A study on light collection of small scintillating crystals

Mesurements are described concerning the light collection efficiency of YAP :Ce and CsI(T1) crystals pillars with thicknesses ranging between 3 and 28 mm and cross-sections of 0.6 x 0.6 and 1 x 1 mm(2). These measurements have shown that the light collection is strongly dependent on the length of the pillar rather than on its cross-sectional area. A Monte Carlo code has bee n developed in order to evaluate the light collection efficiency as a funct ion of the pillar geometry and surface treatment. Particular attention has been paid to the light transition through the crystal-photocathode window i nterface. The possibility to improve light detection by using a new photon detector provided with a YAP photocathode window has been verified. (C) 200 0 Published by Elsevier Science B.V. All rights reserved.