Dual Cherenkov and Scintillation Response to High-Energy Electrons of Rare-Earth-Doped Silica Fibers

The investigation of the characteristic luminescent response of Ce-doped silica fibers exposed to electrons in the 20-200-GeV energy range is reported in this work to explore the feasibility of using silica-based fibers for a simultaneous dual-readout approach. The sol-gel method allows the preparation of either doped or undoped fibers with high aspect ratio and high purity, providing good flexibility and spatial resolution for the realization of a dual-readout detector. The dual Cherenkov and scintillation light emitted by silica-based fibers potentially offers applications in high-energy-physics calorimetry as well as in other fields, such as radiation monitoring in medicine, security, and industrial control. The response of the fibers, embedded in a tungsten-copper absorber block to obtain a spaghetti-like geometry in a high-energy-physics environment, is investigated through a test-beam campaign at the CERN Super Proton Synchrotron facility. The discrimination of Cherenkov and scintillation light is demonstrated and discussed, along with a detailed investigation of the scintillation properties of the material: time-resolved spectroscopy, relative light output, and attenuation length are evaluated. The results presented in this study can pave the way for further material engineering and future applications.