CSI(T1) FILM SCINTILLATORS WITH A LARGE-AREA

CsI(Tl) film scintillators 20-25 mg/cm2 thick with areas of approximat ely 150 cm2 prepared by vacuum deposition were investigated. The scint illators have a light yield close to that of a CsI(Tl) single crystal. The amplitude resolution was measured for 83 specimens under alpha-ir radiation from a collimated ThC' alpha-source and ranged from 12 to 20 % in the main. When the entire scintillator is mounted on a conical li ght guide and irradiated by alpha-particles, the resolution is approxi mately half as much because the light transmittance of the light guide depends on the flash position. The half-intensity thickness for the s cintillator's intrinsic emission is 16-20 mg/cm2. The depth of the sur face dead layer is no more than 1 mg/cm2. The light yield for differen t detected particles with different energies (He-4, Li-6, and N-14 wit h maximum energies of 60, 80, and 70 MeV, respectively) was studied. T he results are consistent with the data reported for single-crystal sc intillators.