Multi-gap Resistive Plate Chamber Research Articles

Multigap RPC time resolution to 511 keV annihilation photons

The time resolution of Multigap Resistive Plate Chambers (MRPCs) to 511keV gamma rays has been investigated using a 22Na source and four detectors. The MRPCs time resolution has been derived from the Time-of-Flight information, measured from pairs of space correlated triggered events. A GEANT4 simulation has been performed to analyze possible setup contributions and to support experimental results. A time resolution (FWHM) of 312ps and 376ps has been measured for a single MRPC with four 250μm gas gaps by considering respectively one and two independent pairs of detectors.These values, endorsed by the GEANT4 simulation, represent a good result compared to those reported in the literature.

Development of TOF-PET detectors based on the Multi-Gap Resistive Plate Chambers

We describe the development, construction and preliminary results obtained with medium-size Multi-Gap Resistive Plate Chambers prototypes designed to detect and localize 511keV photons for Positron Emission Tomography imaging applications. The devices are intended for in-beam monitoring of the treatment plans throughout deep tumor therapy with hadron beams; emphasis is put on achieving coincidence time resolutions of few hundred ps, in order to exploit optimized reconstruction algorithm and reduce the heavy non-correlated background contributions distinctive of this operation. Using technologies developed for high energy physics experiments, the detectors can be built for covering large areas, thus leading the way to the conception of full-body PET systems at low cost.

A high time and spatial resolution MRPC designed for muon tomography

A prototype of cosmic muon scattering tomography system has been set up in Tsinghua University in Beijing. Multi-gap Resistive Plate Chamber (MRPC) is used in the system to get the muon tracks. Compared with other detectors, MRPC can not only provide the track but also the Time of Flight (ToF) between two detectors which can estimate the energy of particles. To get a more accurate track and higher efficiency of the tomography system, a new type of high time and two-dimensional spatial resolution MRPC has been developed. A series of experiments have been done to measure the efficiency, time resolution and spatial resolution. The results show that the efficiency can reach 95% and its time resolution is around 65 ps. The cluster size is around 4 and the spatial resolution can reach 200 μ m.

Simulation of the BESIII endcap time of flight upgrade

The results of a full simulation of an endcap time of flight detector upgrade based on multigap resistive plate chambers for the BESIII experiment are presented. The simulation and reconstruction software is based on Geant4 and has been implemented into the BESIII Offline Software System. The results of the simulations are compared with beam test results and it is shown that a total time resolution σ of about 80ps can be achieved allowing for a pion and kaon separation up to momenta of 1.4GeV/c at a 95% confidence level.

A multigap resistive plate chamber array for the Extreme Energy Events project

The Extreme Energy Events (EEE) Project is a Centro Fermi - CERN - INFN - MIUR Collaboration Project for the study of extremely high energy cosmic rays, which exploits the Multigap Resistive Plate Chamber (MRPC) technology. The excellent time resolution and good tracking capability of this kind of detector allows us to study Extensive Air Showers (EAS) with an array of MRPC telescopes distributed across the Italian territory. Each telescope is installed in a high school, with the further goal to introduce students to particle and astroparticle Physics. The status of the experiment and the results obtained are reported.

The CBM Time-of-Flight wall — a conceptual design

Charged hadron identification in the Compressed Baryonic Matter experiment (CBM) is realized via the Time-of-Flight method [1]. For this purpose the CBM-ToF collaboration designed a Time-of-Flight wall composed of Multi-gap Resistive Plate Chambers (MRPCs). Due to the high interaction rate in CBM of 10 MHz the key challenge is the development of high rate MRPCs above 25 kHz/cm2 which become possible after the development of low resistive glass with extremely good quality. In this article we present the actual conceptual design of the ToF-wall which is subdivided in three parts namely the outer wall, the inner wall and the forward zone that are discussed in detail.

Performance simulation of a MRPC-based PET imaging system

The less expensive and high resolution Multi-gap Resistive Plate Chamber (MRPC) opens up a new possibility to find an efficient alternative detector for the Time of Flight (TOF) based Positron Emission Tomography, where the sensitivity of the system depends largely on the time resolution of the detector. In a layered structure, suitable converters can be used to increase the photon detection efficiency. In this work, we perform a detailed GEANT4 simulation to optimize the converter thickness towards improving the efficiency of photon conversion. A Monte Carlo based procedure has been developed to simulate the time resolution of the MRPC-based system, making it possible to simulate its response for PET imaging application. The results of the test of a six-gap MRPC, operating in avalanche mode, with 22Na source have been discussed.

Particle IDentification with the ALICE Time-Of-Flight detector at the LHC

The main physics goal of ALICE (A Large Ion Collider Experiment) is the study of the physics of strongly interacting matter at extreme energy densities, where the formation of a new phase of matter, the Quark-GluonPlasma (QGP), is expected. One of the most important aspect of ALICE is the Particle IDentification (PID) performed by combining different identification techniques. The time measurement with the Time-Of-Flight (TOF) detector, in conjunction with the momentum and track length measured by the tracking detectors is used to calculate the particle mass in the intermediate momentum range from 0.3 up to a few GeV/c. The TOF system covers an area of 141 m2 and consists of Multi-gap Resistive Plate Chambers (MRPC), that allow excellent performances in terms of intrinsic time resolution (of the order of few tens of ps) and overall efficiency (close to 100%).The ALICE TOF system has shown very stable operation during the firstthree years of collisions at the LHC, reaching the design goal of 80ps time resolution. The performance and main physics results will bereported.

