Muon Detector Research Articles

Overview of the PANDA detector design at FAIR

PANDA (antiProton ANihilation at DArmstadt) is the central experiment to fully exploit the physics research potential of antiproton beams at the international accelerator Facility for Antiproton and Ion Research in Europe (FAIR), currently under construction at GSI. Phase-space cooled high intensity antiproton beams up to 15 GeV/c will be provided by the High Energy Storage Ring (HESR) at FAIR to interact with PANDA internal proton or nuclear targets enabling a broad range of exciting studies in Particle and Nuclear Physics. The PANDA detector features two spectrometers, the Target Spectrometer with a superconducting solenoid magnet of 2 T around the interaction region with hermetic coverage and the Forward Spectrometer with a 2 Tm dipole magnet for coverage of the forward boosted particles. Several modern particle detector systems are employed in PANDA to provide excellent charged particle tracking, particle identification, calorimetry and muon detection, over the full momentum range in both spectrometers throughout the lifetime of the experiment. Focusing on the various PANDA detector systems we present an overview of recent developments, the detector construction progress and conclude with an outline for a phased deployment of PANDA at FAIR.

Status of the COMET experiment

The COMET (COherent Muon to Electron Transition) experiment, currently being built in Tokai, Japan, will search for the coherent neutrinoless transition of muons to electrons in the coulomb field of atomic nuclei. The process is highly suppressed in the Standard Model and therefore provides a promising channel to probe new physics. The experiment will be carried out in a staged approach. Phase-I of COMET aims to search for the process with a single event sensitivity of 𝒪(10−15). Additionally, precise measurements of muon beam dynamics and detector prototyping for Phase-II will be conducted. Utilizing a much higher intensity proton beam, a more complex and longer muon/electron transport system, and gained experience from Phase-I, an improvement of at least four orders of magnitude over the current best branching ratio limit up to 𝒪(10−17) is envisioned for Phase-II. This article will give a status report for Phase-I of COMET.

Muon counting with the Underground Muon Detector of The Pierre Auger Observatory

The Underground Muon Detector (UMD) aims to extend the detection range of the Pierre Auger Observatory to observe cosmic rays of energies greater than 1016.6 eV and performs a direct measurement of the muon component (sensitive observable to the mass composition) of the air showers. In this work, we will present an overview of the final design of the UMD and its reconstruction techniques alongside the observations obtained during the engineering array phase. First results suggest that the current hadronic interaction models have a muon deficit at energies between 2×1017 eV and 2×1018 eV.

Understanding the Phase Reversals of Galactic Cosmic-Ray Anisotropies

Energy spectra and anisotropies are very important probes of the origin of cosmic rays. Recent measurements show that complicated but very interesting structures exist at similar energies in both the spectra and energy-dependent anisotropies, indicating a common origin of these structures. A particularly interesting phenomenon is that there is a reversal of the phase of the dipole anisotropies, which challenges theoretical modeling. In this work, for the first time, we identify that there might be an additional phase reversal at ∼100 GeV energies of the dipole anisotropies as indicated by a few underground muon detectors and the first direct measurement by the Fermi satellite, coincident with the hundreds of GV hardening of the spectra. We propose that these two phase reversals, together with the energy evolution of the amplitudes and spectra, can be naturally explained with a nearby source overlapping onto the diffuse background. As a consequence, the spectra and anisotropies can be understood as the scalar and vector components of this model, and the two reversals of the phases characterize just the competition of the cosmic-ray streamings between the nearby source and the background. The alignment of the cosmic-ray streamings along the local large-scale magnetic field may play an important but subdominant role in regulating the cosmic-ray propagation. More precise measurements of the anisotropy evolution at both low energies by space detectors and high energies by air shower experiments for individual species will be essential to further test this scenario.

The [formula omitted]-RWELL technology for the preshower and muon detectors of the IDEA detector

