Experimental determination of proton hardness factors at several irradiation facilities

Abstract

A: 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.

Bistability of the BiOi complex and its implications on evaluating the “acceptor removal” process in p-type silicon

“…For determining eq a hardness factor of 0.62 was considered [28]. These pad diodes were investigated by means of Deep Level Transient Spectroscopy (DLTS), after injecting only holes or both electrons and holes with filling pulses ranging from 1 ns to 10 s. By using same vendors and processing of all diodes while performing all the experiments in the same place, with the same set-up/procedures the study performed on EPI diodes becomes relevant for studying the dependencies of gBiOi on boron doping, on fluence and type of irradiation, for samples with the same Carbon content.…”

Analysis of Proton Radiation-induced Effects on Polymer-based Relative Humidity Sensor

“…where, for the 24 GeV /c proton beam, the estimation of the hardness factor from the experimental measurements is κ = 0.62 ± 0.04 32 .…”

Depth-dependent charge collection profile of pad diodes

“…Two diodes with the size of 5.0 × 5.0 mm 2 were irradiated to 1 MeV neutron equivalent fluences Φ eq of 2 × 10 15 cm −2 and 4 × 10 15 cm −2 , and two diodes with the size of 2.5 × 2.5 mm 2 were irradiated to Φ eq of 8 × 10 15 cm −2 and 12 × 10 15 cm −2 . For determination of Φ eq , a hardness factor of κ = 2.2 is used [10]. From the capacitance-voltage measurement, the depletion voltage of the non-irradiated diode was determined to be around 75 V and the doping density of the bulk region is 4.5 × 10 12 cm −3 .…”