DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Interpreting inertial fusion neutron spectra

Abstract

A burning laser fusion plasma produces a neutron spectrum first described by Brysk (1973 Plasma Phys. Control. Fusion 15 611). This and more recent work deals with the spectrum produced by a single fluid element. The distribution of temperatures and velocities in multiple fluid elements combine in any real spectrum; here we derive formulas for how the neutron spectrum averages these contributions. The single element momentum spectrum is accurately Gaussian, but the multi-element spectrum exhibits higher moments. In particular, the skew and kurtosis are likely to be large enough to measure. Even the single fluid element spectrum may exhibit measurable directional anisotropy, so that instruments with different lines of sight should see different yields, mean velocities, mean temperatures, and higher moments. Finally, we briefly discuss how scattering in the imploded core modifies the neutron spectrum by changing the relative weighting of fuel regions with different temperatures and velocities.

Authors:
 [1]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Research Org.:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1240980
Report Number(s):
LLNL-JRNL-676641
Journal ID: ISSN 0029-5515
Grant/Contract Number:  
AC52-07NA27344
Resource Type:
Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 56; Journal Issue: 3; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 70 PLASMA PHYSICS AND FUSION

Citation Formats

Munro, David H. Interpreting inertial fusion neutron spectra. United States: N. p., 2016. Web. doi:10.1088/0029-5515/56/3/036001.
Munro, David H. Interpreting inertial fusion neutron spectra. United States. https://doi.org/10.1088/0029-5515/56/3/036001
Munro, David H. Fri . "Interpreting inertial fusion neutron spectra". United States. https://doi.org/10.1088/0029-5515/56/3/036001. https://www.osti.gov/servlets/purl/1240980.
@article{osti_1240980,
title = {Interpreting inertial fusion neutron spectra},
author = {Munro, David H.},
abstractNote = {A burning laser fusion plasma produces a neutron spectrum first described by Brysk (1973 Plasma Phys. Control. Fusion 15 611). This and more recent work deals with the spectrum produced by a single fluid element. The distribution of temperatures and velocities in multiple fluid elements combine in any real spectrum; here we derive formulas for how the neutron spectrum averages these contributions. The single element momentum spectrum is accurately Gaussian, but the multi-element spectrum exhibits higher moments. In particular, the skew and kurtosis are likely to be large enough to measure. Even the single fluid element spectrum may exhibit measurable directional anisotropy, so that instruments with different lines of sight should see different yields, mean velocities, mean temperatures, and higher moments. Finally, we briefly discuss how scattering in the imploded core modifies the neutron spectrum by changing the relative weighting of fuel regions with different temperatures and velocities.},
doi = {10.1088/0029-5515/56/3/036001},
journal = {Nuclear Fusion},
number = 3,
volume = 56,
place = {United States},
year = {Fri Feb 05 00:00:00 EST 2016},
month = {Fri Feb 05 00:00:00 EST 2016}
}

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

Citation Metrics:
Cited by: 59 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

The 27.3 meter neutron time-of-flight system for the National Ignition Facility
conference, September 2013

  • Grim, G. P.; Morgan, G. L.; Aragonez, R.
  • SPIE Optical Engineering + Applications, SPIE Proceedings
  • DOI: 10.1117/12.2030170

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

Relativistically correct DD and DT neutron spectra
journal, June 2014


A New Neutron Time-of-Flight Detector to Measure the MeV Neutron Spectrum at the National Ignition Facility
journal, January 2014

  • Hatarik, Robert; Caggiano, Joseph A.; Glebov, Vladimir
  • Plasma and Fusion Research, Vol. 9, Issue 0
  • DOI: 10.1585/pfr.9.4404104

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


Three-dimensional simulations of National Ignition Facility implosions: Insight into experimental observablesa)
journal, May 2015

  • Spears, Brian K.; Munro, David H.; Sepke, Scott
  • Physics of Plasmas, Vol. 22, Issue 5
  • DOI: 10.1063/1.4920957

The production spectrum in fusion plasmas
journal, February 2011


The effect of turbulent kinetic energy on inferred ion temperature from neutron spectra
journal, July 2014


Improved formulas for fusion cross-sections and thermal reactivities
journal, April 1992


Species separation and modification of neutron diagnostics in inertial-confinement fusion
journal, September 2014


Fusion cross sections and thermonuclear reaction rates
journal, September 1979

  • Peres, Asher
  • Journal of Applied Physics, Vol. 50, Issue 9
  • DOI: 10.1063/1.326748

Measurements of collective fuel velocities in deuterium-tritium exploding pusher and cryogenically layered deuterium-tritium implosions on the NIF
journal, April 2013

