Development of a LaBr₃(Ce) Fast-timing Array for FAIR

Abstract

Abstract. A γ-ray spectrometer with fast-timing capabilities, constructed of LaBr 3 (Ce:5%) detectors, is under development for use at the future Facility for Anti-proton and Ion Research (FAIR). The physics aims of this device are to measure the half-lives of excited states in the region of ∼50 ps to several ns, in exotic nuclei. Monte-Carlo simulations using the GEANT4 software package have determined the final design of this fasttiming array by calculating the full-energy peak efficiencies of several different detector geometries. The results of the simulated efficiencies for each configuration were used to calculate the timing precision. Consequently, an array of thirty six, ø3.8x5.1 cm cylindrical crystals was found to be the optimum configuration. The detectors were purchased and subsequently characterised, with each detector found to have intrinsic energy and timing resolutions of ∼ 2.8 % (FWHM) and ∼ 210 ps (FWHM) for the 1173 and 1332 keV decays from 60 Co.

Configurations and hindered decays of K isomers in deformed nuclei with A>100

“…[150,151]). A number of developments incorporating arrays of such detectors in new facilities are progressing [152,153], but most (preparatory) measurements to date have been aimed at low-lying, collective states within rotational bands [150,151,154] or at specific states in spherical nuclei [153].…”