The DLC-RPC is a resistive plate chamber employing diamond-like carbon electrodes. This detector has an ultra-low material budget due to its thin-film construction and has demonstrated a high-rate tolerance of up to 1 MHz/cm 2. In this study, we extend previous investigations by evaluating the discharge-quenching capability and long-term stability of DLC-RPCs with strip-shaped current-evacuation patterns using additional electrode configurations and hit rates of up to O 10 k H z / m m 2. The results provide empirical design guidelines for the protection of the current-evacuation pattern and identify operational limitations relevant to stable long-term operation under high-rate irradiation. These findings constitute an intermediate step toward the development of a DLC-RPC-based beam-monitoring detector.
F. D. Leite, J. M. Reis, J. F. C. A. Veloso, S. Pessanha, A. L. M. Silva
Gaseous detectors offer an attractive alternative to commonly used semiconductor detectors in X-ray Fluorescence Computed Tomography (XFCT) systems, mainly due to their potential for large active areas and lower cost. In this work, a novel concept of XFCT imaging was investigated through Monte Carlo simulations using the GATE software. The simulated system integrates a collimation-based optical system and a position and energy-sensitive gaseous detector, filled with krypton gas, for fluorescence photon detection. Three phantoms with different geometries, sizes, elemental compositions, and attenuation conditions were simulated to evaluate the system’s capability. The results demonstrate the ability of the system to discriminate multiple elements and to reconstruct cross-sectional and three-dimensional elemental images, confirming the feasibility of XFCT imaging based on gaseous detectors. These findings highlight the potential of this approach as an alternative to semiconductor-based XFCT systems, supporting further optimization and experimental validation.
Alberto Blanco, Paulo Fonte, Luis Lopes, Mario Pimenta
Resistive Plate Chambers (RPCs) are gaseous detectors widely used in High Energy Physics due to their excellent timing performance, high efficiency, scalability, and affordability. However, their operation relies on gas mixtures based on hydrofluorocarbons (HFCs), whose high Global Warming Potential and progressive phase-out under current environmental regulations pose significant challenges for the long-term sustainability of RPC technology. In this work, we investigate a conceptually different approach, as an alternative to eco gas-mixture substitution strategies, based on sealed RPCs, in which the detector is filled with standard gas during assembly and subsequently hermetically sealed, allowing operation without any external gas supply. This approach drastically reduces gas consumption, eliminates the need for complex gas systems, and offers a potential solution compatible with both environmental constraints and high-performance operation. Two sealed RPC configurations, with active areas of approximately 0.1 m 2 and 1 m 2, have been developed and characterized using atmospheric cosmic muons. The 0.1 m 2 module demonstrates stable operation over an extended period of nearly two continuous years, with an average efficiency of about 98% and low streamer probability. The 1 m 2 prototype exhibits a comparable initial response, although limitations related to mechanical stability are observed. These results demonstrate the feasibility of sealed RPC technology for trigger applications and highlight its potential as a robust, cost-effective, and environmentally sustainable alternative for future gaseous detector systems.
Phasit Petisiwaveth, Amy Dickinson, Lorenzo Margotti, Andrea Ciavatti, Beatrice Fraboni, Paul Sellin, Marco Petasecca
Perovskite materials have recently emerged as promising candidates for radiation detection due to their strong X-ray absorption, efficient charge transport, and tunable optical properties. However, their performance in scintillation-based dosimetry remains insufficiently explored. This study systematically evaluates the radiation attenuation, radioluminescence, and dosimetric characteristics of two-dimensional organic–inorganic perovskite scintillators, B A 2 P b B r 4 and P E A 2 P b B r 4, in comparison with conventional plastic (E J 212) and inorganic (B G O, L Y S O) scintillators under low-energy X-ray irradiation. The perovskite samples exhibited mass attenuation coefficients significantly higher than those of the plastic scintillator and comparable to dense inorganic crystals, reflecting their high- Z composition. Under X-ray excitation, both materials exhibited narrow radioluminescence emission bands centred near 420 n m. The measured light yields were approximately 9.8 × 1 0 3 and 4.8 × 1 0 3, p h o t o n s M e V − 1 for B A 2 P b B r 4 and P E A 2 P b B r 4, respectively, indicating efficient conversion of absorbed X-ray energy into visible emission. Dosimetric measurements showed excellent dose linearity (R 2 > 0.999), high sensitivity despite small thicknesses, and stable, repeatable responses with relative standard deviations below 1.3 %. The perovskites also maintained consistent dose-rate behaviour across 0.11– 1.12 m G y s − 1. Energy-dependent measurements revealed enhanced responses at lower photon energies, consistent with photoelectric absorption. Notably, differences between B A 2 P b B r 4 and P E A 2 P b B r 4 highlight the ability to tailor energy response through modifications of the organic spacer or inorganic framework, enabling compositionally engineered scintillators optimized for specific dosimetric tasks. Overall, these results show that organic–inorganic perovskite scintillators bridge the performance gap between plastic and inorganic materials, offering high sensitivity, stability, and compositional tunability, positioning them as versatile candidates for next-generation diagnostic X-ray detection and real-time dosimetry.
Multi-gap resistive plate chamber (MRPC) technology has become one of the most important detector solutions for time-of-flight (TOF) systems because of their good time resolution, high efficiency, suitability for constructing large-area TOF walls by tiling many modules, and relatively low cost. However, with the increase in accelerator luminosity and event rate, traditional float-glass MRPCs face challenges under high particle flux, including rate-induced voltage drop on resistive plate electrodes, gas contamination and aging, and local instability around spacer regions. These effects directly limit the rate capability, long-term stability, and time resolution of MRPC detectors in TOF system. We summarize recent progress in high rate MRPC technology on three main optimization directions. The first is resistive plate electrode optimization using low resistive glass. This reduces the average voltage drop under irradiation, allowing the detector to maintain an efficiency above 90 % and a time resolution better than 80 p s at particle fluxes up to 60 k H z / c m 2. The second is gas flow and exchange optimization using sealed MRPC structures. This design reduces the internal gas volume by a factor of about 50 and enables stable operation at a low gas flow rate of 1 m l / m i n, effectively mitigating gas-related aging effects. The third is spacer-related optimization using improved spacer designs like pad spacers and thermal-bonding spacers. These designs decrease the local electric-field distortion by more than a factor of three and reduce the noise rate by two orders of magnitude, significantly improving long-term stability. Experimental results from beam tests and X-ray tests show that these optimization directions are effective and complementary. These developments provide a practical technological route for MRPC detectors operating in high particle flux experiments such as CBM-TOF.
