Studies of position sensitive photomultipliers for scintillating and waveshifting fiber readout I

Results of evaluation studies of one of four tested types of multianode (or multidynode) photomultipliers are presented. Operation parameters such as quantum efficiency, uniformity of response, amplification factors, position resolution and, most importantly, cross-talk effects were studied for a Philips XP4722 by injecting short light pulses producing on the average from one to 10 photoelectrons. An injecting fiber of 1-mm diameter was mounted on a two-dimensional computer-controlled precision scanner, and the response was measured for each fiber position. Limitations and possible improvements are discussed. It is noted that even the best presently available multielement position-sensitive photomultipliers suffer from effects of interelement cross-talk, which limit their use.<>