The PICOSEC Micromegas detector is a Micro-Pattern Gaseous Detector (MPGD) concept developed to achieve tens of picosecond-level timing resolution for charged particle detection by combining a Cherenkov radiator with a two-stage Micromegas amplification structure. To improve operational robustness at high gain and under intense radiation backgrounds, a resistive anode has been implemented using a diamond-like carbon (DLC) layer deposited on a Kapton substrate. While this design enhances detector stability, the resistive layer may influence rate capability, signal formation, and detector capacitance, altering its timing performance.x In this work, a comprehensive study of a resistive PICOSEC design is presented, including an analytical model and finite-element simulation to quantify rate-dependent gain reduction due to ohmic voltage drop in the resistive layer. An analytical solution for the voltage distribution across a finite-size resistive layer is derived, and a numerical model is developed to evaluate gain suppression under intense particle fluxes. For the single-channel prototype geometry and expected beam conditions at the CERN SPS H4 beam line, surface resistivities around 20 M Omega/square are found to ensure discharge protection and acceptable gain stability. The impact of the resistive layer on signal integrity is investigated using an extended Ramo-Shockley formalism with time-dependent weighting fields and Garfield++ simulations. The contribution of delayed signal components induced by the resistive layer is quantified, and a preservation of the leading-edge of the signal was found for surface resistivities exceeding 100 k Omega/square. Single-channel resistive-anode prototypes were designed (& empty;10 and & empty;15 mm), constructed, and experimentally characterized. Laboratory measurements using single photoelectrons and a power spectral density analysis show the predicted reduction in signal amplitude due to the insulating layer, while preserving the leading edge of the electron peak. Muon beam tests with both CsI and DLC photocathodes were performed. They demonstrate a time resolution of 11.5 +/- 0.4 ps using CsI, comparable to the 11.9 +/- 0.4 ps of the metallic-anode device, showing the suitability of the resistive design for precision timing applications in challenging operational conditions.

The PICOSEC Micromegas detector is a precise-timing gaseous detector based on a Cherenkov radiator coupled with a semi-transparent photocathode and a Micromegas amplifying structure, targeting a time resolution of tens of picoseconds for minimum ionising particles. Initial single-pad prototypes have demonstrated a time resolution below a = 25 ps, prompting ongoing developments to adapt the concept for High Energy Physics applications, where sub-nanosecond precision is essential for event separation, improved track reconstruction and particle identification. The achieved performance is being transferred to robust multi-channel detector modules suitable for large-area detection systems requiring excellent timing precision. To enhance the robustness and stability of the PICOSEC Micromegas detector, research on robust carbon-based photocathodes, including Diamond-Like Carbon (DLC) and Boron Carbide (B4C), is pursued. Results from prototypes equipped with DLC and B4C photocathodes exhibited a time resolution of a approximate to 32 ps and a approximate to 34.5 ps, respectively. Efforts dedicated to improve detector robustness and stability enhance the feasibility of the PICOSEC Micromegas concept for large experiments, ensuring sustained performance while maintaining excellent timing precision.

This paper presents design guidelines and the experimental verification of a single-channel PICOSEC Micromegas (MM) detector with an improved time resolution. The design encompasses the detector board, vessel, auxiliary mechanical parts, and electrical connectivity for high voltage (HV) and signals, focusing on improving the stability, reducing noise, and ensuring signal integrity to optimize timing performance. A notable feature is the simple and fast reassembly procedure, facilitating quick replacement of the detector internal components that allows for an efficient measurement strategy involving different detector components. The paper also examines the influence of parasitic capacitance and inductance on the output signal integrity. To validate the design, a prototype assembly and three interchangeable detector boards with varying readout pad diameters were manufactured. Detectors were initially tested in the laboratory. Finally, the timing performance of the detectors with different pad sizes was verified using 150 GeV muons. Notably, a record time resolution for a PICOSEC Micromegas detector technology with a CsI photocathode of 12.5 +/- 0.8 ps was achieved for a detector with 10 mm diameter readout pad size.

