YAP:Ce SCINTILLATION DETECTOR FOR TRANSMISSION MEOSSBAUER SPECTROSCOPY

摘要

A YAP:Ce scintillation crystal has a decay time that is one order of magnitude shorter than that of NaI:Tl, and therefore this allows its use for rather high counting rates. The optimal thickness of a YAP:Ce crystal for ~(57)Fe and ~(119)Sn Moessbauer spectroscopy is 0.35 mm. The photomultiplier tube R6095 (Hamamatsu) is used in the scintillation detector. The signal is amplified by means of a fast preamplifier constructed on the base of a NE 5539 operational amplifier. Standard pulse-height discriminators, used with the NaI:T1 scintillation detector and proportional counter, respectively, cannot be used with a YAP:Ce scintillation detector, because the duration of the pulses on the preamplifier output is less than 200 ns. A fast pulse-height discriminator was built using two fast MAC 160 comparators.