Test of a new 64-channel PMT for imaging

Abstract The introduction of a new photodetector, the XP4702, supplements and updates the conventional RTC ∗ photomultiplier range. A new technological concept of plane and parallel dynodes has made it possible to produce a compact large area electron multiplier with good gain and uniformity. This technique paves the way for multichannel PMs capable of imaging with a spatial resolution from 0.5 to several millimetres, midway between those of microchannel image intensifiers and arrays of small (XP1911 (RTC) or R1635 (HTV) type PMs. Mosaic techniques then make it possible to produce photodetectors capable of imaging individual photons in the visible and UV part of the spectrum over areas approaching 1 m 2 , with high time, spatial and dynamic performance. After a brief description of the tube and an account of its mode of operation, we describe some of its chief characteristics. Finally, we suggest some desirable lines of development.