Dose rate effects in the radiation damage of the plastic scintillators of the CMS Hadron Endcap Calorimeter

TL;DR

This study investigates how different dose rates of radiation affect the damage to plastic scintillators used in the CMS detector, revealing that lower dose rates cause more significant light output reduction, consistent with diffusion-based models.

Contribution

It provides new measurements of dose rate effects at very low dose rates, confirming and extending previous findings with stronger effects observed.

Findings

Lower dose rates cause greater damage for the same dose

Results align with diffusion-based damage models

Damage increases with decreasing dose rate

Abstract

We present measurements of the reduction of light output by plastic scintillators irradiated in the CMS detector during the 8 TeV run of the Large Hadron Collider and show that they indicate a strong dose rate effect. The damage for a given dose is larger for lower dose rate exposures. The results agree with previous measurements of dose rate effects, but are stronger due to the very low dose rates probed. We show that the scaling with dose rate is consistent with that expected from diffusion effects.