2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/85070Hamamatsu photomultiplier tubes (PMT) and various PMT window materials were exposed to gamma irradiation. Tests were performed with absorbed doses of 1 krad and 120 krad. Initial recommendations on PMT types to use in the BTeV electromagnetic calorimeter are stated.11 pages, 14 figures. This work was supported in part by NATO PST Collaborative Linkage Grant "Study of PWO Crystals for BTeV"Instrumentation and Detectorstext