The IDEA detector concept has been designed to operate at a future large circular e+e− collider, like FCC-ee or CEPC. The IDEA detector has an innovative design with a central tracker enclosed in a superconducting solenoidal magnet. Going outwards, a preshower system followed by a dual readout calorimeter is foreseen. In the iron yoke, that closes the magnetic field, are then located three stations of muon detectors. The preshower and muon detectors are based on the μ-RWELL technology that inherits the best characteristics of the GEM, in particular the layout of the amplification stage, and Micromega detectors, that inspired the presence of a resistive stage. To profit of the industrial production capabilities of this technology, a modular design has been adopted for both systems: the μ-RWELL tile will have an active area of 50 × 50 cm2, but with a pitch between the readout strips of 400μm for the preshower and about 1 mm for the muon system. Other requirements are: a spatial resolution of the order of 100μm for the preshower and a reasonable total number of front-end channels for the muon system. To optimize the resistivity and the strip pitch, we have built a set of prototypes with active area of 5 × 40 cm2 and 40 cm long strips. The DLC resistivity is ranging from 10 to 80 MΩ/□. All these detectors have been exposed in October 2021 to a muon beam at the CERN SPS. The very positive results obtained pave the way for a completely new and competitive MPGD tracking device for high energy physics experiments.

Self-calibration of LHAASO-KM2A electromagnetic particle detectors using single particles within extensive air showers

In the Large High Altitude Air Shower Observatory (LHAASO), the square kilometer array, with 5249 electromagnetic particle detectors (EDs) and 1188 muon detectors, is deployed to explore the gamma-ray sources above 30 TeV with unprecedented sensitivity and to measure primary cosmic rays in the energy range from 10 TeV to 100 PeV. The energetic particles produced by extensive air showers can serve as a continuously available source for calibration of the numerous EDs over a large area. In this study, the detector untriggered probability is first proposed to estimate the particle density at different distances from the shower core and distinguish the characteristic single-particle signal detected by each ED. This method uses science data directly, and does not require prior knowledge of the cosmic-ray elemental composition or hadronic interaction model. Experimental results show that this self-calibration can be used to determine the number of particles detected by each ED with an accuracy better than 2% within a time scale of hours, which is adequate to meet the physics requirements of the LHAASO experiment. With this high efficiency and accuracy, this calibration also provides an ideal method to monitor the detector performance throughout an expected lifetime of >10 years.9 MoreReceived 15 April 2022Accepted 21 November 2022DOI:https://doi.org/10.1103/PhysRevD.106.122004© 2022 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasCosmic rays & astroparticlesTechniquesAstrophysical & cosmological simulationsCosmic ray & astroparticle detectorsMonte Carlo methodsProbability theoryScintillatorsAccelerators & BeamsGravitation, Cosmology & AstrophysicsParticles & Fields

Model-independent study on the anomalous $$ZZ\gamma $$ and $$Z\gamma \gamma $$ couplings at the future muon collider

In this study, we investigate the potential of $$\mu ^{-} \mu ^{+}\rightarrow Z\gamma \rightarrow \nu \bar{\nu }\gamma $$ process at the future muon collider with a center-of-mass energy of 3 TeV to examine the anomalous ZZ $$\gamma $$ and $$Z\gamma \gamma $$ neutral triple gauge couplings defining CP-conserving $$C_{\widetilde{B}W}/{\Lambda ^4}$$ coupling and three CP-violating $$C_{\mathrm{BB}}/{\Lambda ^4}$$ , $$C_{\mathrm{BW}}/{\Lambda ^4}$$ , $$C_{\mathrm{WW}}/{\Lambda ^4}$$ couplings. All signal and relevant background events are generated in MadGraph and passed through Pythia for parton showering and hadronization. Detector effects are also considered via tuned muon detector cards in Delphes. The effects of systematic uncertainties of $$0\%$$ , $$3\%$$ and $$5\%$$ on the sensitivities are studied. The best sensitivities obtained from the process $$\mu ^{-} \mu ^{+}\rightarrow Z\gamma \rightarrow \nu \bar{\nu }\gamma $$ are $$[-6.53;6.64]\times 10^{-2}$$ TeV $$^{-4}$$ on CP-conserving $$C_{\widetilde{B}W}/{\Lambda ^4}$$ coupling and $$[-2.47;2.47]\times 10^{-2}$$ TeV $$^{-4}$$ , $$[-8.46;8.46]\times 10^{-2}$$ TeV $$^{-4}$$ and $$[-2.20;2.20]\times 10^{-1}$$ TeV $$^{-4}$$ on CP-conserving $$C_{\mathrm{BB}}/{\Lambda ^4}$$ , $$C_{\mathrm{BW}}/{\Lambda ^4}$$ , $$C_{\mathrm{WW}}/{\Lambda ^4}$$ couplings , respectively. Our obtained results on the anomalous neutral gauge couplings set more stringent sensitivity, ranging between 5 and 15 times than the current experimental results while slightly better than the phenomenological studies at future pp colliders such as the HL-LHC, the HE-LHC and the FCC-hh, respectively. On the other hand, we can see that the bounds on the anomalous neutral gauge couplings expected to be obtained for the future $$e^{-}e^{+}$$ colliders such as the CLIC are roughly 2 times better than our results.

