Thickness measurements of thin CsI(Tl) scintillators

A gamma -activation method for measuring the thickness of thin CsI(TI) poly crystalline films deposited by evaporation on large-area (similar to 150 cm (2)) backings is described. Scintillators specially prepared to be used in the FASA installation as detectors of intermediate-mass fragment multiplici ty were measured. It was shown that the distribution of the film thickness along the scintillator surface can be determined by beta -activity scanning . It has been shown that the film thickness decreases from the middle of th e backing to its periphery by approximate to 25% for scintillators with a l inear size of 140 mm.