Activation cross section measurement of the 100Mo(α,n)103Ru reaction for optical potential studies

T.N Szegedi,P Mohr,Gy Gyürky,G.G Kiss

doi:10.1088/1742-6596/1668/1/012041

Abstract

The light neutron-rich nuclei can be synthesized via (α,n) reactions in the so-called weak r-process. The abundances of these species are derived using reaction network calculations. Such a simulation has astrophysical and nuclear physics inputs, one of the most uncertain parameter is the α-nucleus optical potential. (α,n) cross section measurements can be used to evaluate α-optical potentials. For this purpose, the activation cross section measurement of the 100Mo(α,n)103Ru reaction is in progress at Atomki.

Highlights

The synthesis of the heavy elements beyond iron is dominantly driven by neutroncapture reactions [1, 2]
The neutron-rich nuclei between 56Fe and 109Ag can be synthesized in a neutrino-driven wind following the birth or merge of neutron stars in the weak r-process [3, 4]
The network relies on astrophysical inputs — such as the temperature of the astrophysical site, the timescale of the process, the initial isotopic abundances etc. — and nuclear physics inputs like the reaction rates

Summary

Introduction

The synthesis of the heavy elements beyond iron is dominantly driven by neutroncapture reactions [1, 2]. The neutron-rich nuclei between 56Fe and 109Ag can be synthesized in a neutrino-driven wind following the birth or merge of neutron stars in the weak r-process [3, 4]. The cross sections need to be measured at low energies where the predictions, calculated using different α-OMP’s, are reasonably different. Such experiments are typically carried out using the activation technique. By carrying out a new cross section measurement using thick molybdenum targets, a more precise database can be obtained and this reaction can be used to evaluate the α-OMPs used in weak-r process calculations. The activation cross section measurement of the 100Mo(α,n)103Ru reaction in the 7.9 MeV ≤ Eα ≤ 13.0 MeV energy range is in progress at Atomki using natural isotopic composition targets

Activity measurement

Determination of the detection efficiency

Findings

Outlook