The radiation hardness of a Phi(sic)Y- 115 photomultiplier (PMT) with
photocathode windows of C96-1 glass; alloyed-type dynode systems; and
PMT input windows of MgF2, C95-2, C50, and radiation-hard C96-1 glasse
s was studied. The transparency of the C96-1 glass photocathode window
s, the Phi(sic)Y-115 PMT signals, and the gain of the alloyed-type dyn
ode systems were observed to be unaffected by radiation at doses up to
35, 15, and 100 Mrad, respectively.