MRPC detector for the BESIII E-TOF upgrade

An end-cap Time-of-Flight (E-TOF) system with highergranularity compare to the current E-TOF and intrinsic time resolution ofbetter than 50 ps will extend the K/π separation (2σ) momentumrange to 1.4 GeV/c and enhance the physics capability of BeijingSpectrometer (BESIII). A R&D project was carried out aiming at upgradingthe current BESIII E-TOF with the Multi-gap Resistive Plate Chamber (MRPC).The beam test for the MRPC prototype, together with the custom-designedFront End Electronics (FEE) and TDC boards, was performed at the BEPC E3line in the last years. The test results show that the detector has stableperformance at different positions and working High Voltage (HV). A timeresolution of better than 50 ps can be achieved. The different performancebetween pion and proton events is also discussed.

An encoding readout method used for Multi-gap Resistive Plate Chambers (MRPCs) for muon tomography

A muon tomography facility has been built in Tsinghua University. Because of the low flux of cosmic muon, an encoding readout method, based on the fine-fine configuration, was implemented for the 2880 channels induced signals from the Multi-gap Resistive Plate Chamber (MRPC) detectors. With the encoding method, the number of the readout electronics was dramatically reduced and thus the complexity and the cost of the facility was reduced, too. In this paper, the details of the encoding method, and the overall readout system setup in the muon tomography facility are described. With the commissioning of the facility, the readout method works well. The spatial resolution of all MRPC detectors are measured with cosmic muon and the preliminary imaging result are also given.

Study on high rate MRPC for high luminosity experiments

Multi-gap Resistive Plate Chambers (MRPC) has been used to construct time-of-flight system in the field of nuclear and particle physics, due to their high-precision timing properties, high efficiency, reliability and coverage of large area. With the increase of accelerator luminosity, MRPCs have to withstand particle fluxes up to several tens of kHz/cm2 in view of the next generation physics experiments, such as the SIS-100/300 at FAIR-CBM, SoLID at JLab and NICA at JINR. But the MRPC assembled with float glass has very low rate capability not exceeding some hundreds of Hz/cm2. Two possible solutions for increasing rate capability, one is to reduce the bulk resistivity of glass and the other is to reduce the electrode thickness. Tsinghua University has done R&D on high rate MRPC for many years. A special low resistive glass with bulk resistivity around 1010Ω.cm was developed. We also studied the rate capability changes with glass thickness. In this paper we describe the performance of low resistive glass and two kinds of high rate MRPC (Pad readout and Strip readout) tested by deuterium beams. The results show that the tolerable particle flux can reach 70 kHz/cm2. In the mean time, MRPCs assembled with three thickness (0.7 mm, 0.5 mm and 0.35 mm) of float glass were also tested with deuteron beams, the results show that the three detectors can afford particle rate up to 500 Hz/cm2, 0.75 kHz/cm2 and 3 kHz/cm2, respectively.

Cosmic rays Monte Carlo simulations for the Extreme Energy Events Project

The Extreme Energy Events Project (EEE Project) is an innovative experiment to study very high energy cosmic rays by means of the detection of the associated air shower muon component. It consists of a network of tracking detectors installed inside Italian High Schools. Each tracking detector, called EEE telescope, is composed of three Multigap Resistive Plate Chambers (MRPCs). At present, 43 telescopes are installed and taking data, opening the way for the detection of far away coincidences over a total area of about 3 × 105 km2. In this paper we present the Monte Carlo simulations that have been performed to predict the expected coincidence rate between distant EEE telescopes.

Efficiency determination of resistive plate chambers for fast quasi-monoenergetic neutrons

Composite detectors made of stainless steel converters and multigap resistive plate chambers have been irradiated with quasi-monoenergetic neutrons with a peak energy of 175MeV. The neutron detection efficiency has been determined using two different methods. The data are in agreement with the output of Monte Carlo simulations. The simulations are then extended to study the response of a hypothetical array made of these detectors to energetic neutrons from a radioactive ion beam experiment.

Test of high time resolution MRPC with different readout modes for the BESIII upgrade

In order to further enhance the particle identification capability of the Beijing Spectrometer (BESIII), it is proposed to upgrade the current end-cap time-of-flight (eTOF) detector with multi-gap resistive plate chamber (MRPC). The prototypes, together with the front end electronics (FEE) and time digitizer (TDIG) module have been tested at the E3 line of Beijing Electron Positron Collider (BEPCII) to study the difference between the single and double-end readout MRPC designs. The time resolutions (sigma) of the single-end readout MRPC are 47/53ps obtained by 600MeV/c proton/pion beam, while that of the double-end readout MRPC is 40ps (proton beam). The efficiencies of three MRPC modules tested by both proton and pion beam are better than 98%. For the double-end readout MRPC, no incident position dependence is observed.

