Application of CeBr$_3$ Scintillator Crystals for Sub-Nanosecond Lifetime Measurements

Ongoing efforts in the development of next generation radiation detectors has yielded several new scintillation crystals with gamma ray detection properties superior to more traditional materials. Amongst these so-called ``super'' scintillators is CeBr$_3$, which exhibits fast timing properties similar to that of LaBr$_3$ and BaF$_2$, as well as excellent energy resolution. The time resolution of CeBr$_3$ detectors has been found to be as low as 120 ps in coincidence measurements. We are currently investigating the use of CeBr$_3$ detectors for research in basic and applied nuclear physics involving fast timing measurements. In the work presented here, a pair of CeBr$_3$ detectors have been used to directly measure the half-life of a 1.48 ns isomer in $^{152}$Sm using the delayed coincidence technique and a multi-parameter data acquisition system. Further work is underway to apply this method for measuring sub-nanosecond lifetimes in isotopes created through thermal neutron capture at the UMass Lowell research reactor.