The 75 mm diameter photonis XP43D2 photomultiplier with the screening grid at the anode for timing experiments

Abstract

Requirements given by large scale physics experiments and applications in border security monitoring prompted to upgrade existing large 75 mm and 130 mm diameter PMTs towards better timing properties. First, the existing dynode structure of XP4312 was improved by inserting a screening grid in front of the anode, following that applied to the XP20D0. The performance of the new XP43D2 photomultiplier was studied in comparison to XP4312 PMT. The time jitter of the new PMT was measured using a fast light pulser based on an XP22 light emitting diode. The timing properties in coincidence experiments were measured with large NaI(Tl) and plastic scintillators for 60 Co and 22 Na gamma rays and discussed in terms of the measured photoelectron numbers.

Fast photomultipliers for TOF PET

“…The normalized time resolution of 10.3 x10 3 ps phe is close to that measured with the XP20D0 due to a better time jitter of 380 ps. The same XP1020 PMT, equipped with the screening grid at the anode, should give improvement in time resolution by a factor of 1.2, just like presented here for 2 inch XP2020 [2] or for 3 inch XP4312 in [27]. Thus, a value of 8.6 x10 3 ps phe seems to be realistic and gives the time resolution equal to about 170 ps.…”

Comparative Study of Large NaI(Tl) and BGO Scintillators for the EURopean Illicit TRAfficking Countermeasures Kit Project

“…The design of venetian-blind dynodes introduces a large time spread that was also observed in the slow rise time of anode pulse of several tenths of nanoseconds. A significant improvement in the timing performance of the BGO equipped detector can be achieved by fitting it with the Photonis XP45D2B PMT with a greenextended photocathode and the screening grid mounted at the anode [19].…”