Particle identification with the ALICE Time-Of-Flight detector at the LHC

High performance Particle Identification system (PID) is a distinguishing characteristic of the ALICE experiment at the CERN Large Hadron Collider (LHC). Charged particles in the intermediate momentum range are identified in ALICE by the Time-Of-Flight (TOF) detector. The TOF exploits the Multi-gap Resistive Plate Chamber (MRPC) technology, capable of an intrinsic time resolution at the level of few tens of ps with an overall efficiency close to 100% and a large operation plateau. The full system is made of 1593 MRPC chambers with a total area of 141m2, covering the pseudorapidity interval [−0.9,+0.9] and the full azimuthal angle.The ALICE TOF system has shown very stable operation during the first 3years of collisions at the LHC. In this paper a summary of the system performance as well as main results with data from collisions will be reported.

Status and Physics Opportunities of the STAR Heavy Flavor Tracker and the Muon Telescope Detector Upgrades

The STAR Collaboration will complete the Heavy Flavor Tracker (HFT) and the Muon Telescope Detector (MTD) upgrades by 2014. HFT utilizes the state-of-art active pixel detector technology, which will greatly enhance the STAR physics capabilities by measuring heavy quark yield, collectivity and correlations via the topological reconstruction of charmed hadrons over a wide momentum range. The MTD is based on the long Multi-Gap Resistive Plate Chamber detector technology designed to measure muons penetrating the bulk of other detectors and the magnet yoke. It will enable STAR to study di-muon and electron-muon correlations and enhance heavy quarkonium studies. With the addition of these upgrades, STAR is well suited to perform precise measurements of production as well as correlations of rare probes (heavy flavors, dileptons) to systematically investigate the quark-gluon plasma properties at RHIC. For Run 13 63% of the MTD has been installed and data have been taken. Prototype PXL sectors (30% coverage) have also been installed and commissioned. Anticipated physics results and current status of these upgrades is reported.

Prototype of time digitizing system for BESIII endcap TOF upgrade

The prototype of a time digitizing system for the BESIII endcap TOF (ETOF) upgrade is introduced in this paper. The ETOF readout electronics has a distributed architecture. Hit signals from the multi-gap resistive plate chamber (MRPC) are signaled as LVDS by front-end electronics (FEE) and are then sent to the back-end time digitizing system via long shield differential twisted pair cables. The ETOF digitizing system consists of two VME crates, each of which contains modules for time digitization, clock, trigger, fast control, etc. The time digitizing module (TDIG) of this prototype can support up to 72 electrical channels for hit information measurement. The fast control (FCTL) module can operate in barrel or endcap mode. The barrel FCTL fans out fast control signals from the trigger system to the endcap FCTLs, merges data from the endcaps and then transfers to the trigger system. Without modifying the barrel TOF (BTOF) structure, this time digitizing architecture benefits from improved ETOF performance without degrading the BTOF performance. Lab experiments show that the time resolution of this digitizing system can be lower than 20 ps, and the data throughput to the DAQ can be about 92 Mbps. Beam experiments show that the total time resolution can be lower than 45 ps.

123: Multigap Resistive Plate Chambers as a Positron Emission Tomography detector

123: Multigap Resistive Plate Chambers as a Positron Emission Tomography detector

MRPC detector for the upgrade of BESIII E-TOF

An end-cap Time-of-Flight (E-TOF) system with higher granularity and intrinsic time resolution of better than 50 ps will extend the K/pion separation (2 sigma) pT range to 1.4 GeV/c and enhance the physics capability of Beijing Spectrometer (BESIII). A R&D work was carried out aiming at upgrading the current BESIII E-TOF with the Multi-gap resistive Plate Chamber (MRPC) detector. The latest best test for the prototype MRPC, together with the custom designed Front End Electronics (FEE) and TDC boards, was performed at the BEPC E3 line in July 2012. The test results show that time resolution of less than 50 ps can be achieved with such a system.

A High-Density Time-to-Digital Converter Prototype Module for BES III End-Cap TOF Upgrade

This paper describes a high-precision time measurement module for the end-cap time-of-flight (ETOF) upgrade of the Beijing Spectrometer (BES III). ETOF is scheduled to be upgraded with the multi-gap resistive plate chambers (MRPCs) instead of a scintillator. The new ETOF of BES III will have 1728 readout channels, which is a big challenge for the readout electronics. The time resolution of the readout electronics system is required to be better than 25 ps. A 9U VME module with 72 time measurement channels is designed to perform the time measurement. The signals, which are produced by the detector and then amplified and discriminated by the attached frontend electronics, are sent to this module. The module, which is named TDIG, uses the CERN HPTDC to achieve high-precision time measurement. There are nine HPTDC chips on the module, and each provides eight channels to realize 72 channels. A series of experiment tests show that the time resolution of the TDIG module is better than 20 ps. We have constructed a beam test system composed of six plastic scintillators, two MRPC modules, and ETOF prototype electronics, which testifies to the time resolution expected. An overall time resolution of less than 45 ps for beam events has been achieved.