We present the first results from tests of a MICROMEGAS detector manufactured using the so-called "bulk" technology and having a resistive cathode mesh instead of the conventional metallic one. This detector operates as usual MICROMEGAS, but in the case of sparks, which may appear at high gas gains, the resistive mesh reduces their current and makes the sparks harmless. This approach could be complementary to the ongoing efforts of various groups to develop spark-protected MICROMEGAS with resistive anode planes.
We have developped a model to simulate the behavior of a resistive micromegas (MICROMEsh GAseous Structure) detector to a discharge using an electronic software (Virtuoso).
A novel read-out architecture has been developed for the Micromegas detector. The anode element is made of a resistive layer on a ceramic substrate. The detector part is entirely separated from the read-out element. Without significant loss, signals are transmitted by capacitive coupling to the read-out pads. The detector provides high gas gain, good energy resolution and the resistive layer assures spark protection to the electronics. This assembly could be combined with modern pixel array electronic ASICs. This readout organization is free on how the pixels are designed, arranged and connect…
In recent years, micropattern gaseous detectors, which comprise a two-dimensional readout structure within one PCB layer, received significant attention in the development of precision and cost-effective tracking detectors in medium and high energy physics experiments. In this article, we present for the first time a systematic performance study of the signal characteristics of a resistive strip micromegas detector with a two-dimensional readout, based on test-beam and X-ray measurements. In particular, comparisons of the response of the two independent readout-layers regarding their signal sh…
T2K is a long baseline neutrino experiment that has been operating since 2009 providing some of the world-wide leading measurements for neutrino oscillation parameters. An upgrade for the Near Detector, ND280, of T2K has been proposed. It includes the installation of two new Time Projection Chambers (TPC) based on a new read-out technology: the resistive anode MicroMegas (RMM). This technology is expected to reduce the number of electronic channels while maintaining or improving the current ND280 TPCs' bulk MicroMegas perfomance. A series of tests have been performed and further studies are on…
An upgrade of the Near Detector of the T2K long baseline neutrino oscillation experiment, ND280, has been proposed. This upgrade will include two new Time Projection Chambers, each equipped with 16 resistive MicroMegas modules for gas amplification. A first prototype of resistive MicroMegas has been designed, built, installed in the HARP field cage, and exposed to a beam of charged particles at CERN. The data have been used to characterize the performances of the resistive MicroMegas module. A spatial resolution of 300 $μm$ and a deposited energy resolution of 9% were observed for horizontal e…
Piggyback Micromegas consists in a novel readout architecture where the anode element is made of a resistive layer on a ceramic substrate. The resistive layer is deposited on the thin ceramic substrate by an industrial process which provides large dynamic range of resistivity (10$^6$ to 10$^{10}$\,M$Ω$/square). The particularity of this new structure is that the active part is entirely dissociated from the read-out element. This gives a large flexibility on the design of the anode structure and the readout scheme. Without significant loss, signals are transmitted by capacitive coupling to the …
The Muon ATLAS Micromegas Activity (MAMMA) focuses on the development and testing of large-area muon detectors based on the bulk-Micromegas technology. These detectors are candidates for the upgrade of the ATLAS Muon System in view of the luminosity upgrade of Large Hadron Collider at CERN (sLHC). They will combine trigger and precision measurement capability in a single device. A novel protection scheme using resistive strips above the readout electrode has been developed. The response and sparking properties of resistive Micromegas detectors were successfully tested in a mixed (neutron and g…
