Muon Tracking System Research Articles

Exploring the potential of muon radiography for blast furnace assessments: advancements in non-invasive imaging and structural analysis

The BLEMAB European project (BLast furnace stack density Estimation through online Muon ABsorption measurements), the evolution of the previous Mu-Blast European project, is designed to investigate in detail the capability of muon radiography techniques applied to the imaging of the inner zone of a blast furnace. In particular, the goal of this collaboration is to characterize the internal region (so-called cohesive zone) where the slowly downward-moving material begins to soften and melt, which plays an important role in the performance of the blast furnace itself. In this contribution, we describe the state-of-the-art of the muon tracking system which is currently being developed and installed at a blast furnace on the ArcelorMittal site in Bremen (Germany). Moreover, we will present the GEANT4 simulation framework devised for this application together with the simulation results. Finally, we will show the possible contribution of multiple scattering effects to such peculiar applications.

BLEMAB European project: muon imaging technique applied to blast furnaces

The BLEMAB European project (BLast furnace stack density Estimation through on-line Muon ABsorption measurements), evolution of the previous Mu-Blast European project, is designed to investigate in detail the capability of muon radiography techniques applied to the imaging of a blast furnace’s inner zone. In particular, the geometry and size of the so called “cohesive zone”, i.e. the spatial zone where the slowly downward moving material begins to soften and melt, that plays an important role in the performance of the blast furnace itself. Thanks to the high penetration power of the natural cosmic ray muon radiation, muon transmission radiography represents an appropriate non-invasive methodology for imaging large high-density structures such as blast furnaces, whose linear size can be up to a few tens of meters. A state-of-the-art muon tracking system, whose design profits from the long experience of our collaboration in this field, is currently under development and will be installed in 2022 at a blast furnace on the ArcelorMittal site in Bremen (Germany) for many months. Collected data will be exploited to monitor temporal variations of the average density distribution inside the furnace. Muon radiography results will also be compared with measurements obtained through an enhanced multipoint probe and standard blast furnace models.

MRPC technology for muon tomography

Muon tomography is an innovative high-Z material detection technology developed in recent years. The most crucial part of this technology is the high position resolution detectors used for the muon track reconstruction. Multi-Gap Resistive Plate Chambers (MRPCs in the following) are gaseous detectors first developed at CERN in middle 1990s. Considering their characteristics in terms of high efficiency, low cost, robust structure, and excellent position resolution, MRPC became the detector of choice for the TUMUTY (Tsinghua University cosmic ray muon tomography facility) system built in 2012. This paper features a summary about the latest developments on MRPC technology for muon tomography. After the success of the TUMUTY prototype, researches were carried out on larger sensitive area position resolution MRPCs with 2-D readout, and on environment-friendly sealed MRPCs (SMRPC) for industrial applications and future muon tomography systems. It was studied how encoding readout methods and external environment influence the performance of MRPC detectors. Also, an MRPC simulation frame and new data processing methods were both developed, which have provided useful information on optimal design of the future position resolution MRPCs and muon tracking systems.

Construction and test of the SM1 MicroMegas chambers for the upgrade of the forward muon spectrometer of the ATLAS experiment

Abstract MICRO MEsh GASeous structure chambers, MicroMegas (MM (Giomataris et al., 1996 [1] )), is an innovative design concept for Micro-Pattern Gaseous Detectors, designed in order to provide a high spatial resolution and to cope with highly irradiated environments. These chambers have been chosen as new precision tracking detectors for the upgrade of the forward muon spectrometer of the ATLAS experiment during Long Shutdown 2 (LS2, 2019–2020). MM trapezoidal detector modules, with areas of 2–3 m 2 , will be part of the two New Small Wheels (NSW (ATLAS collaboration, 2013 [2] )) composing the innermost station of the ATLAS muon tracking system. ATLAS MM detectors are composed out of 4 read-out (RO) layers, two for the reconstruction of the precision coordinate and two with stereo reading ( ± 1 . 5 °) for the reconstruction of the second coordinate. MM chambers are designed to provide a resolution better that 100 μ m on the precision coordinate with an efficiency of at least 95% per single plane for a rate capability up to 15 kHz/cm 2 , in presence of magnetic fields up to 0.3 T. The Istituto Nazionale di Fisica Nucleare (INFN) is deeply involved in the construction of these chambers and their validation at the Cosmic Ray Stand (CRS) in the Frascati INFN site (LNF). Preliminary results on the tests performed on the INFN SM1 prototypes are presented. Copyright 2018 CERN for the benefit of the ATLAS Collaboration. CC-BY-4.0 license.

