Performance of Photosensors in a High-Rate Environment for Gas Cherenkov Detectors

Authors

Abstract

The solenoidal large intensity device (SoLID) at Jefferson Lab will push the boundariesof luminosity for a large-acceptance detector, which necessitates the use of a light-gas thresholdCherenkov counter for online event selection. Due to the high luminosity, the single-photonbackground rate in this counter can exceed 160 kHz/cm2at the photosensors. Therefore, it isessential to validate the high-rate limits of the planned photosensors and readout electronics inorder to mitigate the risk of failure. We report on the design and an early set of studies carried outusing a small telescopic Cherenkov device in a high-rate environment up to 60 kHz/cm2, in Hall Cat Jefferson Lab. Commercially available multi-anode photomultipliers (MaPMT) and low-costlarge-area picosecond photodetectors (LAPPD) were tested using the JLab FADC250 modules forreadout. The test beam results show that the MaPMT array and the internal stripline LAPPD candetect and identify single-electron and pair-production events in high-rate environments. Due toits higher quantum efficiency, the MaPMT array provided a better separation between the singleelectron and the pair-production events compared to the internal stripline LAPPD. A GEANT4simulation confirms the experimental performance of our telescopic device.