We describe here various detectors designs: GEM type, MICROMEGAStype, PPACtype as well as cascaded detectors made of a resistive mesh manufactured from a resistive Kapton foil, (20 microns thick, resistivity a few MOhm per square) by a laser drilling technique. As in any other micropattern detectors the maximum achievable gas gain of these detectors is restricted by the Raether limit, however, the resistive mesh makes them and the front end electronics fully spark protected. This approach could be an alternative or complimentary to the ongoing efforts in developing MICROMEGAS and GEMs with res…
Micromegas technology is a promising candidate to replace Atlas forward muon chambers -tracking and trigger- for future HL-LHC upgrade of the experiment. The increase on background and pile-up event probability requires detector performances which are currently under studies in intensive RD activities. We studied performances of four different resistive Micromegas detectors with different read-out strip pitches. These chambers were tested using \sim120 GeV momentum pions, at H6 CERN-SPS beam line in autumn 2010. For a strip pitch 500 micrometers we measure a resolution of \sim90 micrometers an…
The Muon ATLAS MicroMegas Activity (MAMMA) focuses on the development and testing of large-area muon detectors based on the bulk-Micromegas technology. These detectors are candidates for the upgrade of the ATLAS Muon System in view of the luminosity upgrade of Large Hadron Collider at CERN (sLHC). They will combine trigger and precision measurement capability in a single device. A novel protection scheme using resistive strips above the readout electrode has been developed. The response and sparking properties of resistive Micromegas detectors were successfully tested in a mixed (neutron and g…
With the tenfold luminosity increase envisaged at the HL-LHC, the background (photons, neutrons, ...) and the event pile-up probability are expected to increase in proportion in the different experiments, especially in the forward regions like, for instance, the muons chambers of the ATLAS detector. Detectors based on the Micromegas principle should be good alternatives for the detector upgrade in the HL-LHC framework because of a good spatial (<100 \mum) and time (few ns) resolutions, high-rate capability, radiation hardness, good robustness and the possibility to build large areas. The aim o…
Performance Optimization and Characterization of 7-pad Resistive PICOSEC Micromegas Detectors
Aristotle University of Thessaloniki（塞萨洛尼基亚里士多德大学）；Ludwig Maximilian University of Munich（慕尼黑路德维希-马克西米利安大学）；CERN（欧洲核子研究中心）；Stony Brook University（石溪大学）；NCSR Demokritos（德墨忒尔国家科学研究中心）；University of Bonn（波恩大学）；Laboratório de Instrumentação e Física Experimental de Partículas (LIP)（粒子物理实验与仪器实验室）；University of Helsinki（赫尔辛基大学）；Jefferson Lab（杰弗逊实验室）；University of Zagreb（萨格勒布大学）；University of Science and Technology of China（中国科学技术大学）；CEA-List, Diamond Sensors Laboratory, CEA-Saclay（CEA-列表，钻石传感器实验室，CEA-萨克雷）；National Technical University of Athens（雅典国立技术大学）；Ruđer Bošković Institute（鲁德·博什科维奇研究所）；University of Virginia（弗吉尼亚大学）
The second phase of the T2K experiment is expected to start data taking in autumn 2022. An upgrade of the Near Detector (ND280) is under development and includes the construction of two new Time Projection Chambers called High-Angle TPC (HA-TPC). The two endplates of these TPCs will be paved with eight Micromegas type charge readout modules. The Micromegas detector charge amplification structure uses a resistive anode to spread the charges over several pads to improve the space point resolution. This innovative technique is combined with the bulk-Micromegas technology to compose the "Encapsula…
Resistive-anode micromegas detectors are in development since several years, in an effort to solve the problem of sparks when working at high flux and high ionizing radiation like in the HL-LHC (up to ten times the luminosity of the LHC). They have been chosen as one of the technologies that will be part of the ATLAS New Small Wheel project (forward muon system). An ageing study is mandatory to assess their capabilities to handle the HL-LHC environment on a long-term period. A prototype has been exposed to several types of irradiation (X-rays, cold neutrons, $^{60}$Co gammas and alphas) above …