A stand-alone 3D muon tracking system based on Silicon Photomultipliers

We present a muon tracking system based on the use of plastic scintillator strips and Silicon Photomultipliers (SiPMs). Originally intended to be used mainly in outreach activities, the detector became an effective instrument to perform muon flux intensity measurements and for muon transmission imaging applications. It consists of two independent orthogonal views, each one made of 10 planes and containing 10 detection channels per plane. A custom electronics has been designed to bias and readout all the 200 SiPMs in the detector, to generate the trigger logic pattern and to control the working parameters. Thanks to an on-board data acquisition system, standalone data taking is possible with the addition of a computer. Commissioning and performance of the detector are presented, along with preliminary results concerning the first data taking on Saadiyat Island, Abu Dhabi, with the aim of measuring the local cosmic ray flux and to assess its muon transmission imaging capability.

Long term performance studies of large oil-free bakelite resistive plate chamber

Several high energy physics and neutrino physics experiments worldwide require large-size RPCs to cover wide acceptances. The muon tracking systems in the Iron calorimeter (ICAL) experiment in the India based Neutrino Observatory (INO), India and the near detector in Deep Underground Neutrino Experiment (DUNE) at Fermilab are two such examples. A single gap bakelite RPC of dimension 240 cm × 120 cm, with gas gap of 0.2 cm, has been built and tested at Variable Energy Cyclotron Centre, Kolkata, using indigenous materials procured from the local market. No additional lubricant, like oil has been used on the electrode surfaces for smoothening. The chamber is in operation for > 365 days. We have tested the chamber for its long term operation. The leakage current, bulk resistivity, efficiency, noise rate and time resolution of the chamber have been found to be quite stable during the testing peroid. It has shown an efficiency > 95% with an average time resolution of ∼ 0.83 ns at the point of measurement at ∼ 8700 V throughout the testing period. Details of the long term performance of the chamber have been discussed.

Design and Construction of Large Size Micromegas Chambers for the ATLAS Upgrade of the Muon Spectrometer

Large area Micromegas detectors will be employed for the first time in high-energy physics experiments. A total surface area of about $150~\text {m}^{2}$ of the forward regions (pseudo-rapidity coverage, $1.3 \,\, { ) of the Muon Spectrometer of the ATLAS detector at LHC will be equipped with 8-layer Micromegas modules. Each module extends over a surface from 2 to $3~\text {m}^{2}$ for a total active area of $1200~\text {m}^{2}$ . Together with the small strip Thin Gap Chambers they will compose the two New Small Wheels (NSW), which will replace the innermost stations of the ATLAS endcap muon tracking system in the 2018/19 shutdown. In order to achieve a 15% transverse momentum resolution for 1 TeV muons, in addition to an excellent intrinsic position resolution, the mechanical precision of each plane of the assembled module must be 30 microns along the precision coordinate and 80 microns perpendicular to the chamber. All readout planes are segmented into strips with a pitch of 450 microns for a total of 8180 strips per plane and more than 2 million channels for the NSW. In two of the four planes the strips are inclined by ±1.5° and provide a measurement of the second coordinate. The design and construction procedure of the Micromegas modules are presented, as well as the design for the assembly of modules onto the NSW. Emphasis is given on the methods developed to achieve the challenging mechanical precision. Measurements of deformation on chamber prototypes as a function of thermal gradients, gas over-pressure and internal stress (mesh tension and module fixation on supports) are also shown and compared to simulation. These tests were essential in the development of the final design in order to minimize the effects of deformations. During installation and operation all deformations and relative misalignments will be monitored through an optical alignment system and compensated in the tracking software.

Testing the prototype detectors for the muon tracking system of the CBM experiment at the CERN PS accelerator

Performance of the gas-filled detector prototypes based on the GEM, TGEM, and Micromegas technologies was studied on the test beam of the CERN PS accelerator. Three-component mixtures based on Ar and He were used as the working gas. For all tested detector prototypes, the gas amplification factors were measured, and the detection efficiencies, cluster distributions, and the radii of the charge cloud collected on the readout electrode were estimated.

Development and test of the DAQ system for a Micromegas prototype to be installed in the ATLAS experiment

A Micromegas (MM) quadruplet prototype with an active area of 0.5 m2 that adopts the general design foreseen for the upgrade of the innermost forward muon tracking systems (Small Wheels) of the ATLAS detector in 2018-2019, has been built at CERN and is going to be tested in the ATLAS cavern environment during the LHC RUN-II period 2015-2017.The integration of this prototype detector into the ATLAS data acquisition system using custom ATCA equipment is presented. An ATLAS compatible Read Out Driver (ROD) based on the Scalable Readout System (SRS), the Scalable Readout Unit (SRU), will be used in order to transmit the data after generating valid event fragments to the high-level Read Out System (ROS). The SRU will be synchronized with the LHC bunch crossing clock (40.08 MHz) and will receive the Level-1 trigger signals from the Central Trigger Processor (CTP) through the TTCrx receiver ASIC. The configuration of the system will be driven directly from the ATLAS Run Control System. By using the ATLAS TDAQ Software, a dedicated Micromegas segment has been implemented, in order to include the detector inside the main ATLAS DAQ partition. A full set of tests, on the hardware and software aspects, is presented.