Muon rate measurement under different thicknesses of Pb

The major purpose of this paper is to analyze the rate of events under the different thicknesses of Pb on the top of two cosmic watch desktop muon detectors. The desktop muon detector is a simple, easy-built, and cheap cosmic ray muon detector. Using these detectors, the researchers experimented with different altitudes [2]. In this work, we concluded how the thickness of Pb above the detectors influences the rate of the muon. We placed one-on-top of another detector and changed the thickness of Pb above them. Using the python program, we analyzed a large number of data collected by the two desktop muon detectors systematically. We analyzed the relationship between the muon rate with the thickness and calculated the parameters. The result shows muon rate decreases exponentially as thickness increasing.

Development of a muon detector based on a plastic scintillator and WLS fibers to be used for muon tomography system

Muon tomography is a useful method for monitoring special nuclear materials (SNMs) such as spent nuclear fuel inside dry cask storage. Multiple Coulomb scattering of muons can be used to provide information about the 3-dimensional structure and atomic number(Z) of the inner materials. Tomography using muons is less affected by the shielding material and less harmful to health than other measurement methods.We developed a muon detector for muon tomography, which consists of a plastic scintillator, 64 long wavelength-shifting (WLS) fibers attached to the top of the plastic scintillator, and silicon photomultipliers (SiPMs) connected to both ends of each WLS fiber. The muon detector can acquire X and Y positions simultaneously using a position determination algorithm.The design parameters of the muon detector were optimized using DETECT2000 and Geant4 simulations, and a muon detector prototype was built based on the results. Spatial resolution measurement was performed using simulations and experiments to evaluate the feasibility of the muon detector. The experimental results were in good agreement with the simulation results. The muon detector has been confirmed for use in a muon tomography system.

RPCs for the SND Muon System of the SHiP experiment

SHiP (Search for Hidden Particles) is a proposed beam dump experiment at CERN SPS, with the aim of exploring the so-called Hidden Sector. Since a large neutrino flux is expected to be produced at the beam dump, the experiment could also allow for the study of neutrino physics with unprecedented statistics. A dedicated Scattering and Neutrino Detector (SND), equipped with a downstream Muon Identification System, is thus being designed. The SND muon detector consists of iron filters interleaved with tracking planes, based on RPC technology. Each muon plane has an active area of about (2 x 4) m2 and consists of three large gaps read out by two panels of perpendicular strips. The SHiP RPCs have to provide a uniform spatial response as well as high efficiency. The design of the SND muon system is presented and the performance of a SHiP RPC prototype is discussed.

The Detector Control System of the New Small Wheel Electronics for the ATLAS experiment

The present ATLAS Small Wheel Muon detector is be replaced with a New Small Wheel(NSW) detector in order to cope up with the future LHC runs of high luminosit. One crucial part of the integration procedure concerns the validation of the electronics for a system with more than 2.1 M electronic channels. The readout chain is based on optical link technology connecting the back-end to the front-end electronics via the FELIX, which is a newly developed system that serves as the next generation readout driver for ATLAS. For the configuration, calibration and monitoring path the various electronics boards are supplied with the GBT-SCA ASIC and its purpose is to distribute control and monitoring signals to the electronics. Due to its complexity, NSW electronics requires the development of a sophisticated Control System. The use of such a system is necessary to allow the electronics to function consistently, safely and as a seamless interface to all sub-detectors and the technical infrastructure of the experiment. The central system handles the transition between the probe’s possible operating states while ensuring continuous monitoring and archiving of the system’s operating parameters.

