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The fast and high efficiency CeBr$_3$ scintillators detectors of the CeBr$_3$ Array (CeBrA) located at the John D. Fox Superconducting Linear Accelerator Laboratory at Florida State University (FSU) are designed for fast-timing spectroscopy in nuclear structure studies. This work presents the fast-timing capabilities of CeBrA in three key experimental configurations: $\gamma$-$\gamma$ coincidences within CeBrA, particle-$\gamma$ coincidences in nuclear reactions using CeBrA and the Super-Enge Split-Pole Spectrograph (SE-SPS), and $\gamma$-conversion electron coincidences with CeBrA and Passivated Implanted Planar Silicon detectors (PIPS).
Each of these configurations provides a unique window into nuclear-structure phenomena. As shown by the CeBrA Demonstrator [1], $\gamma$-$\gamma$ coincidences within CeBrA enable lifetime determination of nuclear levels in the sub-nanosecond regime using the slope and convolution method. Meanwhile, the excellent particle energy resolution of the SE-SPS allows for narrow excitation energy gates, enabling the selective study of the $\gamma$ decay of excited states populated through light-ion induced nuclear reactions with CeBrA. These particle-$\gamma$ coincidences enable the determination of $\gamma$-decay intensities, particle-$\gamma$ angular correlations for assigning spin-parity quantum numbers, and nuclear level lifetimes. Additionally, the combination of CeBrA with PIPS detectors has allowed for $\gamma$-conversion electron coincidences. This configuration allows for the extraction of conversion coefficients and nuclear level lifetimes, thanks to the fast timing capabilities of CeBr$_3$ scintillators.
This work is supported by the U.S. National Science Foundation (NSF) under grant nos. PHY-2012522, PHY-2412808, and PHY-2405485. The material is based upon work supported by the Department of Energy, National Nuclear Security Administration, under Award Number DE-NA0004150, the Center for Excellence in Nuclear Training And University-based Research (CENTAUR). Support by Florida State University is also gratefully acknowledged.
[1] A. L. Conley et al. “The CeBrA demonstrator for particle-$\gamma$ coincidence experiments at the FSU Super-Enge Split-Pole Spectrograph”. In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 1058 (Jan. 1, 2024), p. 168827. issn: 0168-9002. doi: 10.1016/j.nima.2023.168827. url:
https://www.sciencedirect.com/science/article/pii/S0168900223008185
(visited on 01/02/2024).