Experimental techniques to study the $\gamma$ process for nuclear astrophysics at the Cologne accelerator laboratory

TL;DR

This paper details experimental techniques at the Cologne accelerator to measure nuclear reaction cross sections relevant to astrophysics, using advanced spectrometry and recent methodological improvements for precise data collection.

Contribution

It introduces updated experimental setups and methods for measuring low cross sections, validated by commissioning experiments and applied to key astrophysical reactions.

Findings

Validated measurement techniques down to nb cross sections.

Measured cross sections for $^{93}$Nb(p,$$)$^{94}$Mo and compared with previous data.

Demonstrated reliability of the experimental setup through commissioning results.

Abstract

The nuclear astrophysics setup at the Institute for Nuclear Physics, University of Cologne, Germany is dedicated to measurements of total and partial cross sections of charged-particle induced reactions at astrophysically relevant energies. These observables are key ingredients for reaction network calculations of various stellar scenarios, and crucial for the understanding of the nucleosynthesis of elements. The experiments utilize the high-efficiency $\gamma$-ray spectrometer HORUS, and the 10 MV FN-Tandem accelerator. An updated target chamber as well as further experimental methods established in the last years will be presented which allow to measure cross sections down to the nb region. The reliability of the measured cross sections is proven by a $^{89}$Y(p,$\gamma$)$^{90}$Zr commissioning experiment. Additionally, an application for nuclear astrophysics will be presented. The results of a $^{93}$Nb(p,$\gamma$)$^{94}$Mo experiment will be discussed as well as their deviations compared to formerly reported results.