Research on Particle Identification of In-ring Reaction Spectrometer at HIRFL-CSR

In research related to nuclear isoscalar giant resonances, α particle is a effective probe because of the scalar-isoscalar nature of the α particle. In the experiment, δ electrons interfere with the detection of recoil light particles. In order to identify low-energy α particles and electrons in the in-ring reaction within the HIRFL-CSR, researchers used the direct fitting method to analyze the waveform signals of α particles and electrons generated in silicon detectors, and conducted confirmatory experiments using ²⁰⁷Bi sources and ²⁴¹Am sources. The experimental results indicate that, after removal, the number of electrons accounted for 46.5% of the total electrons, and when combined with the coincidence selection, the proportion of electrons removed was 54.9%. This procedure can effectively remove electron signals mixed into the α-particle signals, thereby helping to eliminate background noise in in-ring nuclear reaction experiments.