Simulating Multi-channel Vacuum Phototriodes using COMSOL

Abstract

Vacuum phototriodes have been used for a number of years in particle physics experiments. For 10 example, they were used in the OPAL experiment at LEP and are currently used in the endcap calorimeter of the CMS experiment at CERN’s Large Hadron Collider. A simulation of a CMS vacuum phototriode (RIE type FEU-188) has been implemented using the COMSOL multi-physics software environment. In addition, a new vacuum phototriode configured with a segmented anode, to provide four independent channels within the same overall device envelope, is presented. The induced signal as a function of time, and the effects of cross-talk in adjacent quadrants have been studied