Speaker
Description
The MATRIX project explores advancements in proton therapy by developing durable detectors for improved real-time beam and dose monitoring. Proton irradiation enables precise tumor targeting while minimizing damage to healthy tissue. Current detection methods, including ionization chambers, scintillators, and silicon-based detectors, face limitations, particularly the degradation of silicon under prolonged exposure to high-energy protons (65–230 MeV) or lack of linearity and even saturation for scintillators.
To address this, MATRIX investigates the use of gallium nitride (GaN) semiconductor, which offers higher radiation resistance than silicon. Proton detection is achieved by measuring the current induced in pin GaN diodes. GaN, widely used in LED technology, is cost-effective, can be grown on large-size wafers (up to 300 mm), and enables the development of long-lasting detector arrays. Combined with silicon-based electronics placed outside the irradiation field, this approach shall enhance system stability and performance.
MATRIX has developed a GaN-based detector prototype, including linear diode arrays with 128 elements and two-dimensional arrays up to 11×11, covering 1 cm² with up to 500 µm spatial resolution. Smaller diode sizes and thus higher resolutions are obtainable thanks to the utilized microelectronic processes.
To evaluate the performance of these GaN-based detectors and understand the detector’s response to primary and secondary particles, Monte Carlo simulations were conducted using the Gate 10.0 platform to model the proton beam line. The simulation results were compared with experimental data from proton irradiation experiments performed at the Cyrcé platform of the Institut Pluridisciplinaire Hubert Curien in Strasbourg, using proton beams with energies around 20 MeV and proton currents around 2 nA.
Comparing experimental data and Monte Carlo calculations, we will present the performances of the MATRIX GaN detector under different irradiation conditions, e.g., with higher proton energies of different facilities. This comparison also allows us to assess the simulations' accuracy and validate the experimental setup. Based on high-dose measurements, we will discuss radiation tolerance. The results give insight into potential applications of the MATRIX detector in beam and dose monitoring for proton therapy systems.
| Workshop topics | Sensor materials, device processing & technologies |
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