Crilly, A. J.; Appelbe, B. D.; McGlinchey, K.
    • Physics of Plasmas, Vol. 25, Issue 12
    • DOI: 10.1063/1.5027462

    Progress of indirect drive inertial confinement fusion in the United States
    journal, July 2019

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