Fission Chain Restart Theory

Kim, K. S.; Nakae, L. F.; Prasad, M. K.; Snyderman, N. J.; Verbeke, J. M.

doi:10.1080/00295639.2017.1340691

Title: Fission Chain Restart Theory

Abstract

We present that fast nanosecond timescale neutron and gamma-ray counting can be performed with a (liquid) scintillator array. Fission chains in metal evolve over a timescale of tens of nanoseconds. If the metal is surrounded by moderator, neutrons leaking from the metal can thermalize and diffuse in the moderator. With finite probability, the diffusing neutrons can return to the metal and restart the fast fission chain. The timescale for this restart process is microseconds. A theory describing time evolving fission chains for metal surrounded by moderator, including this restart process, is presented. Finally, this theory is sufficiently simple for it to be implemented for real-time analysis.

Authors:

^[1]; Nakae, L. F. ^[1]; Prasad, M. K. ^[1]; Snyderman, N. J. ^[1]; Verbeke, J. M. ^[1]

Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Publication Date:: Mon Jul 31 00:00:00 EDT 2017

Research Org.:: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 1438761

Report Number(s):: LLNL-JRNL-704257
Journal ID: ISSN 0029-5639; TRN: US1900515

Grant/Contract Number:: AC52-07NA27344

Resource Type:: Accepted Manuscript

Journal Name:: Nuclear Science and Engineering

Additional Journal Information:: Journal Volume: 188; Journal Issue: 1; Journal ID: ISSN 0029-5639

Publisher:: American Nuclear Society - Taylor & Francis

Country of Publication:: United States

Language:: English

Subject:: 98 NUCLEAR DISARMAMENT, SAFEGUARDS AND PHYSICAL PROTECTION; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 97 MATHEMATICS AND COMPUTING; Mathematical modeling; fast neutron counting; gamma-ray counting

Citation Formats


                    Kim, K. S., Nakae, L. F., Prasad, M. K., Snyderman, N. J., and Verbeke, J. M. Fission Chain Restart Theory.  United States: N. p., 2017. 
Web.  doi:10.1080/00295639.2017.1340691.

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                    Kim, K. S., Nakae, L. F., Prasad, M. K., Snyderman, N. J., & Verbeke, J. M. Fission Chain Restart Theory.  United States.  https://doi.org/10.1080/00295639.2017.1340691

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                    Kim, K. S., Nakae, L. F., Prasad, M. K., Snyderman, N. J., and Verbeke, J. M. Mon .  
"Fission Chain Restart Theory".  United States.  https://doi.org/10.1080/00295639.2017.1340691.  https://www.osti.gov/servlets/purl/1438761.

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@article{osti_1438761,

  title        = {Fission Chain Restart Theory},

  author       = {Kim, K. S. and Nakae, L. F. and Prasad, M. K. and Snyderman, N. J. and Verbeke, J. M.},

  abstractNote = {We present that fast nanosecond timescale neutron and gamma-ray counting can be performed with a (liquid) scintillator array. Fission chains in metal evolve over a timescale of tens of nanoseconds. If the metal is surrounded by moderator, neutrons leaking from the metal can thermalize and diffuse in the moderator. With finite probability, the diffusing neutrons can return to the metal and restart the fast fission chain. The timescale for this restart process is microseconds. A theory describing time evolving fission chains for metal surrounded by moderator, including this restart process, is presented. Finally, this theory is sufficiently simple for it to be implemented for real-time analysis.},

  doi          = {10.1080/00295639.2017.1340691},

  journal      = {Nuclear Science and Engineering},

  number       = 1,

  volume       = 188,

  place        = {United States},

  year         = {Mon Jul 31 00:00:00 EDT 2017},

  month        = {Mon Jul 31 00:00:00 EDT 2017}

}

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Journal Article:

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Works referenced in this record:

Probability distribution of neutrons and precursors in a multiplying assembly
journal, February 1963

Bell, George I.
Annals of Physics, Vol. 21, Issue 2
DOI: 10.1016/0003-4916(63)90108-8

On the Stochastic Theory of Neutron Transport
journal, March 1965

Bell, George I.
Nuclear Science and Engineering, Vol. 21, Issue 3
DOI: 10.13182/NSE65-1

Time Interval Distributions and the Rossi Correlation Function
journal, May 2013

Prasad, M.; Snyderman, N.; Verbeke, J.
Nuclear Science and Engineering, Vol. 174, Issue 1
DOI: 10.13182/NSE11-87

The Effect of Multiplication on the Quantitative Determination of Spontaneously Fissioning Isotopes by Neutron Correlation Analysis
journal, May 1985

Böhnel, K.
Nuclear Science and Engineering, Vol. 90, Issue 1
DOI: 10.13182/NSE85-2

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Title: Fission Chain Restart Theory

Abstract

Citation Formats

Probability distribution of neutrons and precursors in a multiplying assembly journal, February 1963

On the Stochastic Theory of Neutron Transport journal, March 1965

Time Interval Distributions and the Rossi Correlation Function journal, May 2013

The Effect of Multiplication on the Quantitative Determination of Spontaneously Fissioning Isotopes by Neutron Correlation Analysis journal, May 1985

Probability distribution of neutrons and precursors in a multiplying assembly
journal, February 1963

On the Stochastic Theory of Neutron Transport
journal, March 1965

Time Interval Distributions and the Rossi Correlation Function
journal, May 2013

The Effect of Multiplication on the Quantitative Determination of Spontaneously Fissioning Isotopes by Neutron Correlation Analysis
journal, May 1985