Resistive-anode Micromegas detectors are in development since several years, in an effort to solve the problem of sparks when working in high flux and high radiations environment like in the HL-LHC (ten times the luminosity of the LHC). They have been chosen as one of the technologies that will be part of the ATLAS New Small Wheel project (forward muon system). An ageing study is mandatory to assess their capabilities to handle the HL-LHC environment on a long-term period. A prototype has been exposed to several types of irradiations (X-rays, cold neutrons, 60 Co gammas) up to an equivalent HL…
Design and Performance of a 96-channel Resistive PICOSEC Micromegas Detector for ENUBET
Aristotle University of Thessaloniki（塞萨洛尼基亚里士多德大学）；Ludwig Maximilian University of Munich（慕尼黑路德维希-马克西米利安大学）；CERN（欧洲核子研究组织）；Stony Brook University（石溪大学）；NCSR Demokritos（德墨忒勒斯国家科学研究中心）；University of Bonn（波恩大学）；LIP（粒子物理与实验仪器实验室）；University of Helsinki（赫尔辛基大学）；Jefferson Lab（杰斐逊实验室）；University of Zagreb（萨格勒布大学）；University of Science and Technology of China（中国科学技术大学）；CEA-Saclay（法国原子能和替代能源委员会萨克雷中心）；National Technical University of Athens（雅典国立技术大学）；Ruđer Bošković Institute（鲁德·博什科维奇研究所）；University of Virginia（弗吉尼亚大学）
We present the performance of multiplexed XY resistive Micromegas detectors tested in the CERN SPS 100 GeV/c electron beam at intensities up to 3.3 $\times$ 10$^5$ e$^- $/(s$\cdot$cm$^2$). So far, all studies with multiplexed Micromegas have only been reported for tests with radioactive sources and cosmic rays. The use of multiplexed modules in high intensity environments was not explored due to the effect of ambiguities in the reconstruction of the hit point caused by the multiplexing feature. At the beam intensities analysed in this work and with a multiplexing factor of 5, more than 50% lev…
In this paper, the design and the performance of a prototype detector based on MicroMegas technology with two detection planes in a common gas volume is discussed. The detector is suited for the forward region of LHC detectors, addressing the high-rate environment and limited available space. Each detection plane has an active area of 9x9 cm^2 with a two-dimensional strip readout and is separated by a common gas region with a height of 14 mm. A micro-mesh, working as a cathode, is placed in the middle of the common gas volume separating it into two individual cells. This setup allows for an an…
We report on the construction and initial performance studies of two micromegas detector quadruplets with an area of 0.5 m$^2$. They serve as prototypes for the planned upgrade project of the ATLAS muon system. Their design is based on the resistive-strip technology and thus renders the detectors spark tolerant. Each quadruplet comprises four detection layers with 1024 readout strips and a strip pitch of 415 $μ$m. In two out of the four layers the strips are inclined by $\pm$1.5$^{\circ}$ to allow for the measurement of a second coordinate. We present the detector concept and report on the exp…
The Micro-Pattern Gaseous Detectors (MPGD) have been widely adopted in nuclear and particle physics experiments, for their fast response and other excellent characteristics. To achieve the required signal strength and detection efficiency, sometimes they are operated at a high voltage range. This often challenges the limit of high voltage stability of the detector. Discharge in gaseous detectors is a complex process and involves several responsible factors. The microscopic geometrical structures of the MPGDs may itself sometimes induce discharges. In this study, we are numerically investigatin…
The paper summarizes our latest progress in the development of newly introduced micro pattern gaseous detectors with resistive electrodes. These resistive electrodes protect the detector and the front-end electronics in case of occasional discharges and thus make the detectors very robust and reliable in operation. As an example, we describe in greater detail a new recently developed GEM-like detector, fully spark-protected with electrodes made of resistive kapton. We discovered that all resistive layers used in these studies (including kapton), that are coated with photosensitive layers, such…
Characterization of Charge Spreading and Gain of Encapsulated Resistive Micromegas Detectors for the Upgrade of the T2K Near Detector Time Projection Chambers
