A single radiation hard pixel detector for proton dosimetry, imaging, energy resolution and beam monitoring
Abstract
Proton therapy enables highly conformal tumour irradiation by exploiting the Bragg peak. Clinical precision relies on detector systems that provide linearity, spatial resolution, radiation hardness, and, for ultra-high-dose-rate (FLASH) therapy, high dynamic range with sufficient temporal response. No compact all-in-one solution currently fulfils all these requirements. Here, we present pixelated gallium nitride (GaN) arrays as a multifunctional platform. These detectors exhibit high linearity (proton currents from 70 to 1700 pA cm-2) and signal uniformity below 2% across 128 pixels. To probe GaN radiation hardness, we applied cumulative doses up to 6.7 MGy at energies from 25 MeV down to the Bragg-peak regime. Locally deposited dose dictates long-term signal loss, yet devices preserve linearity and spatial response. We demonstrate 0.25 mm effective spatial resolution, validated against radiochromic film. Proton radiography resolves fine tissue structures, with the dose extrapolated to 7 mGy per 1 ms frame in a prospective single-shot configuration. Energy-dependent responses match GATE/Geant4 simulations, and wedge measurements enable Bragg-peak tracking with an energy resolution below 10 keV in an optimised geometry. Real-time ms-scale beam monitoring enables live dose verification.These results establish GaN pixel detectors as a scalable and radiation-hard platform, enabling dosimetry, beam monitoring and energy verification in one device.
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BibTeX
@misc{brosda2026single,
title = {{A single radiation hard pixel detector for proton dosimetry, imaging, energy resolution and beam monitoring}},
author = {Nico Frederic Brosda and Stephane Higueret and Nicolas Arbor and Matilde Siviero and Maxime Hugues and Eric Frayssinet and Luisa Parschat and Christian Baumer and Andreas Dirk Wieck and Jean Yves Duboz},
howpublished = {HAL},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.20304},
eprint = {2610.20304},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05842434v1},
}
RIS
TY - UNPB
TI - A single radiation hard pixel detector for proton dosimetry, imaging, energy resolution and beam monitoring
AU - Nico Frederic Brosda
AU - Stephane Higueret
AU - Nicolas Arbor
AU - Matilde Siviero
AU - Maxime Hugues
AU - Eric Frayssinet
AU - Luisa Parschat
AU - Christian Baumer
AU - Andreas Dirk Wieck
AU - Jean Yves Duboz
PY - 2026
DA - 2026/10/14
PB - HAL
DO - 10.48550/arxiv.2610.20304
UR - https://hal.science/hal-05842434v1
AB - Proton therapy enables highly conformal tumour irradiation by exploiting the Bragg peak. Clinical precision relies on detector systems that provide linearity, spatial resolution, radiation hardness, and, for ultra-high-dose-rate (FLASH) therapy, high dynamic range with sufficient temporal response. No compact all-in-one solution currently fulfils all these requirements. Here, we present pixelated gallium nitride (GaN) arrays as a multifunctional platform. These detectors exhibit high linearity (proton currents from 70 to 1700 pA cm-2) and signal uniformity below 2% across 128 pixels. To probe GaN radiation hardness, we applied cumulative doses up to 6.7 MGy at energies from 25 MeV down to the Bragg-peak regime. Locally deposited dose dictates long-term signal loss, yet devices preserve linearity and spatial response. We demonstrate 0.25 mm effective spatial resolution, validated against radiochromic film. Proton radiography resolves fine tissue structures, with the dose extrapolated to 7 mGy per 1 ms frame in a prospective single-shot configuration. Energy-dependent responses match GATE/Geant4 simulations, and wedge measurements enable Bragg-peak tracking with an energy resolution below 10 keV in an optimised geometry. Real-time ms-scale beam monitoring enables live dose verification.These results establish GaN pixel detectors as a scalable and radiation-hard platform, enabling dosimetry, beam monitoring and energy verification in one device.
ER -