Evaluation of Neutron Production Cross Sections of Tungsten Isotopes for Fusion Applications

Abstract

The evaluation of neutron production cross section is presented for tungsten which is increasingly considered as a prime candidate of plasma facing materials in fusion reactors. The energy and/or angular dependent neutron spectra from existing libraries such as ENDF/B-VII, JEFF-3.1 and JENDL-3.3 failed to reproduce the measured data available for tungsten isotopes. Moreover, the integral tests of neutron production from these libraries showed remarkable discrepancies with leakage neutron measurements of OKTAVIAN. In response to these situations, we calculated the neutron production data for four tungsten isotopes such as 182,183,184,186W. The calculation was performed by using the nuclear model code EMPIRE-2.19 with a consistent set of input parameters for all tungsten isotopes. We could obtain the neutron spectra in good agreements with the measurements by employing the quantum mechanical Multi-Step Direct (MSD) and Multi-Step Compound (MSC) theory for preequilibrium neutron emission. The results have been complied into ENDF-6 format, and the neutron production data have been validated through some fusion neutronics shielding experiments in the SINBAD.