Abstract
A gamma -activation method for measuring the thickness of thin CsI(TI) polycrystalline 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 multiplicity 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 the backing to its periphery by approximate to 25% for scintillators with a linear size of 140 mm.