Stability of spectrometric characteristics of CsI:Tl detectors depending on the surface treatment method

The influence of various mechanochemical methods used to treat the entrance surface of a CsI:Tl scintillator on the specific light output and the pulse-height resolution during detection of α particles with energies of 2 or 5 MeV is described. Nonlinearity between the light output and the energy of α particles increases from 7% for a polished surface to 35% after grinding, which leads to a degraded pulse-height resolution. A method for treating the CsI:Tl surface is proposed that minimizes the light-output nonlinearity and ensures stability of spectrometric characteristics in time.