Reconstruction of Fission Events in Heavy Ion Reactions with CSHINE

TL;DR

This paper presents a method to reconstruct fast fission events in heavy ion reactions using measurements from CSHINE, revealing dynamic features of fission through velocity and angular distributions.

Contribution

It introduces a novel reconstruction technique for fast fission events in heavy ion collisions using velocity and timing data from CSHINE detectors.

Findings

Velocity distribution broadening decreases with folding angle.

Azimuthal difference of fragments reduces with folding angle.

Fission axis distribution indicates dynamic behavior.

Abstract

We report the reconstruction method of the fast fission events in 25 MeV/u $^{86}$Kr +$^{208}$Pb reactions at the Compact Spectrometer for Heavy IoN Experiment (CSHINE). The fission fragments are measured by three large-area parallel plate avalanche counters, which can deliver the position and the arrival timing information of the fragments. The start timing information is given by the radio frequency of the cyclotron. Using the velocities of the two fission fragments, the fission events are reconstructed. The broadening of both the velocity distribution and the azimuthal difference of the fission fragments decrease with the folding angle, in accordance with the picture that fast fission occurs. The anisotropic angular distribution of the fission axis also reveals consistently the dynamic feature the fission events.