Performance of photosensors in a high-rate environment for gas Cherenkov detectors

TL;DR

This study evaluates the performance of different photosensors, including MaPMTs and LAPPDs, in high-rate environments relevant for gas Cherenkov detectors at Jefferson Lab, demonstrating their capabilities and limitations for online event detection.

Contribution

The paper presents experimental validation of MaPMT and LAPPD photosensors' performance under high-rate conditions up to 60 kHz/cm² for gas Cherenkov detectors.

Findings

MaPMT array shows superior event separation due to higher quantum efficiency.

Both MaPMT and LAPPD can detect single-electron and pair-production events.

GEANT4 simulation confirms experimental results.

Abstract

The solenoidal large intensity device (SoLID) at Jefferson Lab will push the boundaries of luminosity for a large-acceptance detector, which necessitates the use of a light-gas threshold Cherenkov counter for online event selection. Due to the high luminosity, the single-photon background rate in this counter can exceed 160 kHz/cm$^2$ at the photosensors. Therefore, it is essential to validate the high-rate limits of the planned photosensors and readout electronics in order to mitigate the risk of failure. We report on the design and an early set of studies carried out using a small telescopic Cherenkov device in a high-rate environment up to 60 kHz/cm$^2$, in Hall C at Jefferson Lab. Commercially available multi-anode photomultipliers (MaPMT) and low-cost large-area picosecond photodetectors (LAPPD) were tested using the JLab FADC250 modules for readout. The test beam results show that the MaPMT array and the internal stripline LAPPD can detect and identify single-electron and pair-production events in high-rate environments. Due to its higher quantum efficiency, the MaPMT array provided a better separation between the single-electron and the pair-production events compared to the internal stripline LAPPD. A GEANT4 simulation confirms the experimental performance of our telescopic device.