  • Gatu Johnson, M.; Casey, D. T.; Frenje, J. A.
  • Physics of Plasmas, Vol. 20, Issue 4
  • DOI: 10.1063/1.4802810

Diagnosing implosion performance at the National Ignition Facility (NIF) by means of neutron spectrometry
journal, March 2013


Revised Knudsen-layer reduction of fusion reactivity
journal, December 2013

  • Albright, B. J.; Molvig, Kim; Huang, C. -K.
  • Physics of Plasmas, Vol. 20, Issue 12
  • DOI: 10.1063/1.4833639

One-dimensional particle simulations of Knudsen-layer effects on D-T fusion
journal, December 2014

  • Cohen, Bruce I.; Dimits, Andris M.; Zimmerman, George B.
  • Physics of Plasmas, Vol. 21, Issue 12
  • DOI: 10.1063/1.4903323

Engineering architecture of the neutron Time-of-Flight (nToF) diagnostic suite at the National Ignition Facility
conference, September 2014

  • Clancy, T. J.; Caggiano, J.; McNaney, J.
  • SPIE Optical Engineering + Applications, SPIE Proceedings
  • DOI: 10.1117/12.2062329

Fusion neutron energies and spectra
journal, July 1973


Improved formulas for fusion cross-sections and thermal reactivities
journal, December 1993


Relativistic Mechanics
book, June 2019


Relativistic Mechanics
journal, December 1971

  • Sard, R. D.; Perlmutter, Arnold
  • American Journal of Physics, Vol. 39, Issue 12
  • DOI: 10.1119/1.1976721

Relativistic Mechanics
book, January 1972


Species separation and modification of neutron diagnostics in inertial-confinement fusion
text, January 2014


Works referencing / citing this record:

Parameter inference with deep jointly informed neural networks
journal, July 2019

  • Humbird, Kelli D.; Peterson, J. Luc; McClarren, Ryan G.
  • Statistical Analysis and Data Mining: The ASA Data Science Journal, Vol. 12, Issue 6
  • DOI: 10.1002/sam.11435

Impact of temperature-velocity distribution on fusion neutron peak shape
journal, May 2017

  • Munro, D. H.; Field, J. E.; Hatarik, R.
  • Physics of Plasmas, Vol. 24, Issue 5
  • DOI: 10.1063/1.4976857

Effects of residual kinetic energy on yield degradation and ion temperature asymmetries in inertial confinement fusion implosions
journal, May 2018

  • Woo, K. M.; Betti, R.; Shvarts, D.
  • Physics of Plasmas, Vol. 25, Issue 5
  • DOI: 10.1063/1.5026706

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

Calibration of a neutron time-of-flight detector with a rapid instrument response function for measurements of bulk fluid motion on OMEGA
journal, October 2018

  • Mannion, O. M.; Glebov, V. Yu.; Forrest, C. J.
  • Review of Scientific Instruments, Vol. 89, Issue 10
  • DOI: 10.1063/1.5037324

Velocity correction for neutron activation diagnostics at the NIF
journal, October 2018

  • Rinderknecht, Hans G.; Bionta, R.; Grim, G.
  • Review of Scientific Instruments, Vol. 89, Issue 10
  • DOI: 10.1063/1.5038734

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

Ab initio response functions for Cherenkov-based neutron detectors
journal, October 2018

  • Schlossberg, D. J.; Moore, A. S.; Beeman, B. V.
  • Review of Scientific Instruments, Vol. 89, Issue 10
  • DOI: 10.1063/1.5039399

Neutron backscatter edge: A measure of the hydrodynamic properties of the dense DT fuel at stagnation in ICF experiments
journal, January 2020

  • Crilly, A. J.; Appelbe, B. D.; Mannion, O. M.
  • Physics of Plasmas, Vol. 27, Issue 1
  • DOI: 10.1063/1.5128830

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

Spectral composition of thermonuclear particle and recoil nuclear emissions from laser fusion targets intended for modern ignition experiments
journal, June 2018

  • Gus’kov, S. Yu; Il’in, D. V.; Perlado, J. M.
  • Plasma Physics and Controlled Fusion, Vol. 60, Issue 8
  • DOI: 10.1088/1361-6587/aac739

Compression and burning of a direct-driven thermonuclear target under the conditions of inhomogeneous heating by a multi-beam megajoule laser
journal, January 2019

  • Bel’kov, S. A.; Bondarenko, S. V.; Demchenko, N. N.
  • Plasma Physics and Controlled Fusion, Vol. 61, Issue 2
  • DOI: 10.1088/1361-6587/aaf062

Nuclear diagnostics for Inertial Confinement Fusion (ICF) plasmas
journal, January 2020