Excitation Function of the nat-Ta(p,x)178m2-Hf Reaction

TL;DR

This study measures the production cross-sections of the isomeric state 178m2-Hf from proton irradiation of natural tantalum across a wide energy range, providing new experimental data and model comparisons.

Contribution

First experimental determination of 178m2-Hf excitation function from nat-Ta(p,x) reactions over 20-3500 MeV, filling a gap in nuclear data.

Findings

Measured 172m2-Hf production cross-sections via gamma-ray spectrometry.

Compared experimental results with multiple nuclear reaction models.

Provided new data for isomeric and ground state production of Hf isotopes.

Abstract

178m2-Hf is an extremely interesting isomeric state due to its potential energy capacity level. One possible way to obtain it is by irradiation of a nat-Ta sample with a high-current proton accelerator. Up to now, there was no information in the international experimental nuclear data base (EXFOR) for this reaction. Irradiations of nat-Ta samples performed for other purposes provide an opportunity to address this question. This paper presents the 172m2-Hf independent production cross-sections determined by gamma-ray spectrometry. The nat-Ta(p,x)172m2-Hf excitation function is studied in the 20-3500 MeV energy range. Comparisons with results by several nuclear models (ISABEL, Bertini, INCL4.5+ABLA07, PHITS, CASCADE07, and CEM03.02) used as event-generators in modern transport codes are also reported. However, since such models are generally not able to separately predict ground and isomeric states of reaction products, only 178-Hf independent and cumulative cross-section data are compared.