Radiation‐Induced Luminescence of a Medium‐OH Pure Silica Core Multimode Optical Fiber in Steady State and Pulsed X‐Ray Irradiations: Potential and Limitations for Dosimetry

A pure silica-core (PSC) optical fiber (OF) with medium hydroxyl (M–OH) content, optimized for visible signal transmission in harsh radiation environments, is studied as a candidate for radiation-induced luminescence (RIL) based dosimetry. The objective of this article is twofold: i) to evaluate whether this fiber can serve as a transport fiber for radioluminescence measurements when coupled to scintillating doped fiber probes and ii) to investigate its potential for standalone RIL-based dosimetry, particularly for high dose rates and pulsed radiation applications. A dedicated experimental setup, developed to simulate X-ray pulses, enables time-resolved RIL measurements to investigate memory effects and the exploitability under high dose rates, close to the ones of FLASH radiotherapy treatments (>40 Gy/s). The M–OH PSC OF exhibits promising response for RIL-based dosimetry, with a linear sensitivity increase with fiber length and significantly lower parasitic effects compared to the reference Ce3+ ion doped fiber. Its use as transport fiber seems promising as well, thanks to its overall negligible RIL contribution supporting its use in high-performance dosimetry systems.