Temperature dependence of pure CsI:: scintillation light yield and decay time

The temperature dependence of the light emission for pure CsI crystals has been measured with photomultipliers, and photodiodes with wavelength shifters from 80-300 K. The light yield at 80 K is N-y = 50,000+/-5000 photons/MeV. This number was deduced from the number of electron-hole pairs produced in the photodiode, N-eh = 39,600+/-1200. The light yield at room temperature is lower by a factor of 15.8+/-1.0, giving 3200+/-400 photons/MeV. Decay times were measured with a photomultiplier. At room temperature two fast decay components were observed with decay times of 6+/-1 and 28+/-2 ns. Below 180 K only one component is observed and at 80 K the decay time is 1015+/-17 Its. (C) 2002 Elsevier Science B.V. All rights reserved.