PICOSEC Micromegas (MM) is a precise timing gaseous detector based on a Cherenkov radiator coupled with a semi-transparent photocathode and an MM amplifying structure. The detector concept was successfully demonstrated through a single-channel prototype, achieving sub-25 ps time resolution with Minimum Ionizing Particles (MIPs). A series of studies followed, aimed at developing robust, large-area, and scalable detectors with high time resolution, complemented by specialized fast-response readout electronics. This work presents recent advancements towards large-area resistive PICOSEC MM, including 10 × 10 cm 2 area prototypes and a 20 × 20 cm 2 prototype, which features the jointing of four photocathodes. The time resolution of these detector prototypes was tested during the test beam, achieved a timing performance of around 25 ps for individual pads in MIPs. Meanwhile, customized electronics have been developed dedicated to the high-precision time measurement of the large-area PICOSEC MM. The performance of the entire system was evaluated during the test beam, demonstrating its capability for large-area integration. These advancements highlight the potential of PICOSEC MM to meet the stringent requirements of future particle physics experiments.

The PICOSEC-Micromegas (PICOSEC-MM) detector is a novel gaseous detector designed for precise timing resolution in experimental measurements. It eliminates time jitter from charged particles in ionization gaps by using extreme UV Cherenkov light emitted in a crystal, detected by a Micromegas photodetector with an appropriate photocathode. The first single-channel prototype tested in 150 GeV/c muon beams achieved a timing resolution below 25 ps, a significant improvement compared to standard Micropattern Gaseous Detectors (MPGDs). This work explores the specifications for applying these detectors in monitored neutrino beams for the ENUBET Project. Key aspects include exploring resistive technologies, resilient photocathodes, and scalable electronics. New 7-pad resistive detectors are designed to handle the particle flux. In this paper, two potential scenarios are briefly considered: tagging electromagnetic showers with a timing resolution below 30 ps in an electromagnetic calorimeter as well as individual particles (mainly muons) with about 20 ps respectively.

The PICOSEC Micromegas (MM) detector is a precise timing gaseous detector based on a MM detector operating in a two-stage amplification mode and a Cherenkov radiator. Prototypes equipped with cesium iodide (CsI) photocathodes have shown promising time resolutions as precise as 24 picoseconds (ps) for Minimum Ionizing Particles. However, due to the high hygroscopicity and susceptibility to ion bombardment of the CsI photocathodes, alternative photocathode materials are needed to improve the robustness of PICOSEC MM. Diamond-like Carbon (DLC) film have been introduced as a novel robust photocathode material, which have shown promising results. A batch of DLC photocathodes with different thicknesses were produced and evaluated using ultraviolet light. The quantum efficiency measurements indicate that the optimized thickness of the DLC photocathode is approximately 3 nm. Furthermore, DLC photocathodes show good resistance to ion bombardment in aging test compared to the CsI photocathode. Finally, a PICOSEC MM prototype equipped with DLC photocathodes was tested in muon beams. A time resolution of around 42 ps with a detection efficiency of 97% for 150 GeV/c muons were obtained. These results indicate the great potential of DLC as a photocathode for the PICOSEC MM detector.

Future high-luminosity experiments require timing precision of the order of tens of picoseconds for pileup mitigation while aiming at instrumenting large active areas. PICOSEC Micromegas detectors combine a Cherenkov radiator with a photocathode and a two-stage gaseous amplification structure to achieve timing precision of $\lt25 \mathrm{ps}$ for minimum ionising particles [1] while allowing for economic area coverage. We present the development of tileable detector modules achieving high timing precision and optimisations in detector construction and signal routing which improve the achievable resolution to better than 20 ps. In parallel, new developments towards maintaining performance in challenging environments are pursued including alternative photoconversion layers which tolerate higher levels of ion back flow and resistive amplification structures. Carbon-based photocathodes including diamond-like carbon and $B_{4} C$ are evaluated and timing resolution values in the range of $30-40$ ps were obtained. Resistive detector technologies including resistive Micromegas and $\mu$ RWELL detectors were implemented to withstand high-rate environments. To profit from efficient protection against discharges and minimise the influence of delayed signal components on timing performance, high resistivity electrodes are used and comparable time resolution to non-resistive prototypes is demonstrated. The performance of different scalable readout approaches is compared to demonstrate the availability of suitable electronic readout schemes for multi-module detector systems. Dedicated preamplifiers coupled with waveform-digitising TDCs are used for constantfraction discrimination while a threshold-based timing ASIC is shown to allow for timewalk correction with complementary energy information. The presented developments illustrate the versatility of PICOSEC Micromegas precise timing detectors and their compatibility with challenging environments for high-pileup environments as well as photo detection.

