Study of $\boldsymbol{(\alpha,p)}$ and $\boldsymbol{(\alpha,n)}$ reactions with a Multi-Sampling Ionization Chamber

TL;DR

This paper introduces a novel active target technique using the MUSIC detector to measure $(oldsymbol{ extalpha,p})$ and $(oldsymbol{ extalpha,n})$ reactions over a wide energy range, verified through multiple reaction measurements.

Contribution

The work demonstrates a new method with the MUSIC detector for simultaneous measurement of multiple nuclear reactions in inverse kinematics.

Findings

Good agreement with previous cross section measurements for $^{17}$O$( extalpha,n)$^{20}$Ne.

Successful simultaneous measurement of $^{23}$Na$( extalpha,p)$^{26}$Mg and $^{23}$Na$( extalpha,n)$^{26}$Al.

Extended the excitation function range from 2 to 6 MeV in the center of mass.

Abstract

A large number of $(\alpha,p)$ and $(\alpha,n)$ reactions are known to play a fundamental role in nuclear astrophysics. This work presents a novel technique to study these reactions with the active target system MUSIC whose segmented anode allows the investigation of a large energy range of the excitation function with a single beam energy. In order to verify the method, we performed a direct measurements of the previously measured reactions $^{17}$O$(\alpha,n)^{20}$Ne, $^{23}$Na$(\alpha,p)^{26}$Mg, and $^{23}$Na$(\alpha,n)^{26}$Al. These reactions were investigated in inverse kinematics using $^{4}$He gas in the detector to study the excitation function in the range of about 2 to 6 MeV in the center of mass. We found good agreement between the cross sections of the $^{17}$O$(\alpha,n)^{20}$Ne reaction measured in this work and previous measurements. Furthermore we have successfully performed a simultaneous measurement of the $^{23}$Na$(\alpha,p)^{26}$Mg and $^{23}$Na$(\alpha,n)^{26}$Al reactions.