# Characterization of a 100 nm RADFET as a Proton Beam Detector

## TL;DR

This study tests a RADFET device as a proton beam detector, showing it is highly accurate and stable for high-dose applications like spacecraft.

## Contribution

The study provides new experimental data on RADFET performance across a wide range of proton energies and doses.

## Key findings

- RADFET showed excellent linearity with a minimum R2 of 0.996 across proton energies.
- Sensitivity varied from 0.691 to 1.143 mV/Gy depending on proton energy.
- Stability was confirmed with low dispersion after high-dose irradiation.

## Abstract

The RADFET VT06 developed by Varadis (Cork, Ireland), which is aimed at high-dose applications, mainly for spacecraft missions, has been characterized by low- and high-energy proton beams at two different facilities, the Accelerator National Centre (Sevilla, Spain) and the Paul Scherrer Institute (PSI) located in Villigen (Switzerland), using a reader unit system developed by the University of Granada (Spain). The devices have been characterized with proton energies of 1, 2, 3, 150, and 230 MeV, with accumulated doses from 130 to 512 Gy, where the RADFET was unbiased during the irradiation while the source voltage was measured before and after irradiation to monitor the radiation dose. Excellent linearity has been obtained with a minimum correlation factor R2 of 0.996, with a sensitivity that can vary from (0.691 ± 0.007) mV/Gy for 1 MeV to (1.143 ± 0.023) mV/Gy for 230 MeV without any build-up layer. An excellent stability was found in the studied cases, with dispersion being lower than 4% after a dose accumulation higher than 500 and 200 Gy for protons of 1 and 3 MeV, respectively. The detectors demonstrated linear responses, very low sensitivity dispersion per set of samples, and excellent stability after irradiation. This shows that, with an appropriate readout system, the RADFET can become an excellent system for high-dose proton beams.