Isomeric cross sections of fast-neutron induced reactions on $^{197}$Au

TL;DR

This paper analyzes recent data on isomeric cross sections of neutron-induced reactions on gold-197 to infer the nucleus's effective moment of inertia, confirming a rigid-body value for gold-196 and suggesting a half rigid-body for iridium-194.

Contribution

It provides a local consistent model analysis of reaction data to determine the effective moment of inertia of nuclei involved in neutron reactions.

Findings

Confirmed rigid-body moment of inertia for $^{196}$Au

Suggested half rigid-body moment for $^{194}$Ir

Highlighted importance of measurements up to 40 MeV

Abstract

Recent accurate data obtained for the isomeric cross section of the $^{197}$Au$(n,2n)$ reaction provide a valuable opportunity to consider the question of the effective moment of inertia of the nucleus within a local consistent model analysis of all available reaction data for the $^{197}$Au target nucleus. Thus, a definite proof of a moment of inertia equal to that of the rigid--body has been obtained for $^{196}$Au nucleus while an inference of the half rigid--body value is suggested for the $^{194}$Ir nucleus. The usefulness of further measurements at incident energies up to $\ge$40 MeV has also been proved.