# Experimental Determination of Proton Hardness Factors at Several Irradiation Facilities

## TL;DR

This study measures proton hardness factors at three different energies across multiple irradiation facilities to improve the accuracy of radiation damage assessments for detector components in high-energy physics experiments.

## Contribution

It provides new experimental measurements of proton hardness factors at specific energies, validating existing values used in irradiation facilities.

## Key findings

- Measured proton hardness factors: 2.1 at 24 MeV, 2.2 at 23 MeV, 0.62 at 23 GeV.
- Results agree with current hardness factors used at the facilities.
- Enhanced understanding of proton-induced displacement damage in semiconductor sensors.

## Abstract

The scheduled High Luminosity upgrade of the CERN Large Hadron Collider presents new challenges in terms of radiation hardness. As a consequence, campaigns to qualify the radiation hardness of detector sensors and components are undertaken worldwide. The effects of irradiation with beams of different particle species and energy, aiming to assess displacement damage in semiconductor devices, are communicated in terms of the equivalent 1 MeV neutron fluence, using the hardness factor for the conversion. In this work, the hardness factors for protons at three different kinetic energies have been measured by analysing the I-V and C-V characteristics of reverse biased diodes, pre- and post-irradiation. The sensors were irradiated at the MC40 Cyclotron of the University of Birmingham, the cyclotron at the Karlsruhe Institute of Technology, and the IRRAD proton facility at CERN, with the respective measured proton hardness factors being: 2.1 +/- 0.5 for 24 MeV, 2.2 +/- 0.4 for 23 MeV, and 0.62 +/- 0.04 for 23 GeV. The hardness factors currently used in these three facilities are in agreement with the presented measurements.