Overview

This project was carried out as part of a 3-week internship during my third year of Physics at Université Grenoble Alpes, at the Laboratory of Subatomic Physics and Cosmology (LPSC). It focused on the performance study of silicon analog sensors used in the FoCal electromagnetic calorimeter (an upgrade of the ALICE experiment at CERN, scheduled for 2029).

About the ALICE Experiment

The ALICE (A Large Ion Collider Experiment) is one of the major experiments at the Large Hadron Collider (LHC) at CERN. Its primary goal is to study the Quark-Gluon Plasma (QGP), a state of matter that existed microseconds after the Big Bang.

Experimental Setup

A test bench was installed at LPSC to characterize the detector response using cosmic muons. The setup included:

• A single silicon pad read out by an HGCROC chip
• Two plastic scintillators in coincidence mode to trigger on cosmic muons
• A system to scan the delay timing between the pad and trigger signals

Key Results

Key findings from the study:

• Clear separation between muon signals and pedestal using ADC histograms
• Successful modeling of the pedestal with a Gaussian distribution
• Muon peak characterization using Landau distribution
• Average gain measurement: 1.84 ± 0.13 fC

Conclusion

This internship provided valuable hands-on experience with experimental high-energy physics, from detector instrumentation to data acquisition and analysis. The results contribute to the ongoing development of the FoCal detector for the ALICE experiment upgrade.