Prompt and Delayed Neutron Emissions and Fission Product Yield Calculations with Hauser-Feshbach Statistical Decay Theory and Summation Calculation Method

¹ Laboratory for Advanced Nuclear Energy, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguroku, Tokyo, 152-8550, Japan
² Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
³ NAPC-Nuclear Data Section, International Atomic Energy Agency, Vienna A-1400, Austria

^* e-mail: s.okumura@iaea.org
^** e-mail: kawano@lanl.gov
^*** e-mail: chiba.satoshi@nr.titech.ac.jp

Published online: 5 June 2019

Abstract

We demonstrate the neutron emission and fission product yield calculations using the Hauser–Feshbach Fission Fragment Decay (HF³D) model and β decay. The HF³D model calculates the statistical decay of more than 500 primary fission fragment pairs formed by the neutron induced fission of ²³⁵U. In order to calculate the prompt neutron and photon emissions, the primary fission fragment distributions, i.e. mass, charge, excitation energy, spin and parity are deterministically generated and numerically integrated for all fission fragments. The calculated prompt neutron multiplicities, independent fission product yield are fully consistent each other. We combine the β-decay and the summation calculations with the HF³D model calculation to obtain the cumulative fission product yield, decay heat and delayed neutron yield. The calculated fission observables are compared with available experimental data.