GEM Detectors for the Upgrade of the CMS Muon Spectrometer

The Large Hadron Collider (LHC) will be upgraded in several phases to allow a significant expansion of its physics program. We are nearing the end of Long Shutdown 2 (LS2, 2019-2021), after which the LHC will initiate its third running period (Run-3) expected to last three years. In Run-3 LHC will collide protons with an instantaneous luminosity of 2-3×1034cm−2s−1 exceeding its design luminosity by a factor of 2-3, allowing the CMS experiment to collect an integrated luminosity of approximately 100 fb−1/year. A subsequent upgrade in 2025-27 (Long Shutdown 3 - LS3) will increase the luminosity up to 5×1034cm−2s−1. The CMS muon system must enable a physics program that maintains sensitivity for electroweak measurements and for Beyond the Standard Model searches, similar to what was achieved in Run-1 and Run-2. To cope with the corresponding increase in trigger rates and to provide additional coordinate measurements in the high background environment, the installation of additional sets of muon detectors, referred to as GE1/1, GE2/1 and ME0, that use Gas Electron Multiplier (GEM) technology, has been approved. The GE1/1 chambers have already been installed in spring-summer 2020 and are currently being commissioned and tested with cosmic rays. The construction of GE2/1 will start in 2021, while for ME0 the final R&D is in progress and construction is foreseen in 2023. We present an overview of the Muon Spectrometer upgrade using the GEM technology, the performance of the GE1/1 chambers during Quality Control tests and in cosmic ray tests, and the design of the GE2/1 and ME0 chambers.

Status of the AugerPrime upgrade of the Pierre Auger Observatory

The Pierre Auger Observatory consists of a detector system to study ultrahigh-energy cosmic rays. These cosmic rays can be detected only through the observation of extensive air showers. The hybrid detection of air showers at the Observatory is based on the Surface Detector (SD) – an array of about 1660 water-Cherenkov detectors, and the Fluorescence Detector, with 27 telescopes overlooking the SD. Recently, an upgrade of the Observatory was initiated, called AugerPrime. The main purpose of the upgrade is to improve the mass composition sensitivity of the SD through precise measurements of the muonic and electromagnetic components of extensive air showers. For this purpose, additional scintillator and radio detectors are being installed on top of SD stations. The upgrade also includes updated SD electronics, and underground muon detectors. In this talk, the motivation and the current status of the upgrade will be reviewed.

Improved Resistive Plate Chambers for the upgrade of the CMS muon detector

Several upgrades of the Resistive Plate Chamber (RPC) system of the Compact Muon Solenoid (CMS) experiment are currently being implemented to ensure a highly performing muon system during the upcoming High Luminosity phase of the Large Hadron Collider which will have an increased integrated luminosity of 3000 fb−1. The expected experimental conditions in that period present a challenge for the entire CMS detection system. To extend the RPC coverage, an improved version of the already existing RPCs will be installed in the forward region of the 3rd and 4th endcap disks. The current overall status of this CMS RPC upgrade project is presented.

Characterisation of Hamamatsu SiPM for cosmic muon veto detector at IICHEP

A test setup is built to characterise the SiPM and to measure muon detection efficiency of an extruded plastic scintillator detector. In the setup, light from the scintillator is readout by SiPMs using two embedded Wavelength Shifting Fibres (WLS) fibres. The SiPM was calibrated using LED source, but alternate calibration procedures using radio-active source as well as noise data were also established. The SiPM is studied at various over voltages (V ov ) and determined the operating V ov by optimising the muon detection efficiency and noise rate. The muon position along the length of the scintillator is measured using timing information from both sides of the fibres. Results from our characterisation studies of SiPM (2mm × 2mm, Model S1330-2050VE), e.g. after pulse, cross-talk, recovery time etc. will be discussed in this paper.

The ATLAS ‘New Small Wheel’ Muon detector stations recently commissioned for LHC Run3

After nearly a decade of intense effort, the two New Small Wheels (NSW) for the upgrade of the ATLAS Muon spectrometer is now installed in the experiment and ready for final commissioning and to collect data in LHC Run3, starting March 2022. The NSW is the largest phase-1 upgrade project of ATLAS. It is challenging completion and readiness for data taking is a remarkable achievement of the collaboration. The two wheels (10 meters in diameter) replace the first Muon stations in the high-rapidity regions of ATLAS and are equipped with multiple layers of two completely new detector technologies: the small strips Thin Gap Chambers (sTGC) and the Micromegas (MM). The latter belongs to the family of Micro Pattern Gaseous Detectors (MPGD, for the first time used in such a large scale in HEP experiment). Each detector will cover more than 1200 m2 of the active area. The new system is required to maintain the present detector’s efficiency and momentum resolution level in the expected higher background level, given the ongoing LHC luminosity upgrades. In addition, it is necessary to keep an acceptable Muon trigger rate with the same Muon momentum threshold.11Copyright 2022 CERN for the benefit of the ATLAS muon collaboration. Reproduction of this article or parts of it is allowed as specified in the CC-BY-4.0 license.