A compact muon tracking system for didactic and outreach activities

We present a cosmic ray telescope based on the use of plastic scintillator bars coupled to ASD-RGB1S-M Advansid Silicon Photomultipliers (SiPM) through wavelength shifter fibers. The system is comprised of 200 electronic channels organized into 10 couples of orthogonal planes allowing the 3D reconstruction of crossing muons. Two monolithic PCB boards have been designed to bias, readout all the SiPMs enclosed in the system, to monitor the working parameters and to remotely connect the detector. To make easier the display of muon tracks to non-expert users, two LED matrices, triggered by particle interactions, have been implemented. To improve the usability of the muon telescope, a controller board unit permits to select different levels of trigger and allows data acquisition for refined analyses for the more proficient user. A first prototype, funded by INFN and deployed in collaboration with NYUAD, is operating at the Toledo Metro station of Naples, while two further detectors will be developed and installed in Abu Dhabi in the next few months.

Micromegas detectors for the muon spectrometer upgrade of the ATLAS experiment

Large area Micromegas (MM) detectors will be employed for the Muon Spectrometer upgrade of the ATLAS experiment at the LHC. A total surface of about 150m2of the forward regions of the Muon Spectrometer will be equipped with 8 layers of MM modules. Each module covers a surface area of approximately 2–3m2 for a total active area of 1200m2. Together with the small-strips Thin Gap Chambers, they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS Endcap Muon tracking system in the planned 2018/2019 shutdown. This upgrade will maintain a low pT threshold for single muons and provide excellent tracking capabilities for the HL-LHC phase. The New Small Wheel (NSW) project requires fully efficient MM chambers with spatial resolution down to 100μm, at rate capability up to about 15kHz/cm2 and operation in a moderate (highly inhomogeneous) magnetic field up to B=0.3T. The required tracking capability is provided by the intrinsic spatial resolution combined with a challenging mechanical precision. The design, recent progress in the construction and results from the substantial R& D phase (with a focus on novel technical solutions) is presented. In the R& D phase, small and medium size single layer prototypes have been built, along with, more recently, the first two MM quadruplets in a configuration very close to the final one chosen for the NSW. Several tests have been performed on these prototypes at a high-energy test-beam at CERN, to demonstrate that the achieved performances fulfil the requirements. Recent tests applying various configuration and operating conditions are presented.

Testing the prototype detectors for the muon tracking system of the CBM experiment on the proton beam of the PNPI accelerator at high counting rates

Performance of the gas-filled detector prototypes based on the GEM, TGEM, and Micromegas technologies was studied with the aim of selecting variants for tracking detectors of the muon system for the CBM Experiment. The study was performed on the test beam of the proton accelerator at the Petersburg Nuclear Physics Institute (PNPI). Three-component mixtures based on Ar and He were used as the working gas. For all tested detector prototypes, the detection efficiencies were measured, and the modification of the amplitude spectra as a function of the incident beam intensity was investigated.

A study of the coordinate gas-filled detectors based on the Micromegas and Micromegas + GEM/TGEM technologies for the muon tracking system of the CBM experiment

Prototypes of the gas-filled detectors produced on the basis of the Micromegas technology, as well as in combination with the Micromegas + GEM/TGEM structures in the multistage gas amplification circuit have been investigated with the aim of selecting variants for tracking detectors of the muon system designed for operating at high counting rates in the Compressed Baryonic Matter (CBM) experiment. Two- and three-component Ar- and He-based mixtures have been tested as the working gas. Their key characteristics are presented. The gas amplification factors are measured for various high-voltage modes, and the charge collection times determining the response speed of the tested detectors are estimated.

Muon tracking system with Silicon Photomultipliers

We report the characterisation and performance of a low cost muon tracking system consisting of plastic scintillator bars and Silicon Photomultipliers equipped with a customised front-end electronics based on a fast preamplifier network. This system can be used as a detector test bench for astroparticle physics and for educational and outreach purposes. We investigated the device behaviour in self-trigger and coincidence mode, without using LED and pulse generators, showing that with a relatively simple set up a complete characterisation work can be carried out. A high definition oscilloscope, which can easily be found in many university physics or engineering departments, has been used for triggering and data acquisition. Its capabilities have been exploited to discriminate real particles from the background.

A study of the coordinate gas-filled detectors based on the GEM and TGEM technologies for the muon tracking system of the CBM experiment

Prototypes of the gas-filled detectors based on the GEM and TGEM technologies have been studied in the multistage gas amplification circuit with the aim of selecting variants for tracking detectors of the muon system capable of operating at high counting rates in the CBM experiment. Two- and three-component mixtures based on Ar and He are used as the working gas. Their key characteristics are presented. The gas amplification factors are measured for various high-voltage modes. The charge collection times determining the response speed of the tested detectors are estimated.

