Discriminant Analysis and Secondary-Beam Charge Recognition

TL;DR

This paper presents a discriminant-analysis method to improve secondary-beam charge recognition in nuclear experiments, achieving about 90% efficacy and enhancing previous scalar methods by 20%.

Contribution

The paper introduces a multivariate discriminant-analysis approach for charge recognition, significantly improving accuracy in projectile fragmentation experiments.

Findings

Charge recognition efficacy increased to about 90%.

Discriminant analysis outperforms simple scalar methods by 20%.

Method applied successfully in relativistic secondary beam experiments.

Abstract

The discriminant-analysis method has been applied to optimize the exotic-beam charge recognition in a projectile fragmentation experiment. The experiment was carried out at the GSI using the fragment separator (FRS) to produce and select the relativistic secondary beams, and the ALADIN setup to measure their fragmentation products following collisions with Sn target nuclei. The beams of neutron poor isotopes around 124La and 107Sn were selected to study the isospin dependence of the limiting temperature of heavy nuclei by comparing with results for stable 124Sn projectiles. A dedicated detector to measure the projectile charge upstream of the reaction target was not used, and alternative methods had to be developed. The presented method, based on the multivariate discriminant analysis, allowed to increase the efficacy of charge recognition up to about 90%, which was about 20% more than achieved with the simple scalar methods.