Positron emission tomography (PET) is a radionuclide functional diagnostic imaging technique for medical applications such as cancer diagnosis and drug development. Jefferson Lab is developing PET instrumentation using a novel data acquisition system (DAQ) readout methodology referred to as streaming readout (SRO). The SRO-based approach transitions PET DAQ systems from traditional dedicated "triggered" systems to more versatile "triggerless" systems. In this new configuration, the SRO-enabled PET detector modules are interconnected using Ethernet with synchronized external timing circuitry. The SRO-PET system implementation is entirely software-based, encompassing detector calibrations and coincident event sorting. The adoption of SRO technology in PET instrumentation has the potential to simplify system installation and enhance key performance indices, especially for whole-body and total-body PET applications.

INTRODUCTION:Sentinel lymph node biopsy (SLNB) is a standard practice for staging cutaneous melanoma. High false-negative rates have an increased interest in adjunctive techniques for localizing SLNs. Mobile gamma cameras (MGCs) represent potential tools to enhance SLNB performance. METHODS:An institutional review board approval was obtained for this study (ClinicalTrials.gov ID NCT01531608). After obtaining informed consent, 20 eligible melanoma patients underwent 99mTc sulfur colloid injection and standard lymphoscintigraphy with a fixed gamma camera (FGC). A survey using a 20 cm square MGC, performed immediately preoperatively by the study surgeon, was used to establish an operative plan while blinded to the FGC results. Subsequently, SLNB was performed using a gamma probe and a novel 6 cm diameter handheld MGC. RESULTS:A total of 24 SLN basins were detected by FGC. Prior to unblinding, all 24 basins were identified with the preoperative MGC and the operative plan established by preoperative MGC imaging was confirmed accurate by review of the FGC images. All individual sentinel lymph nodes were identified during intraoperative MGC imaging, and in 5/24 (21%) cases, surgeon-reported additional clinically useful information was obtained from the MGC. CONCLUSIONS:Preoperative MGC images provide information consistent with FGC images for planning SLNB and in some cases provide additional information that aided in surgical decision-making.

We present the development of a new concept of fast timing gaseous detector, the µRWELLPICOSEC detector based on Resistive Micro-Well (µRWELL) technology to provide timing resolution in the tens of picosecond range for application as time-of-flight (TOF) technology in the particle physics and medical instrumentation fields. The µRWELL-PICOSEC technology combined a Cerenkov radiator for the generation of Cerenkov photons from high energy charged particles, a photocathode for the conversion of the produced photons into primary electrons and the µRWELL foil for the multiplication of the electron to produce large signal on pad segmentation readout. The proof of concept of µRWELL-PICOSEC is demonstrated with a small single-channel prototype and preliminary timing performance of 90 ps has been measured. Optimization study the amplification structure of µRWELL-PICOSEC for the improvement of timing resolution is discussed and results on timing performance studies in beam at CERN are presented. The development of large area (100 mm × 100 mm) µRWELL-PICOSEC and associated multichannel fast readout electronics and data acquisition system are also reported.

A radiation detector system is under development that uses time of flight (TOF) information within two optical fiber complexes that are optically coupled to scintillators at repeated intersections. Silicon Photomultipliers (SiPM) are placed at the ends of each fiber complex to detect scintillation events. The fiber complex is built with combination of wavelength-shifting fibers and clear Poly(methyl methacrylate) (PMMA) optical fibers. An oscilloscope is used for processing the two signals and to measure TOF differences to estimate the location of scintillation events. For the initial test, two scintillation beads were built and used detect beta particles. The system is scalable, capable of being adaptively shaped or curved, and customizable in terms of spatial resolution and sensitivity with the same number of SiPMs. The feasibility of the concept is supported by our previous studies. The system is anticipated to be suitable for over several meters for coarse radiation detection such as in the application of monitoring of radioactive material storage areas.

