Combining Micro-pattern gaseous detectors with optical imaging sensors, have been proven an effective method for accurate characterization of radiation beams. In response to the growing demand for large-area, real-time gamma rays dose monitoring in radiotherapy, an optical readout Micromegas detector was manufactured with a transparent indium tin oxide glass anode. Its effective area is 25 cm x 25 cm. Preliminary assessment employing X-ray sources yielded a spatial resolution of 375 mu m (at 10% modulation transfer function). Subsequently, the prototype was tested under clinical radiotherapy gamma rays. The results show that the linearity response exceeds 99.9% (R-squared value) for different doses. For a system-configured 100 mm field of view, the measured field size was 99.70 mm, and the penumbra width was determined to be 4.01 mm. These results indicate the good potential of this method for quality assurance in radiotherapy gamma rays. Additionally, the optical readout Micromegas is expected to be expanded to monitor other types of high-flux beams, such as medical pencil proton rays and neutron beams inspections by adding some conversion layers.

In this study, we present a time projection chamber (TPC) system for low-background beta radiation measurements. The system consists of a TPC with a two-dimensional strip readout Micromegas and an anti-coincidence detector with readout pads for cosmic ray vetoing. The detector system uses an AGET-based waveform sampling system for data acquisition. The beta detection capability of the system was verified through an experimental test using 90Sr beta source. In addition, a dedicated simulation program based on Geant4 was developed to model the entire detection process, including the responses to both the beta source and background radiation. The simulation results were compared with the experimental data for both beta and background samples, and they were in good agreement. Simulation samples were used to optimize and train the classification models for beta and background discrimination. By applying the selected model into test data, the system achieved a background rate of 0.49 cpm/cm^2 while retaining more than 55 0.0012 cpm/cm^2 .

The integration of resistive materials has fundamentally advanced Micro-Pattern Gaseous Detector (MPGD) technology, enabling robust, high-gain operation essential for modern particle physics experiments. Diamond-Like Carbon (DLC) has emerged as a superior material for this purpose due to its uniquely tunable electrical, mechanical, and chemical properties. This article provides a comprehensive review of the development, fabrication, and application of DLC-based resistive coatings for MPGDs, with a focus on work conducted by the University of Science and Technology of China MPGD group. We detail the material fundamentals of DLC, systematically introduce magnetron sputtering as the core deposition methodology, and analyze the critical relationship between coating properties—such as resistivity, uniformity, adhesion, and stability—and final detector performance. A thorough examination of specific detector architectures (μ-RWELL, μRGroove, THGEMs, RWELL, Picosecond Micromegas) demonstrates the transformative impact of DLC. Finally, we summarized the outstanding technical challenges and present a perspective on future research directions aimed at scaling this technology for next-generation experiments.

Micro-pattern gaseous detectors (MPGDs) are widely utilized in physics experiments owing to their excellent spatial resolution and high-rate capabilities. Within the PandaX-III experiment, which aims to investigate neutrinoless double beta decay, Micromegas detectors serve as charge readout devices. High energy resolution is a critical requirement for the readout plane in this context, and gain uniformity significantly impacts the achievable resolution, primarily because of the extended tracks of the two emitted electrons. However, scaling up MPGDs to larger active areas exacerbates the challenge of maintaining gain uniformity, and effectively controlling the uniformity of the avalanche gap is a key factor in the detector manufacturing process via the thermal bonding method. This study demonstrates that optimizing the thermal bonding films specifically at the detector edges can effectively improve the gain uniformity, achieving a gain non-uniformity of <5% over the entire 192 & times; 192 mm(2) active area in a 1 bar Ar/isobutane (96.5/3.5) gas mixture. Additionally, the gain non-uniformity of approximately 12% was characterized at high pressure of up to 10 bar, revealing promising potential for high resolution measurements in the PandaX-III experiment and other high-pressure applications.

To meet the needs of high counting rate and high time resolution in future high energy physics experiments, a prototype of a gas photodetector with a Resistive Plate Chamber (RPC) structure was developed. We simulated the detector's performance using Garfield++ and utilized an ultraviolet laser to evaluate the single photoelectron performance of various mixed gases. The detector uses a low-resistivity (similar to 1.4 x 1010 52 cm) float glass so that its rate capability is significantly higher than that of ordinary float glass (1012-1014 52 cm). The laser test results show that in the MRPC gas mixture (R134a/iC4H10/SF6 (85/10/5)), the best single photoelectron time resolution is 20.3 +/- 1.0 ps at an induced signal charge of 6 x 106 Qe. Increasing the concentration of iC4H10 can effectively reduce the probability of photon feedback, without changing the time resolution and maximum gain. In addition to its application in high-precision time measurement scenarios (e.g. T0 and TOF), the detector can also quantitatively evaluate the single photoelectron performance of various gases and will be utilized for identifying eco-friendly RPC gases.

