LaBr/sub 3/:Ce scintillators for gamma ray spectroscopy

Abstract

In this paper, we report on a relatively new scintillator - LaBr/sub 3/ for gamma ray spectroscopy. Crystals of this scintillator have been grown using Bridgman process. This material when doped with cerium has high light output (/spl sim/60,000 photons/MeV) and fast principal decay constant (/spl les/25 ns). Furthermore, it shows excellent energy resolution for /spl gamma/-ray detection. Energy resolution of 3.2% (FWHM) has been achieved for 662 keV photons (/sup 137/Cs source) at room temperature. High timing resolution (260 ps FWHM) has been recorded with LaBr/sub 3/-PMT and BaF/sub 2/-PMT detectors operating in coincidence mode using 511 keV positron annihilation /spl gamma/-ray pairs. Details of its scintillation properties, and variation of these properties with changing cerium concentration are reported. Potential applications of this material are also addressed.