The use of scintillating fiber detectors, read out with silicon photomultiplier (SiPM) arrays, has emerged as a promising technology for particle tracking in high-energy physics, cosmic-ray and gamma-ray astrophysics. We are working on the Fiber Tracker (FIT), proposed for the upcoming High Energy Cosmic-Radiation Detection (HERD) facility. FIT provides excellent spatial resolution and charge measurements. To read out the SiPMs, we use a custom chip called BETA, designed to meet strict requirements for space — low noise, good linearity, and low power.
At IFAE, we’ve been testing this readout system using an LED setup to make sure it works across a wide range of particle energies — from minimum ionizing particles up to heavy nuclei like iron. The system automatically switches gain settings to avoid saturation at high signals, and we’ve fine-tuned trigger thresholds to keep noise low.
I’ll present how we optimized and calibrated the system with the LED, how the auto-gain operation works, and what we’ve learned from lab tests and CERN beam test campaigns.
Giada Caneva, Elia Bertoldo, Francesco Sciotti