Micro-pattern gaseous detectors (MPGDs), when integrated with optical imaging sensors, have been proven to effectively and accurately capture radiation beam information. To address the challenges of monitoring the dose and profile of medical pencil proton beams (MPPB), which have a high density of greater than 109 Hz/cm2, an optical readout micro-mesh gaseous structure (ORM) was proposed. A Micromegas prototype was manufactured with a glass substrate coated with transparent indium tin oxide as the detector anode. Its effective area is 8 cm x 8 cm. The ORM was firstly characterized with an Iron-55 X-ray source (55Fe) and a silver target X-ray tube individually, good energy resolution of 14.5% (FWHM), high gain greater than 104, and spatial resolution of 400 mu m (10% MTF) were achieved. The prototype was then tested with the MPPB. The evaluation revealed linear dose responses exceeding 99% (R-squared value) for both single-point and nine-point beam spots at various beam energies and doses. The size and center position deviation of the nine-point spot measurement were within 0.35 mm and 1 mm, respectively, indicating the good potential of this method for MPPB spot quality assurance. Additionally, the ORM is expected to be expanded to monitor other types of high-flux beams, such as medical neutron and gamma beam inspections, by adding suitable conversion layers.

Gaseous photomultiplier tubes sensitive to visible light and based on micro-pattern gaseous detectors have been widely investigated due to their wide range of potential applications. This study presents a novel triple micromesh gaseous structure (TMM) specifically designed for this purpose, featuring ultralow ion backflow (IBF). Prototypes of the TMM were manufactured and characterized with both an X-ray source and an ultraviolet laser, and the results demonstrated an unprecedented IBF ratio of 3 x 10-5 at gas gains exceeding 1 x 105, indicating a promising capability of TMMs for visible light detection.

SU-8 photoresist, specifically designed for micromachining and microelectronic applications, finds promising applications in developing Micro Pattern Gas Detector (MPGD) structures, e.g. GridPix, due to its excellent adhesion and chemical resistance. In this study, SU-8 delayed development technology was explored, leading to the fabrication of the SU-8 Micromegas on a quartz substrate with an effective signal gain of ∼10 3 . Additionally, a micro-groove detector, featuring a simple pattern and stable mechanical structure that proved highly compatible with the SU-8 process, was developed on quartz and achieved a similar gain of ∼10 3 . Further research focused on the preliminary development of SU-8 micro-resistive groove (μRGroove) on PCB substrates, incorporating a diamond-like carbon (DLC) resistive layer. Challenges such as bonding strength and internal stress were successfully addressed, resulting in the fabrication of the first sample. Despite a relatively low gain of ∼100, this study showcases the initial mastery of using SU-8 to fabricate various detector structures on standard lithography substrates. Significant potential to directly prepare MPGD structures on chips for high-precision applications, such as X-ray polarization measurement, and targeted process development for PCB substrates and DLC resistive electrodes, is foreseen.

The electrode's resistivity is crucial for resistive gaseous detectors' rate capability. We developed a precise timing gaseous photodetector with a glass RPC structure (photo-RPC). The detector's rate capability and timing performance were measured with different resistive float glass. The results show that compared to the photo-RPC with a high-resistivity electrode, the detector with very low-resistivity (1.5 x 10(9) Omega cm) glass shows greatly improved rate capability, while the time resolution and gain remains unchanged.

The Picosec MicroMegas collaboration aims to develop gaseous fast-timing detectors; experimentally, intrinsic time resolutions from around 50 ps to better than 20 ps are obtained, depending on the exact detector configuration. Parts of developments focus on exploring various options of fast-timing multi-channel frontend electronics, to meet the data processing demands of experimental applications. One option is the FastIC, which was developed for reading out positive and negative input polarity sensors with intrinsic amplification. In this paper, the first results from reading out the gaseous Picosec MicroMegas detector with the FastIC are presented. In laboratory studies, a basic description of the data processing chain was performed using a function generator. The results from test beam measurements are used to characterise the timing performance and the charge processing of the combination of FastIC and Picosec MicroMegas, as well as to demonstrate the possibility of a multi-channel detector readout. Although the timing-at-threshold level of the FastIC introduces a time walk of around 1.5 ns, time resolutions of around 50 ps have been achieved.

High-precision time measurement electronics play a crucial role in many particle physics experiments. In this paper, the design and testing of RF-amplifier-based prototype electronics for the high-precision time measurement of fast signals are introduced. The effects of parameters such as bandwidth, noise performance, and gain on time precision are analyzed in this design. Based on the analysis, the pre-amplification circuit is optimized. Utilizing the optimized pre-amplification circuit and the Domino Ring Sampler (DRS4) chip with a sampling rate of 5.12 Gsps, the prototype electronics are developed. To evaluate the performance of the electronics, a series of tests were conducted using a high-speed pulse generator, achieving time precision better than 5 ps. Additionally, laser and beam tests were conducted using the electronics in combination with a fast-timing Micromegas detector. In the beam test, the time resolution of the overall system, including the electronics and detector, was better than 23 ps.

