Reaction Rate Distributions and Related Data in the Fusion Neutron Source Phase II Experiments: Comparison of Measured and Calculated Data

Neutronics parameters including the source neutron spectrum, activation rates, and the tritium breeding in the Li₂O test zone of the Fusion Neutron Source Phase II experiment performed at the Japan Atomic Energy Research Institute are calculated using the Monte Carlo code MORSE with ENDF/B-V transport and reaction cross sections. Favorable comparisons between the measured and calculated results are achieved for the ²⁷Al(n,α), ⁵⁸Ni(n,p), ⁹³Nb(n,2n), and ¹⁹⁷Au(n,2n) reactions. Calculated ⁵⁸Ni(n,2n) and ¹⁹⁷Au(n,γ) reactions do not agree with measured values within 10 to 40%. For the nickel reaction, the differences may be due to poor data in the ORACT files, while discrepancies for the gold data may be due to unknown quantities of hydrogen-rich epoxy used to coat the Li₂CO₃ blocks used in the test assembly walls. The calculated tritium breeding in the Li₂O agrees with experimental values within ±10% for ⁶Li and ±15 to 20% for ⁷Li.