New Micromegas (Micro-mesh gaseous detectors) are being developed in view of the future physics projects planned by the COMPASS collaboration at CERN. Several major upgrades compared to present detectors are being studied: detectors standing five times higher luminosity with hadron beams, detection of beam particles (flux up to a few hundred of kHz/mm^{2}, 10 times larger than for the present Micromegas detectors) with pixelized read-out in the central part, light and integrated electronics, and improved robustness. Two solutions of reduction of discharge impact have been studied, with Microme…
In this report we discuss static and time dependent electric fields in detector geometries with an arbitrary number of parallel layers of a given permittivity and weak conductivity. We derive the Green's functions i.e. the field of a point charge, as well as the weighting fields for readout pads and readout strips in these geometries. The effect of 'bulk' resistivity on electric fields and signals is investigated. The spreading of charge on thin resistive layers is also discussed in detail, and the conditions for allowing the effect to be described by the diffusion equation is discussed. We ap…
The micromegas technology is a promising candidate to replace the forward muon chambers for the luminosity upgrade of ATLAS. The LHC accelerator luminosity will be five times the nominal one, increasing background and pile-up event probability. This requires detector performances which are currently under study in intensive R&D activities. Aging is one of the key issues for a high-luminosity LHC application. For this reason, we study the properties of resistive micromegas detectors under intense X-ray radiation and under thermal neutrons in different CEA-Saclay facilities. This study is comple…
Micro-pattern gas detectors, such as the Gas Electron Multiplier (GEM) and the Micromegas need narrow high density anode readout elements to achieve good spatial resolution. A high-density anode readout would require an unmanageable number of electronics channels for certain potential micro-detector applications such as the Time Projection Chamber. We describe below a new technique to achieve good spatial resolution without increasing the electronics channel count in a modified micro-detector outfitted with a high surface resistivity anode readout structure. The concept and preliminary measure…
We describe the most recent efforts made by various groups in implementing resistive electrodes in micropattern gaseous detectors with the aim to combine in the same design the best features of RPCs (for the example, their robustness and spark protection property) with the high granularity and thus the good position resolution offered by microelectronic technology. In the stream of this activity, we have recently developed two novel detectors with resistive electrodes: one was based on resistive micromeshes and the second one is a MSGC with resistive electrodes. We have demonstrated that the r…
The Micro Pixel Chamber (mu-PIC) using resistive electrodes has been developed and tested. The surface cathodes are made from resistive material, by which the electrical field is reduced when large current is flowed. Two-dimensional readouts are achieved by anodes and pickup electrodes, on which signals are induced. High gas gain (> 60000) was measured using 55Fe (5.9 keV) source, and very intensive spark reduction was attained under fast neutron. The spark rate of resistive mu-PIC was only 10^-4 times less than that of conventional mu-PIC at the gain of 10^4. With these developments, a new MP…
In the last few years our group have focused on developing various designs of spark-protected micropattern gaseous detectors featuring resistive electrodes instead of the traditional metallic ones: resistive microstrip counters, resistive GEM, resistive MICROMEGAS. These detectors combine in one design the best features of RPCs (spark-protection) and micropattern detectors (a high position resolution). In this paper we report the progress so far made in developing other types of resistive micropattern detectors: a microdot-microhole detector and a microgap-microstrip detector. The former detec…
