Editorial: Particle and radiation sensors developed at INFN-CSN5

these detectors offer superior sensitivity and timing capabilities, enabling applications ranging from beam commissioning and monitoring to dosimetry in ultra-high dose rate and spatially fractionated radiotherapy. This work highlights the strong synergy between detector physics, electronics development, and clinical requirements. Closely related, the outcomes of the CSN5 eXFlu project are presented in a detailed study of ultrathin LGAD sensors. By reducing the active sensor thickness down to 15 μm, exceptional timing resolutions are achieved while maintaining remarkable radiation hardness. The demonstrated performance positions thin LGADs as key candidates for future high-precision timing applications in both fundamental physics and applied environments characterized by extreme radiation levels. Medical applications are further addressed through a comprehensive review of silicon carbide (SiC) detectors for advanced dosimetry. Thanks to its wide bandgap, radiation tolerance, and favorable physical properties, SiC emerges as a robust alternative to conventional dosimetric materials. The article surveys detector architectures and experimental results for photon, proton, carbon-ion, and FLASH radiotherapy, highlighting the potential of SiC to meet the demanding requirements of modern treatment techniques. Advanced silicon sensor technologies for future collider experiments are the focus of another contribution dedicated to 4D tracking. The paper reviews recent progress in sensor concepts capable of delivering excellent spatial and temporal resolution under unprecedented radiation levels. In particular, 3D silicon sensors are shown to satisfy key performance criteria, emphasizing the importance of sensor-electronics co-design and advanced fabrication techniques. Beyond traditional semiconductor detectors, the Research Topic also reflects CSN5's interest in novel materials and unconventional approaches. A mini-review is devoted to polysiloxane-based scintillators, highlighting their radiation hardness, mechanical flexibility, chemical versatility, and emerging applications ranging from neutron detection to real-time dose monitoring in proton therapy. Recent advances in photocurable and 3D-printable formulations further expand the design space of polymer-based radiation sensors. Another contribution presents the achievements of the ARCADIA collaboration in the development of fully-depleted CMOS monolithic sensors. By combining fast charge collection, low power consumption, and embedded electronics, these devices address the needs of high-rate particle and photon detection, spanning applications from time-of-flight measurements to X-ray imaging. The Research Topic also extends into the domain of quantum technologies. One article discusses integrated optics for the generation of squeezed vacuum states in lithium-niobate waveguides. These compact and robust sources have the potential to enhance precision measurements, including gravitational-wave detection, and represent a promising platform for future quantum sensing applications. Imaging performance is pushed further by the ASIX analog spectral imager for X-rays, introduced as a technology demonstrator targeting simultaneous high spatial and energy resolution. By adopting an ultra-low-noise, fully analog, asynchronous readout architecture, ASIX addresses charge-sharing limitations inherent to small-pixel devices and targets demanding applications in synchrotron science, material studies, and soft X-ray astrophysics. Radiation effects at the biological scale are addressed through contributions on microdosimetry. One review focuses on miniaturized tissue-equivalent proportional counters developed at INFN National Laboratories of Legnaro (LNL), optimized for stable operation in hadron therapy environments. These detectors provide microdosimetric quantities essential for linking physical dose to biological effectiveness. Finally, the activities of INFN within the Medipix4 international collaboration are summarized, highlighting the characterization of advanced hybrid pixel detectors based on Timepix4 and Medipix4 ASICs. These efforts contribute to the development of next-generation pixelated detectors featuring enhanced spatial, temporal, and energy resolution across a broad range of applications. Together, the contributions collected in this Research Topic reflect the diversity, coherence, and maturity of CSN5 activities. They emphasize the role of particle and radiation sensors as key enabling technologies at the interface between fundamental research and real-world applications, fully aligned with the interdisciplinary mission of Frontiers in Sensors.