Performance of a Charged Particle Detector System to Study Unbound Systems at FRIB

Detections of charged fragments and neutrons emitted from neutron-unbound systems are made more complicated by the possibility of coincidentally detecting the gamma rays emitted from long-lived excited states of the final charged fragment. A charged particle detector telescope system was specifically developed to enable detection of such charged particles, along with the emitted neutrons and gamma rays, in a compact arrangement. This system was used for the study of such a nuclear system, ¹³Be, in an experiment that was performed at the National Superconducting Cyclotron Laboratory on the campus of Michigan State University. The charged particles were identified after passing through one silicon position sensitive detector (140 μm thick) and a stack of silicon detectors (5 × 500 μm thick) for energy loss measurement with a CsI crystal (3 cm thick) to measure the total kinetic energy of the isotopes. The latter was equipped with a read out by a silicon pin diode. Neutrons passed through the detectors with minimal attenuation and were detected by the MoNA-LISA modular neutron array. The emitted gamma rays were measured in an almost 4p solid angle around the CsI crystal using the CAESAR detector. The charged particle detector signals were processed using a digital data acquisition system. This talk will discuss the current analysis of this Si-CsI telescope data.