A visualization of the damage in Lead Tungstate calorimeter crystals after exposure to high-energy hadrons

TL;DR

This paper investigates the damage mechanisms in Lead Tungstate calorimeter crystals caused by high-energy hadrons, providing visualizations and insights crucial for future detector performance at the HL-LHC.

Contribution

It presents the first direct visualization of hadron-specific damage in Lead Tungstate crystals after exposure to 24 GeV/c protons, elucidating the underlying damage process.

Findings

Damage is cumulative and related to transparency loss

Visual evidence of hadron-specific damage mechanisms

Implications for calorimeter performance at HL-LHC

Abstract

The anticipated performance of calorimeter crystals in the environment expected after the planned High-Luminosity upgrade of the Large Hadron Collider (HL-LHC) at CERN has to be well understood, before informed decisions can be made on the need for detector upgrades. Throughout the years of running at the HL-LHC, the detectors will be exposed to considerable fluences of fast hadrons, that have been shown to cause cumulative transparency losses in Lead Tungstate scintillating crystals. In this study, we present direct evidence of the main underlying damage mechanism. Results are shown from a test that yields a direct insight into the nature of the hadron-specific damage in Lead Tungstate calorimeter crystals exposed to 24 GeV/c protons.