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Title: Neutron angular distribution in plutonium-240 spontaneous fission

Journal Article · · Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment
 [1];  [1];  [1];  [2];  [1]
  1. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences
  2. European Commission at the Joint Research Centre, Ispra (Italy)
+ Show Author Affiliations

Nuclear safeguards applications require accurate fission models that exhibit prompt neutron anisotropy. We observed an anisotropic neutron angular distribution, in the laboratory reference frame, because prompt fission neutrons carry momentum from fully accelerated fission fragments. Furthermore, a liquid organic scintillation detector array was used with pulse shape discrimination techniques to produce neutron-neutron cross-correlation time distributions and angular distributions from spontaneous fission in a 252Cf, a 0.84 g 240Pueff metal, and a 1.63 g 240Pueff metal sample. The effect of cross-talk, estimated with MCNPX-PoliMi simulations, is removed from neutron-neutron coincidences as a function of the angle between detector pairs. Fewer coincidences were observed at detector angles near 90°, relative to higher and lower detector angles. As light output threshold increases, the observed anisotropy increases due to spectral effects arising from fission fragment momentum transfer to emitted neutrons. Stronger anisotropy was observed in Cf-252 spontaneous fission prompt neutrons than in Pu-240 neutrons.

Research Organization:
Univ. of Michigan, Ann Arbor, MI (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation
Grant/Contract Number:
NA0002534; NE0000393; LA14-FY14-027-PD2J
OSTI ID:
1487063
Alternate ID(s):
OSTI ID: 1341190; OSTI ID: 1365835
Journal Information:
Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 830, Issue C; ISSN 0168-9002
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 11 works
Citation information provided by
Web of Science

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Cited By (3)

High resolution measurement of tagged two-neutron energy and angle correlations in Cf 252 (sf) journal July 2019
Correlated prompt fission data in transport simulations journal January 2018
Correlated Prompt Fission Data in Transport Simulations text January 2017

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46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL PROTECTION
Fission neutron anisotropy
Plutonium
Nuclear safeguards
MCNPX-PoliMi