Silicon Photomultipliers for Orbital Ultra High Energy Cosmic Ray Observation

TL;DR

This paper demonstrates the viability of Silicon Photomultipliers (SiPMs) as replacements for traditional photomultiplier tubes in cosmic ray detection, highlighting technical development, characterization methods, and improved uniformity in sensor arrays.

Contribution

It introduces a new sensor readout system using Citiroc ASICs and FPGA control, and presents methods for sensor characterization and biasing to enhance detector performance.

Findings

SiPMs are viable for high luminosity cosmic ray detection.

The developed readout system processes 128-channel events effectively.

Channel-specific biasing improves detector uniformity.

Abstract

Development of the Silicon photomultiplier Elementary Cell Add-on camera (SiECA) has provided extensive information regarding the use of SiPMs for future cosmic ray detection systems. We present the technical aspects of sensor readout development utilizing Citiroc ASIC chips from Weeroc controlled by a Xilinx FPGA to process and package events from four 64 channel Hamamatsu MPPC S13361 arrays generating 128 frame events with an integration time of 2.5ms (parameters are based on JEM-EUSO geometry but can be easily adjusted). With single photon counting capability, SiECA proves SiPM are viable sensors to replace Multi-Anode PhotoMultiplier Tubes in future devices, especially when high luminosity exposure is possible potentially damaging MAPMT based systems. Complementary to the technical aspects, computational and analysis methods for sensor array characterization and in depth device flat-fielding are presented. Provided channel by channel biasing, in comparison to uniform biasing with MAPMTs, fine tuning of operating parameters with MPPC arrays allows for substantial improvements in detector and signal uniformity.