A CsI(T1)-PIN photodiode gamma-ray probe

We characterize two single elements,consisting of 10 x 10 x 5 and 5 x 5 x 5 mm(3) scintillator crystals read out by 10 x 10 mm(2) PIN silicon photodiode. The photodiode signal is amplified by. an ultra-low-noise preamplifier and a pulse shape amplifier. The photodiode has a low leakage current (<1 nA) and a small capacitance for electronic noise minimization. This probe demonstrates, at room temperature, an energy resolution of 15% for 140 keV gamma rays and 8.38% for 365 keV. Detection efficiency of a Co-57 source placed at a distance of 1 cm is 250 counts s(-1) mu Cu-1. Furthermore, the detector compactness, its low sensitivity to magnetic fields and the low-voltage power supply are very useful features for per-operative use. (C) 2003 Elsevier Science B.V. All rights reserved.