Photo-nuclear cross sections on \(^{197}\)Au, an update on the gold standard

A method was developed for measuring photonuclear reactions concurrently at several discrete photon beam energies on a stack of different target materials via a single irradiation. Concentric ring targets of the materials (in order from front to back targets: Au, TiO\(_2\), Zn, Os, and Au) were irra...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2024-11
Main Authors: Song, J, Rotsch, D, Nolen, J A, Gampa, R, de Kruijff, R M, Brossard, T, Howell, C R, Krishichayan, F, Wu, Y K, Mikhailov, S, Ahmed, M W, Janssens, R V F
Format: Article
Language:English
Subjects:
Excitation
Gamma ray sources
Internal conversion
Irradiation
Nuclear cross sections
Photon beams
Photon scatter
Photons
Photonuclear reactions
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A method was developed for measuring photonuclear reactions concurrently at several discrete photon beam energies on a stack of different target materials via a single irradiation. Concentric ring targets of the materials (in order from front to back targets: Au, TiO\(_2\), Zn, Os, and Au) were irradiated at the High Intensity Gamma-ray Source (HI\(\gamma\)S). As a proof of principle, we report the result of the cross section measurements from the front Au target. The excitation functions of the \(^{197}\)Au(\(\gamma\),n)\(^{196}\)Au and \(^{197}\)Au(\(\gamma\),3n)\(^{194}\)Au reactions were determined in the incident photon energy range of 13-31 MeV using quasi-monoenergetic photon beams provided at HI\(\gamma\)S. The cross sections of the combined ground state (2\(^{-}\)) and short-lived first isomeric state (m1, 5\(^{+}\)), and of the second isomeric state (m2, 12\(^{-}\)) in the \(^{196}\)Au production are obtained separately by subtracting the \(\gamma\) rays from the internal conversion of the second isomeric state. The excitation function of the second isomeric state via the photon-induced reaction \(^{197}\)Au(\(\gamma\),n)\(^{196m2}\)Au was measured for the first time. By using the activation method rather than direct neutron counting, the exclusive cross sections for the (\(\gamma\),n) and (\(\gamma\),3n) reactions were determined. Comparing the yields from the front and back gold targets validates our ability to simulate the effect of photon scattering in the target stack and provides a method for assessing the systematic uncertainty of our technique.
ISSN:2331-8422