The CeBrA demonstrator for particle-y coincidence experiments at the FSU Super-Enge Split-Pole Spectrograph

We report on a highly selective experimental setup for particle-y coincidence experiments at the Super-Enge Split-Pole Spectrograph (SE-SPS) of the John D. Fox Superconducting Linear Accelerator Laboratory at Florida State University (FSU) using fast CeBr3 scintillators for y-ray detection. Specifically, we report on the results of characterization tests for the first five CeBr3 scintillation detectors of the CeBr3 Array (CeBrA) with respect to energy resolution and timing characteristics. We also present results from the first particle-y coincidence experiments successfully performed with the CeBrA demonstrator and the FSU SE-SPS. We show that with the new setup, y-decay branching ratios and particle-y angular correlations can be measured very selectively using narrow excitation energy gates, which are possible thanks to the excellent particle energy resolution of the SE-SPS. In addition, we highlight that nuclear level lifetimes in the nanoseconds regime can be determined by measuring the time difference between particle detection with the SE-SPS focal-plane scintillator and y-ray detection with the fast CeBrA detectors. Selective excitation energy gates with the SE-SPS exclude any feeding contributions to these lifetimes.

Automated summary

We present a highly selective experimental setup for particle-γ coincidence experiments using fast CeBr3 scintillators for γ-ray detection at the Super-Enge Split-Pole Spectrograph (SE-SPS) of the John D. Fox Superconducting Linear Accelerator Laboratory at Florida State University (FSU). The characterization tests of the first five CeBr3 scintillation detectors of the CeBr3 Array (CeBrA) regarding energy resolution and timing characteristics are reported. The results of the first particle-γ coincidence experiments successfully performed with the CeBrA demonstrator and the FSU SE-SPS are also presented. It is demonstrated that the new setup allows for very selective measurements of γ-decay branching ratios and particle-γ angular correlations using narrow excitation energy gates, facilitated by the excellent particle energy resolution of the SE-SPS. Moreover, the determination of nuclear level lifetimes in the nanoseconds regime is highlighted by measuring the time difference between particle detection with the SE-SPS focal-plane scintillator and γ-ray detection with the fast CeBrA detectors. The selective excitation energy gates with the SE-SPS exclude any feeding contributions to these lifetimes.