Dual parameter analysis of CsI : Tl/PMT with a digital oscilloscope

Scintillation pulses from alpha-particle and gamma-ray excited CsI:T1 were recorded with a photomultiplier tube and digital oscilloscope card in singl e parameter (pulse shape or pulse height) and dual parameter (simultaneous pulse shape and pulse height) modes. A 2.8 x 1.3 x 1.3 cm(3) CsI:T1 crystal was coupled to a Burle 8850 photomultiplier tube (PMT) and excited with Gd -148 (E-alpha = 3.18 MeV) and Cs-137 (E-gamma = 0.662 MeV). The timing puls es (50 Omega terminated dynode signal) from the PMT base were directly inpu t to a GaGe CompuScope 8012A/PCITM (12-bit, 50 MHz dual channel digital osc illoscope card) that resided in a P6-300 MHz personal computer. Individual digitized pulses were processed via a LabVIEW(TM) V 4.1 interface to the os cilloscope. The ratio of the charge collected over a short time interval to the total charge collected was used for the single parameter pulse shape s pectrum while the total charge collected was used for the single parameter pulse height spectrum. The dual parameter spectrum was produced by displayi ng the pulse shape and pulse height information for individual pulses on a 2-D grid. The digital oscilloscope with LabVIEW(TM) interface offers a vers atile data acquisition system for pulse shape, pulse height and dual-parame ter analyses. (C) 1999 Elsevier Science B.V. All rights reserved.