The Particle And Astrophysical Xenon Experiment III (PandaX-III) is an experiment to search for the Neutrinoless Double Beta Decay (NLDBD) using 200 kg radio-pure high-pressure gaseous xenon TPC with Micromegas detectors at both ends and cathode in the middle. A small-scale TPC equipped with 7 Microbulk Micromegas detectors is developed as the prototype detector. 128 channels are readout following an X-Y design with strips of 3 mm pitch (64 channels each direction) from one Micromegas module. Highly integrated front-end electronics composed of 4 front-end cards with 1024 readout channels is de…
μRWELL-PICOSEC: Precision Timing with Resistive Micro-Well Detector
Thomas Jefferson National Accelerator Facility（托马斯·杰斐逊国家加速器设施）；IRFU, CEA, Université Paris-Saclay（IRFU, 法国原子能和替代能源委员会, 巴黎萨克雷大学）；Department of Physics, Aristotle University of Thessaloniki（塞萨洛尼基亚里士多德大学物理系）；Center for Interdisciplinary Research and Innovation (CIRI-AUTH)（跨学科研究与创新中心）；Department for Medical Physics, Ludwig Maximilian University of Munich（慕尼黑路德维希-马克西米利安大学医学物理系）；European Organization for Nuclear Research (CERN)（欧洲核子研究组织）；Dipartimento di Fisica, Università di Pavia（帕维亚大学物理系）；INFN Sezione di Pavia（意大利国家核物理研究所帕维亚分部）；Department of Physics and Astronomy, Stony Brook University（石溪大学物理与天文学系）；Institute of Nuclear and Particle Physics, NCSR Demokritos（国家科学研究中心德谟克利特研究所核与粒子物理研究所）
In this work we have developed a prototype gaseous pixel detector by combining a micromegas grid with a Timepix3 chip for the readout. The micromegas foil supported by a matrix of pillars about 50 $\mathrm{μm}$ high was manually placed on top the chip. By placing a cathode foil above the chip an ionization detector was created with a drift gap of 13.5 mm. The Timepix3 chip, thanks to the simultaneous measurement of the time-of-arrival (ToA) and charge via time-over-threshold (ToT) allows corrections to remaining timewalk effects, improving further the position resolution along the drift direct…
We have developed microstrip gas counters manufactured on standard printed circuit board and having the following features: resistive cathode strips, thin (10 micron) metallic anode strips and electrodes protected against surface discharges by a Coverlay layer at their edges. These features allow the detector to operate at gas gains as high as can be achieve with the best microstrip gas counters manufactured on glass substrates. We believe that after further developments this type of detectors can compete in some applications with other micropattern detectors, for example MICROMEGAS.
We have developed and tested several prototypes of GEM-like detectors with electrodes coated with resistive layers: CuO or CrO. These detectors can operate stably at gains close to 10E5 and they are very robust. We discovered that the cathodes of these detectors could be coated by CsI layers and in such a way the detectors gain high efficiency for the UV photons. We also demonstrated that such detectors can operate stably in the cascade mode and high overall gains (~10E6) are reachable. This opens applications in several areas, for example in RICH or in noble liquid TPCs. Results from the firs…
Advances in photocathode development for PICOSEC Micromegas precise-timing detectors
European Organization for Nuclear Research (CERN)（欧洲核子研究组织）；University of Turin（都灵大学）；Middle East Technical University（中东技术大学）；Technion - Israel Institute of Technology（以色列理工学院）；IRFU, CEA, Université Paris-Saclay（巴黎萨克雷大学CEA IRFU）；Ludwig Maximilian University of Munich（慕尼黑路德维希-马克西米利安大学）；Weizmann Institute of Science（魏茨曼科学研究所）；Università di Pavia（帕维亚大学）；INFN Sezione di Pavia（意大利国家核物理研究院帕维亚分部）；Stony Brook University（石溪大学）
The Micromegas technology is one of the most successful MPGD concepts and widely utilized in nuclear and particle physics experiments. Twenty years of research and development rendered the technology sufficiently mature to be selected as precision tracking detector for the New Small Wheel (NSW) upgrade of the ATLAS Muon spectrometer. This will be the first large scale application of Micromegas in one of the major LHC experiments. The studies on signal formation in Micromegas focuses on the microscopic signal electron loss mechanisms and the amplification processes in electron gas interaction. …
