239Pu(n, 2n) and 241Pu(n, 2n) surrogate cross section measurements using NeutronSTARS

Technical Report · Fri Dec 08 00:00:00 EST 2017

DOI:https://doi.org/10.2172/1416503· OSTI ID:1416503

Burke, J. T. ^[1]; Alan, B. S. ^[1]; Akindele, O. A. ^[2]; Casperson, R. J. ^[1]; Hughes, R. O. ^[1]; Koglin, J. D. ^[1]; Tamashiro, A. ^[3]; Kolos, K. ^[1]; Norman, E. B. ^[2]; Saastamoinen, A. ^[4]; Padilla, A. ^[5]; Fisher, S. ^[1]

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1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2. Univ. of California, Berkeley, CA (United States)
3. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Oregon State Univ., Corvallis, OR (United States)
4. Univ. of California, Los Angeles, CA (United States)
5. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Univ. of California, Los Angeles, CA (United States)

The goal of this project was to develop a new approach to measuring (n,2n) reactions for isotopes of interest. We set out to measure the ²³⁹Pu(n,2n) and ²⁴¹Pu(n,2n) cross sections by directly detecting the 2n neutrons that are emitted. With the goal of improving the ²³⁹Pu(n,2n) cross section and to measure the ²⁴¹Pu(n,2n) cross section for the first time. To that end, we have constructed a new neutron-charged-particle detector array called NeutronSTARS. It has been described extensively in Casperson et al. [1] and in Akindele et al. [2]. We have used this new neutron-charged-particle array to measure the ²⁴¹Pu and ²³⁹Pu fission neutron multiplicity as a function of equivalent incident-neutron energy from 100 keV to 20 MeV. We have made a preliminary determination of the ²³⁹Pu(n,2n) and ²⁴¹Pu(n,2n) cross sections from the surrogate ²⁴⁰Pu(α,α’2n) and ²⁴²Pu(α,α’2n) reactions respectively. The experimental approach, detector array, data analysis, and results to date are summarized in the following sections.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC52-07NA27344
• OSTI ID: 1416503
• Report Number(s): LLNL-TR-743617; TRN: US1801173
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
FISSION NEUTRONS
PLUTONIUM 241
PLUTONIUM 239
CROSS SECTIONS