PRAGUE (Proton RAnGe measure Using silicon carbidE): the detector for proton range measurements in conventional and ultra-high dose rate beams

Accurate, fast, and dose-rate-independent measurements of Percentage Depth-Dose (PDD) distributions are essential for next-generation Quality Assurance and online range verification in proton therapy, particularly in view of Ultra-High Dose Rate (UHDR) beams for FLASH radiotherapy, where conventional water-scanning ionometric techniques are inadequate. The PRAGUE (Proton RAnGe measurement Using silicon carbidE) project addresses these challenges through the development of a multilayer detector based on Silicon Carbide (SiC) technology, capable of real-time reconstruction of the PDD distribution for proton beams in the 30-150 MeV energy range and under both conventional and UHDR conditions (107–1014 pps). By exploiting the radiation hardness, near-tissue equivalence, and fast charge-collection dynamics of 4H-SiC, the detector is designed to achieve high dosimetric accuracy (within 3%) with sub-millimetric longitudinal sampling (approximately 25–320 µm of water equivalent thickness per layer). This paper presents the conceptual framework and design of the PRAGUE system, including the electrical and functional characterisation of the SiC detectors, the development of a dedicated 64-channel readout chain based on the TERA08 ASIC, and the mechanical integration into a compact, irradiation-ready housing. The work provides evidence for the feasibility and robustness of the multilayer concept for accurate, real-time proton dosimetry, underlying its potential applications in high-intensity proton beams and future FLASH-radiotherapy workflows.