Characterizing the Delivered Spill Structure of Medical Proton and Carbon-Ion Beams at MedAustron using a High Frequency Silicon Carbide Readout

TL;DR

This paper introduces a high-speed silicon carbide sensor system to accurately characterize the spill structure of proton and carbon-ion beams at MedAustron, enabling detailed analysis of beam intensity at microsecond scales.

Contribution

The study presents a novel SiC-based detection setup capable of single-particle detection at sub-nanosecond resolution for medical synchrotron beams.

Findings

Successful characterization of spill structure beyond maximum ion revolution frequency.

Demonstrated capability of SiC sensors for high-flux beam monitoring.

Insights into beam intensity fluctuations at small time scales.

Abstract

Medical synchrotrons are often used for testing instrumentation in high-energy physics or non-clinical research in medical physics. In many applications of medical synchrotrons, such as microdosimetry and ion imaging, precise knowledge of the spill structure and instantaneous particle rate is crucial. Conventional ionization chambers, while omnipresent in clinical settings, suffer from limitations in charge resolution and integration time, making single-particle detection at high dose rates unfeasible. To address these limitations, we present a beam detection setup based on a silicon carbide (SiC) sensor and a monolithic microwave integrated circuit (MMIC), capable of detecting single particles with a full width at half maximum (FWHM) pulse duration of 500 ps. At the MedAustron ion therapy center, we characterized the spill structure of proton and carbon-ion beams delivered to the irradiation room beyond the timescale of the maximum ion revolution frequency in the synchrotron. The resulting data offer valuable insights into the beam intensity at small time scales and demonstrate the capabilities of SiC-based systems for high-flux beam monitoring.