The Super τ -Charm Facility (STCF) is a high-luminosity electron-positron collider under development in China. STCF requires excellent particle identification for charged hadrons within its energy range, necessitating a ≥4σ separation for π /K identification at the momentum range of 2 GeV/c and below. To meet these stringent requirements, a Cherenkov detector, Ring Imaging Cherenkov counter(RICH), has been selected as the baseline candidate for STCF. Our research focuses on a cascaded micro-pattern gaseous detector based on THGEM and Micromegas, providing high gain, large area coverage, and high counting rate capability. Furthermore, we are exploring the feasibility of a novel photodetector based on a double micro-mesh gaseous structure.

The Micro-Resistive Groove (mu RGroove) mu RGroove) is a single-stage Micro-Pattern Gaseous Detector (MPGD) with a groove amplification pattern. The resistive protection electrode is Diamond-Like Carbon (DLC), ensuring the detector achieves gas gain (>= 10(4)) and maintains good stability. The top copper layer of the groove is strip-shaped and can be grounded for 1D-strip readout. Therefore, only an additional 1D-strip is required to achieve 2D spatial resolution. Because the 2D readout is divided on both sides of the amplification structure, the induced charge-sharing effect is avoided, effectively increasing the induced signal amplitude, which is beneficial for applications of large-area tracking and cylindrical MPGD. In this study, we present the design and performance of the 10 cm x 10 cm mu RGroove prototype, which can achieve an effective gain of 2 x 10(4), an energy resolution of approximately 25%, a maximum detection efficiency close to 98%, and 2D spatial resolution better than 80 mu m. It also introduces the 50 cm x 50 cm large-area mu RGroove, which shows preliminary results with a detection efficiency > 96% and 2D spatial resolution better than 100 mu m, meeting the normal requirements for large-area tracking detection. Finally, it discusses the progress of the low-mass cylindrical mu RGroove, with the first prototype having an effective area of 13.1 cm in diameter and 10 cm in length. Its energy resolution is similar to 26% measured by 55 Fe and further beam tests being planned. This design is expected to become a practical solution for the inner tracker of the STCF.

The high-pressure xenon time projection chamber (TPC) utilizing micro-pattern gaseous detector readout has emerged as a highly promising technical solution for the search of neutrino-less double beta decay events. This approach offers exceptional features, including high energy resolution, fine granularity, low background radioactivity, and scalability for large-scale experiments. In line with these advantages, the PandaX-III experiment aims to implement a 10 bar Xe-136 TPC, employing a readout plane comprising 52 194 x 194 mm(2) Micromegas detectors, within the China Jinping Underground Laboratory. To fulfill the stringent experimental requirements of PandaX-III, a low-background Micromegas detector with high energy resolution was proposed and developed using the thermal bonding method. The performance of the thermal bonding Micromegas prototypes was investigated using X-ray characterization under various gas mixtures with argon and isobutane from 1 bar to 10 bars. Remarkable results were presented at 1 bar gas pressure, where a maximum gas gain of similar to 8 x 10(4) and the best energy resolution (FWHM @5.9 keV) of 13.6% is obtained, and at 10 bar pressure, where maximum gas gain exceeding 10(4), the best energy resolution of 19%, and excellent stability over a test duration exceeding 150 h is achieved.

The Super Tau-Charm Facility (STCF) is a future electron-positron collider operating in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5 × 10 35 cm -2 s -1 . A high-performance detector is required for the STCF experiment to meet the STCF physics goals. A low-material cylindrical inner tracker based on the micro-resistive well detector (μRWELL) is proposed for the STCF experiment. In this paper, the design of the μRWELL inner tracker is presented. A good balance between material budget, structural strength, and detector performance is achieved in the design where the material budget of the μRWELL inner tracker is estimated to be 0.29% X/X 0 , a 40% reduction w.r.t. that of the cylindrical gas electron multiplier (CGEM) detector used at the KLOE experiment. The hit position of the detector is reconstructed using an algorithm combing the micro-time projection chamber (μ-TPC) method and the charge center-of-gravity method. The detector performance was studied in detail using simulation with Garfield and Geant4. With the optimum working gas of Ar: CO 2 = 85:15, this detector can obtain a spatial resolution better than 100 μm and 400 μm in 1 T magnetic field in rφ and beamline direction, respectively. The simulated momentum resolution and vertex resolution of the whole STCF tracking system including the μRWELL inner tracker and a large drift chamber can meet the requirements for the STCF detector, benefiting from the optimized inner tracker design.