In the framework of the ATTRACT-uRANIA project, funded by the European Community, we are developing an innovative neutron imaging detector based on micro-Resistive WELL ($μ$ -RWELL) technology. The $μ$ -RWELL, based on the resistive detector concept, ensuring an efficient spark quenching mechanism, is a highly reliable device. It is composed by two main elements: a readout-PCB and a cathode. The amplification stage for this device is embedded in the readout board through a resistive layer realized by means of an industrial process with DLC (Diamond-Like Carbon). A thin layer of B$_4$C on the c…
We developed a tool for the simulation of charge transport on a conducting plate of finite dimensions. This tool is named Chani. Main motivation of developing Chani was to provide a tool for the optimization of the dimensions and resistivity of the anode electrodes in spark-protected Micropattern Gaseous Detectors (MPGD). In this thesis, we start with the general description of the LHC and the ATLAS Experiment. Then, we review the gaseous ionization detector technologies and in particular, the micromegas technology. We then present the working principles of Chani along with the example calcula…
Digital and Semi-Digital Hadronic Calorimeters (S)DHCAL were suggested for future Colliders as part of the particle-flow concept. Though studied mostly with RPC-based techniques, investigations have shown that MPGD-based sampling elements could outperform. An attractive, industry-produced, robust, particle-tracking detector for large-area coverage, e.g. in (S)DHCAL, could be the novel single-stage Resistive Plate WELL (RPWELL). It is a single-sided THGEM coupled to the segmented readout electrode through a sheet of large bulk resistivity. We summarize here the preliminary test-beam results obt…
Full Characterization of a Mock Nuclear Waste Barrel with Muon Tomography using Micromegas Detectors
CEA/Irfu, Université Paris-Saclay（法国原子能委员会/核研究与物理技术研究所，巴黎萨克雷大学）；Centro de Astropartículas y Física de Altas Energías (CAPA), Universidad de Zaragoza（高能天体粒子中心，萨拉戈萨大学）
We developed a novel design of a Micro Pixel Chamber ($μ$-PIC) with resistive electrodes for a charged-particle-tracking detector in high-rate applications. Diamond-Like Carbon (DLC) thin film is used for the cathodes. The resistivity can be controlled flexibly ($\mathrm{10^{5-7}kΩ/sq.}$) at high uniformity. The fabrication-process was greatly improved and the resistive $μ$-PIC could be operated at 10$\times$10 $\mathrm{cm^2}$. Resistors for the HV bias and capacitors for the AC coupling were completely removed by applying PCB and carbon-sputtering techniques, and the resistive $μ$-PIC became …
In this work we present a novel idea for a compact spark-protected single amplification stage Micro-Pattern Gas Detector (MPGD). The detector amplification stage, realized with a structure very similar to a GEM foil, is embedded through a resistive layer in the readout board. A cathode electrode, defining the gas conversion/drift gap, completes the detector mechanics. The new structure, that we call Resistive-WELL (R-WELL), has some characteristics in common with previous MPGDs, such as C.A.T. and WELL, developed more than ten years ago. The prototype object of the present study has been reali…
The TPC for the International Linear Collider (ILC) will need to measure about 200 track points with a transverse resolution close to 100 microns. The resolution goal is beyond the capability of the conventional proportional wire/cathode pad TPC and Micro-Pattern Gas Detectors (MPGD) are being developed to meet the challenge. The standard MPGD readout techniques will, however, have difficulty in achieving the ILC-TPC resolution goal with the 2 mm x 6 mm pads as was initially envisioned. Proposals for smaller width pads will improve the resolution but will require a larger number of readout cha…
We present a new technology for the shaping of the electric field in Time Projection Chambers (TPCs) using a carbon-loaded polyimide foil. This technology allows for the minimisation of passive material near the active volume of the TPC and thus is capable to reduce background events originating from radioactive decays or scattering on the material itself. Furthermore, the high and continuous electric resistivity of the foil limits the power dissipation per unit area and minimizes the risks of damages in the case of an electric field breakdown. Replacing the conventional field cage with a resi…