Advanced detector R&D requires performing computationally intensive and detailed simulations as part of the detector-design optimization process. We propose a general approach to this process based on Bayesian optimization and machine learning that encodes detector requirements. As a case study, we focus on the design of the dual-radiator Ring Imaging Cherenkov (dRICH) detector under development as a potential component of the particle-identification system at the future Electron-Ion Collider (EIC). The EIC is a US-led frontier accelerator project for nuclear physics, which has been proposed to further explore the structure and interactions of nuclear matter at the scale of sea quarks and gluons. We show that the detector design obtained with our automated and highly parallelized framework outperforms the baseline dRICH design within the assumptions of the current model. Our approach can be applied to any detector R&D, provided that realistic simulations are available.

In its latest Long Range Plan for Nuclear Science Research in the U.S., the Nuclear Science Advisory Committee to the Department of Energy recommended that in regards to new nuclear-physics facilities, the construction of an Electron Ion Collider (EIC) be of the highest priority after the completion of the Facility for Rare Isotope Beams. In order to carry out key aspects of the scientific program of the EIC, the EIC central detector must be capable of hadron particle identification (PID) over a broad momentum range of up to 50 GeV/c. The goal of the EIC-PID consortium is to develop an integrated program for PID at EIC, which employs several different technologies for imaging Cherenkov detectors. Here we discuss the conceptual designs and the expected PID performance of two of these detectors, as well as the newest results of gain evaluation studies of photon sensors that are good candidates to read out these detectors. Development of a gas-aerogel dual-radiator Ring Imaging Cherenkov (dRICH) detector with outward focusing mirrors is being pursued for the hadron endcap. Simulations demonstrate that the dRICH can provide a continuous ⩾ 3σ π /K/p separation from 2.5 GeV/c to 50 GeV/c. A modular aerogel Ring Imaging Cherenkov (mRICH) detector with a Fresnel lens as a focusing element is being pursued for the electron endcap. The design provides for hadron identification over a momentum range of 3 GeV/c–10 GeV/c. The working principle of the mRICH design has been proven in a beam test with a first prototype. The location of the sensor readout planes of the Cherenkov detectors in the magnetic field of the central-detector solenoid, which is expected to be within 1.5 T–3 T, makes is necessary to evaluate the limit of the acceptable performance of commercially available photosensors, such as microchannel-plate photomultipliers (MCP PMTs). Here we present the results of gain evaluation of multi-anode MCP PMTs with a pore size of 10 μm. Overall, our preliminary results suggest that the 10-μm pore-size sensors can be operated in a magnetic field with magnitude up to Bmax of 2 T. The value of Bmax depends on the relative orientation between the sensor and the field.

An Electron-Ion Collider (EIC) has been proposed to further explore the strong force and QCD, focusing on the structure and the interaction of gluon-dominated matter. A generic detector R&D program (EIC PID consortium) for the particle identification in EIC experiments was formed to explore technologically advanced solutions in this scope. In this context two Ring Imaging Cherenkov (RICH) counters have been proposed: a modular RICH detector which consists of an aerogel radiator, a Fresnel lens, a mirrored box, and pixelated photon sensor; a dual-radiator RICH, consisting of an aerogel radiator and C2F6 gas in a mirror-focused configuration. We present the simulations of the two detectors and their estimated performance.

A powerful new electron-ion collider (EIC) has been recommended in the 2015 Long Range Plan for Nuclear Science for probing the partonic structure inside nucleons and nuclei with unprecedented precision and versatility [1]. EIC detectors are currently under development [2], all of which require hadron identification over a broad kinematic range. A prototype ring imaging Cherenkov detector has been developed for hadron identification in the momentum range from 3 GeV/c to 10 GeV/c. The key feature of this new detector is a compact and modular design, achieved by using aerogel as radiator and a Fresnel lens for ring focusing. In this paper, the results from a beam test of a prototype device at Fermilab are reported. Published by Elsevier B.V.

Excellent particle identification (PID) is an essential requirement for a future Electron-Ion Collider (EIC) detector. Identification of the hadrons in the final state is critical to study how different quark flavors contribute to nucleon properties. Reliable identification of the scattered electron is important for covering kinematics where pion backgrounds are large. The EIC PID consortium (eRD14) was formed to develop an integrated PID program using a suite of complementary technologies covering different ranges in rapidity and momentum, as required by the asymmetric nature of the collisions at the EIC. The PID consortium has also worked closely with BNL and JLab to ensure that the specific R&D projects are compatible with the detector concepts that are being pursued there.