Micromegas detectors for the Muon Spectrometer upgrade of the ATLAS experiment

Through the years the Micromegas (MICRO MEsh GAseous Structure) devices have proven to be reliable detectors with excellent space resolution and high rate capability. Large area Micromegas will be employed for the first time in high-energy physics for the Muon Spectrometer upgrade of the ATLAS experiment at the CERN LHC. A total surface of about 150 m2 of the forward regions of the Muon Spectrometer will be equipped with 8 layers of Micromegas modules. Each module covers a surface from 2 to 3 m2 for a total active area of 1200 m2. Together with the small-strips Thin Gap Chambers, they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS Endcap Muon tracking system in the 2018/19 shutdown. The breakthroughs and developments of this type of Micro Pattern Gas Detector will be reviewed, along with the path towards the construction of the modules, which will take place in several production sites starting in 2015. An overview of the detector performance obtained in the test beam campaigns in recent years at CERN will be also presented.

Development of a High-Resolution Muon Tracking System Based on Micropattern Detectors

A muon tracking system consisting of four 9cm x 10cm sized bulk Micromegas detectors with 128um amplification-gap and two 10cm x 10cm triple GEM detectors is foreseen for high-precision tracking of 140GeV muons at the H8 beamline at CERN with a rate of up to 10kHz and an overall resolution below 40um. Larger detectors with an active area of 0.5m^2 and more are under development for detector studies in high neutron or gamma ray background environments at the Gamma Irradiation Facility at CERN and the Munich tandem accelerator. Signal studies of both detector types have been performed by recording cosmic muon and 5.9keV X-ray signals with a single charge-sensitive preamplifier using several gas-mixtures of Ar:CO_2. The signals were digitized using 1GHz VME based flashADCs with 2520 sampling points. The analysis of the complete signal-cycles allows for the determination of rise times, pulse heights, timing fluctuations and discrimination of background, resulting in a FWHM energy resolution of about 20% and detection efficiencies of 99% and more. Models for signal formation in both detector types will be presented. The single detector spatial resolution of 80um was measured using a fast Gassiplex based strip readout with readout strips of 150um width and a pitch of 250um. The Gassiplex readout, formerly used at the HERMES experiment, had to be substantially adapted. No more crosstalk or non-linearities were observed after reconfiguration of the multiplexing amplifier on the frontend boards. The observed spatial resolution is limited by multiple scattering of the cosmic muons used in the laboratory. We also report on the sensitivity to gamma- and neutron background and on the behaviour of spatial resolution as a function of background rates.

Portable cosmic muon telescope for environmental applications

A portable, low power consumption cosmic muon tracking system based on Close Cathode MWPC technology is presented, which is designed for operation in highly humid environmental conditions such as underground caves, tunnels, or cellars. The system measures the angular distribution of cosmic muons with resolution of 10mrad, allowing for a tomographic mapping of the soil density above the detector unit. The size of the detector, 0.1m2 of total sensitive surface, was designed to fulfill the requirement of transport through humanly passable natural cave tunnels. First results from the Ariadne Cave System in Pilis Mountains, Hungary are shown, which constrains the necessary data taking time for meaningful tomographic mapping.

Calibration of muon reconstruction algorithms using an external muon tracking system at the Sudbury Neutrino Observatory

To help constrain the algorithms used in reconstructing high-energy muon events incident on the Sudbury Neutrino Observatory (SNO), a muon tracking system was installed. The system consisted of four planes of wire chambers, which were triggered by scintillator panels. The system was integrated with SNO's main data acquisition system and took data for a total of 95 live days. Using cosmic-ray events reconstructed in both the wire chambers and in SNO's water Cherenkov detector, the external muon tracking system was able to constrain the uncertainty on the muon direction to better than 0.6°.

Readout system of the ALICE Muon tracking detector

A Large Ion Collider Experiment (ALICE) will be aimed at studying heavy ion collisions at the extreme energy densities accessible at the CERN's Large Hadron Collider (LHC), where the formation of the Quark Gluon Plasma is expected. The ALICE muon forward spectrometer will identify muons with momentum above 4GeV/c, allowing the study of quarkonia and heavy flavors in the pseudorapidity range −4.0<η<−2.5 with 2π azimuthal coverage. The muon tracking system consists of 10 Cathode Pad Chambers (CPC) with 1.1 million of pads that represent the total number of acquisition channels to manage.In this article, we will give an overview of the ALICE Muon Spectrometer. Afterward, we will focus on tracking system Front end Electronics (FEE) and readout system. We will show that the Digital Signal Processor (DSP) architecture fulfills all the requirements, including radiation hardness against neutrons. Finally, real-time performances are discussed.