Borehole cylindrical detector: A compact muon telescope for muon radiography applications

Muon Radiography (or muography) is a recent imaging methodology that uses cosmic muons to investigate the interior of large objects, such as volcanoes, mines or buildings. Some applications are intended to use muography to search for hidden cavities in the subsoil. In many cases the muon telescope needs to be installed underground, inside tunnels, excavated chambers or drilled holes. Usually places available to install the muon detector are difficult to access for people; we thus constructed a very compact cylindrical muon tracker to deal with this problem. Thanks to its shape the detector can be inserted in boreholes. It is 1 m high and has a 24 cm diameter; these dimensions are ideal to fit a realizable drilled well. It is composed of bar and arc-shaped plastic scintillators. The original geometry of sensitive elements allows to maximize the acceptance, minimizing the dead spaces. The new borehole cylindrical detector has been tested in laboratory and the result of a measurement of open sky muon flux is in good agreement with expectations. A first application on field is currently ongoing to validate the capability of the telescope to reveal the presence of underground voids.

Estimation of the number of counts on a particle counter detector with full time resolution

We present a general method for estimating the number of particles impinging on a segmented counter or, in general, on a counter with sub-units. We account for unresolved particles, i.e., the effect of two or more particles hitting the same sub-unit almost simultaneously. To achieve full time resolution we account for the dead time that occurs after the first time-bin of a particle signal. This general counting method can be applied to counting muons in existing detectors like the Underground Muon Detector of the Pierre Auger Observatory. We therefore use the latter as a study case to test the performance of our method and to compare it to other methods from literature. Our method proves to perform with little bias, and also provides an estimate of the number of particles as a function of time (as seen by the detector) to a single time-bin resolution. In this context, the new method can be useful for reconstructing parameters sensitive to cosmic ray mass, which are key to unveiling the origin of cosmic rays.

Status of the SABRE South experiment at the Stawell underground physics laboratory

The SABRE (Sodium iodide with Active Background REjection) experiments aim to detect an annual rate modulation from dark matter interactions in ultra-high purity NaI(Tl) crystals. The SABRE South experiment is located at the Stawell Underground Physics Laboratory (SUPL), Australia, and is the first deep underground laboratory in the Southern Hemisphere. SABRE South is designed to disentangle seasonal or site-related effects from the dark matter-like modulated signal first observed by DAMA/LIBRA in the Northern Hemisphere using an active veto and muon detection system. It is a partner to the SABRE North effort at the Laboratori Nazionali del Gran Sasso (LNGS). SABRE South is instrumented with ultra-high purity NaI(Tl) crystals immersed in a linear alkyl benzene (LAB) based liquid scintillator veto, further surrounded by passive steel and polyethylene shielding and a plastic scintillator muon veto. Significant work has been undertaken to understand the experimental backgrounds and performance of the crystals. The SABRE South experiment is under construction, and will be commissioned from late 2022 to early 2023. We will present the final design of SABRE South, the status of its construction, its expected background, and its sensitivity to a DAMA/LIBRA like modulation. We will also present recent quenching factor measurements of sodium nuclear recoils in NaI(Tl) crystals measured at the Heavy Ion Accelerator Facility, and a report on the status of SUPL.

Large-amplitude Bidirectional Anisotropy of Cosmic-Ray Intensity Observed with Worldwide Networks of Ground-based Neutron Monitors and Muon Detectors in 2021 November

We analyze the cosmic-ray variations during a significant Forbush decrease observed with worldwide networks of ground-based neutron monitors and muon detectors during 2021 November 3–5. Utilizing the difference between primary cosmic-ray rigidities monitored by neutron monitors and muon detectors, we deduce the rigidity spectra of the cosmic-ray density (or omnidirectional intensity) and the first- and second-order anisotropies separately for each hour of data. A clear two-step decrease is seen in the cosmic-ray density with the first ∼2% decrease after the interplanetary shock arrival followed by the second ∼5% decrease inside the magnetic flux rope (MFR) at 15 GV. Most strikingly, a large bidirectional streaming along the magnetic field is observed in the MFR with a peak amplitude of ∼5% at 15 GV, which is comparable to the total density decrease inside the MFR. The bidirectional streaming could be explained by adiabatic deceleration and/or focusing in the expanding MFR, which have stronger effects for pitch angles near 90°, or by selective entry of GCRs along a leg of the MFR. The peak anisotropy and density depression in the flux rope both decrease with increasing rigidity. The spectra vary dynamically, indicating that the temporal variations of density and anisotropy appear different in neutron monitor and muon detector data.