Evaluation of Polyethylene and Blank Pulsed Sphere Experiments Using Deuteron Transport Feature in COG

Journal Article · 01 December 2021 · Transactions of the American Nuclear Society

DOI: https://doi.org/10.13182/T125-36616 · OSTI ID:1957960

Kim, Soon S. ^[1]; Heinrichs, David P. ^[1]; Lent, Edward M. ^[1]

---

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

From the late 1960s to about 1985, LLNL undertook a series of ‘pulsed sphere’ experiments for 31 materials involving 148 different experiments using 75 different spheres. The purpose was to measure the neutron leakage spectra for different materials from 14-MeV neutrons generated by ³H(d,n)⁴He reactions induced by an incident D+ beam from the Insulated Core Transfer (ICT) accelerator at LLNL. This deuteron beam was focused to impinge upon tritium loaded onto a titanium substrate within a low mass target assembly placed within the center of a spherical shell constructed from the material of interest. COG is a three-dimensional, continuous energy, Monte Carlo code, developed by Lawrence Livermore National Laboratory (LLNL). Recent additions to COG include alpha and deuteron particle transport in order to directly calculate (α,n) and ³H(d,n)⁴He reactions, and resulting neutron emission spectra. Results of the direct deuteron transport calculation for the 0.8 MFP (mean free path) polyethylene sphere with PILOT B detector was previously published. The purpose of this paper is to present expanded COG results showing the neutron peak from deuterium buildup (²H(d,n)³He) due to tritium decay in the target. Cross section data libraries used are ENDF/B-VIII.0 for neutrons and ENDF/B-VII.1 for deuterons, respectively.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
• Grant/Contract Number: AC52-07NA27344
• OSTI ID: 1957960
• Report Number(s): LLNL-ABS-820246; TRN: US2312669
• Journal Information: Transactions of the American Nuclear Society, Vol. 125, Issue 1; Conference: 2021 ANS Winter Meeting and Technology Expo, Washington, DC (United States, 30 Nov - 3 Dec 2021; Related Information: https://www.ans.org/meetings/wm2021/session/view-859/; ISSN 0003-018X
• Publisher: American Nuclear SocietyCopyright Statement
• Country of Publication: United States
• Language: English