Multianode Photo Multiplier Tubes as Photo Detectors for Ring Imaging Cherenkov Detectors

TL;DR

This study evaluates 64-channel Multianode Photo Multiplier Tubes as potential photo detectors for LHCb RICH detectors, analyzing their efficiency, gain, and magnetic field response through beam tests and light scans.

Contribution

It provides comprehensive performance data of MaPMTs in a RICH detector environment, including spatial efficiency, gain variation, and magnetic field effects.

Findings

High light collection efficiency demonstrated

Performance varies with high voltage settings

MaPMTs show resilience in magnetic fields

Abstract

The 64-channel Multianode Photo Multiplier (MaPMT) has been evaluated as a candidate for the LHCb Ring Imaging Cherenkov (RICH) photo detectors. We present result from data taken with a 3x3 array of closely packed MaPMTs mounted onto the RICH 1 prototype vessel, exposed to charged particle beams at CERN, and read out at LHC speed. Using a LED light source, we have performed spatial light scans to study the light collection efficiency of the MaPMTs We have also measured the performance of the MaPMTs as a function of the applied high voltage. Different dynode resistor chains have been used to study the tubes at low gains. In addition, we have studied the behaviour of the MaPMT in magnetic fields.