Scintillator Tile Batch Test of CEPC AHCAL

TL;DR

This paper presents a comprehensive batch testing platform for scintillator tiles used in the CEPC AHCAL, demonstrating high qualification rates and uniform light yield essential for detector performance.

Contribution

It introduces an automated 144-channel batch test system and reports on the qualification results for over 15,000 scintillator tiles for CEPC AHCAL.

Findings

Over 91.6% of tiles qualified within 10% light yield variation

Measured light yield around 12.9 photoelectrons per tile

Automated testing platform improves quality control efficiency

Abstract

Hadron calorimeter (HCAL) is an essential sub-detector of the baseline detector system for Circular Electron Positron Collider (CEPC). We plan to build an Analog Hadron CALorimeter (AHCAL) prototype based on the Particle Flow Algorithm (PFA). The AHCAL of CEPC uses steel as absorber and scintillator tiles read out by Silicon Photo-Multipliers (SiPMs) as sensitive medium. The energy linearity and resolution of the calorimeter depends on the light yield uniformity of sensitive medium. It is essential to qualify the entire detector production in order to select scintillator tiles with light yield uniform within 10\%. An automated batch test platform has been designed with 144 channels, an automated 3D servo motor. The paper summarizes the tests performed on more than 15000 scintillator tiles. The measured light yield, corrected for the set-up response non-uniformity, is around 12.9 p.e. . About 91.6\% of scintillators (14219 pieces) are qualified within 10\% of light yield window.