Measurement of the Isomeric Yield Ratio for Zirconium-88 Thermal Neutron Absorption

TL;DR

This study measures the isomeric yield ratio of zirconium-89 produced from zirconium-88 neutron absorption, revealing a high metastable state production rate relevant for nuclear physics and reactor applications.

Contribution

The paper provides the first precise measurement of the isomeric yield ratio for zirconium-89 from zirconium-88 neutron absorption.

Findings

Isomeric yield ratio of 74.9% for zirconium-89.

Implications for neutron absorption measurements and nuclear data.

Enhanced understanding of metastable state production in zirconium-88.

Abstract

In light of the recently observed 800,000 barn thermal neutron absorption cross section of zirconium-88, this work investigates the fraction (isomeric yield ratio) of metastable versus ground state production of zirconium-89 and implications for ongoing measurements around zirconium-88 neutron absorption. The metastable state of zirconium-89 resides at 588 keV above the ground state with a half life of 4.2 minutes. A 5 $\mu$Ci zirconium-88 sample was irradiated for 10 minutes in the core of a TRIGA Mark II nuclear research reactor and measured with a high purity germanium detector 3 minutes after irradiation. The isomeric yield ratio was measured to be 74.9$\pm$0.6\%.