Speaker
Description
Detector characterization and instrumentation testing are routinely conducted at synchrotron and cyclotron facilities, many of which were originally designed for medical purposes. In experiments that rely on single-particle resolution—where pileup can severely impact data quality—detailed knowledge of the beam structure is essential for selecting appropriate readout parameters. However, this information is often not provided by the facility and can be difficult to obtain experimentally.
In this study, we present measurements of the spill structure at a medical accelerator facility using a high-frequency silicon carbide (SiC) based readout system. Owing to its high carrier saturation velocity and ability to withstand large bias voltages, SiC is particularly well suited for high-speed readout and precise timing measurements. Utilizing a novel 10 GHz readout setup and custom SiC diodes, we successfully characterized the beam structure on the sub-nanosecond scale, providing valuable insights into beam delivery to experimental setups. The arrival-time statistics exhibit a modulation at the accelerator’s RF frequency, arising from the characteristics of the machine’s extraction process—a factor not previously considered in pileup assessments.
The relevance of these measurements is demonstrated in the context of microdosimetric measurements, which demand single-particle spectroscopic precision at high dose rates and high amplitude resolution. Our results highlight the importance of knowing the beam-structure for the design of specialized readout electronics and reaffirm the suitability of SiC as a detector material for ultra-fast timing applications.