A transition-radiation detector (TRD) is a powerful device for highly relativistic electron (γ ≳ 1,000) identification. Electron identification is crucial for tagging the outgoing scattered electrons in an electron-ion collider (EIC) detector. Employing a TRD at the electron forward region of an EIC detector can provide the necessary electron identification with high hadron rejection over a wide momentum range. Thick gas electron multiplier (THGEM) technology is suitable for radiation detection in modern high-energy experiments owing to its high-granularity structure, radiation hardness, high-rate capability and ease of large-area production. This study investigates a TRD prototype based on THGEM technology through soft X-ray and electron beam experiments. Geant4 simulation were extensively exploited to understand the operation of TRD prototype with different gas mixtures. Particularly, the performance of TRD prototype with an electron beam at the DESY, with argon-based gas rather than xenon-based gas, agreed well with the simulation analyses in all important aspects. Based on the consistency of the experimental and simulation results, a likelihood analysis on the simulated total energy deposit in the xenon-based working gas would suggest a pion rejection improvement with the optimization of detector design, readout electronics and identification algorithm.

Fast timing detectors play an important role in high energy physics, medical imaging and other fields. In view of wider applications and potential in the future, new detector technologies need to be investigated. A novel detection concept of fast timing based on the double micro-mesh gaseous structure with a reflective photocathode (FT-DMM) is introduced in light of its good time resolution and long-term operation. A sufficient number of photoelectrons (PEs) and a time resolution of better than 300 picoseconds (ps) for single photoelectron (SPE) are obtained by simulations, suggesting that an overall time resolution better than 100ps is feasible. The FT-DMM prototype was fabricated and tested using ultraviolet (UV) light. The gas gain can reach up to 106, while the measured time resolution of SPE is consistent with the simulated one. Furthermore, a time resolution of approximately 115ps was achieved at an average number of PEs of 5.9, and better time resolution can be expected as more PEs to be generated. These results confirm the good potential of FT-DMM as a fast timing detector for charged particle and UV light detection.

Characterization of diamond-like carbon (DLC) coatings at cryogenic temperatures (down to 77 K) is presented, covering the electrical resistivity range of practical interest to gaseous and liquid particle instrumentation: 10^-1-10^5 Mohm/sq. The good behaviour observed in terms of linearity, surface uniformity and stability with time and transported charge add to other well-known characteristics like low chemical reactivity and tolerance to radiation. The observed temperature dependence and stability of electrical properties with transported charge is consistent with a conductivity mechanism based on 2-dimensional variable-range electron hopping, as expected for the surface conductivity of thin films made from amorphous carbon. First results from a resistive-protected WELL detector ('RWELL') built with DLC and operated close to the liquid-vapor coexistence point of argon (87.5 K at 1 bar) are presented.

The PICOSEC Micromegas (MM) detector is a precise timing gaseous detector consisting of a Cherenkov radiator combined with a photocathode and a MM amplifying structure. A 100-channel PICOSEC MM prototype with 10 × 10 cm 2 active area equipped with a Cesium Iodide (CsI) photocathode demonstrated a time resolution below σ = 18 ps. The objective of this work is to improve the PICOSEC MM detector robustness aspects, i.e. integration of resistive MM and carbon-based photocathodes, while maintaining good time resolution. The PICOSEC MM prototypes have been tested in laboratory conditions and successfully characterised with 150 GeV/c muon beams at the CERN SPS H4 beam line. The excellent timing performance below σ = 20 ps for an individual pad obtained with the 10 × 10 cm 2 area resistive PICOSEC MM of 20 MΩ/□ showed no significant time resolution degradation as a result of adding a resistive layer. A single-pad prototype equipped with a 12 nm thick Boron Carbide (B 4 C) photocathode presented a time resolution below σ = 35 ps, opening up new possibilities for detectors with robust photocathodes. The results made the concept more suitable for the experiments in need of robust detectors with good time resolution.

Beam monitoring and evaluation are very important to boron neutron capture therapy (BNCT), and a variety of detectors have been developed for these applications. However, most of the detectors used in BNCT only have a small detection area, leading to the inconvenience of the full-scale 2-D measurement of the beam. Based on micromegas technology, we designed a neutron detector with large detection area and high counting rate. This detector has a detection area of 288 mm multiples 288 mm and can measure thermal, epithermal, and fast neutrons with different detector settings. The BNCT experiments demonstrated that this detector has a very good 2-D imaging performance for the thermal, epithermal, fast neutron and gamma components, a highest counting rate of 94 kHz/channel, and a good linearity response to the beam power. Additionally, the flux fraction of each component can be calculated based on the measurement results. The Am-Be neutron source experiment indicates that this detector has a spatial resolution of approximately 1.4 mm, meeting the requirements of applications in BNCT. It is evident that this micromegas-based neutron detector with a large area and high counting rate capability has great development prospects in BNCT beam monitoring and evaluation applications.