Muon Detector Research Articles

Observation of Gamma Rays up to 320 TeV from the Middle-aged TeV Pulsar Wind Nebula HESS J1849−000

Gamma rays from HESS J1849−000, a middle-aged TeV pulsar wind nebula (PWN), are observed by the Tibet air shower array and the muon detector array. The detection significance of gamma rays reaches 4.0σ and 4.4σ levels above 25 TeV and 100 TeV, respectively, in units of the Gaussian standard deviation σ. The energy spectrum measured between 40 TeV < E < 320 TeV for the first time is described with a simple power-law function of . The gamma-ray energy spectrum from the sub-TeV (E < 1 TeV) to sub-PeV (100 TeV < E < 1 PeV) ranges, including the results of previous studies, can be modeled with the leptonic scenario, i.e., inverse Compton scattering by high-energy electrons accelerated by the PWN of PSR J1849−0001. On the other hand, the gamma-ray energy spectrum can also be modeled with the hadronic scenario in which gamma rays are generated from the decay of neutral pions produced by collisions between accelerated cosmic-ray protons and the ambient molecular cloud found in the gamma-ray-emitting region. The cutoff energy of cosmic-ray protons E p,cut is estimated as , suggesting that protons are accelerated up to the PeV energy range. Our study thus proposes that HESS J1849−000 should be further investigated as a new candidate as a Galactic PeV cosmic-ray accelerator, or “PeVatron.”

Conceptual Design of CEPC Detector Magnet

The Circular Electron Positron Collider (CEPC) will measure the Higgs boson properties in great detail. The detector needs a 3 Tesla superconducting solenoid followed by a muon detector embedded in a flux return yoke. This paper introduces the conceptual design of the superconducting solenoid includes two schemes based on LTS and HTS technology. The fundamental parameters and structures of magnets are discussed, and the advancements in electromagnetic design, quench calculation, cryogenic system design, and conductor development are outlined. The conductors used in the two schemes, the aluminum stabilized NbTi/Cu Rutherford cable and the Aluminum stabilized Stacked REBCO Tape Cable (ASTC), are also under development. The viability of the first-ever HTS aluminum stabilized cable proposal is confirmed, and the technology of co-extrusion aluminum coating has been preliminary mastered.

Fast kernel methods for data quality monitoring as a goodness-of-fit test

We propose an accurate and efficient machine learning approach for monitoring particle detectors in real-time. The goal is to assess the compatibility of incoming experimental data with a reference dataset, characterising the data behaviour under normal circumstances, via a likelihood-ratio hypothesis test. The model is based on a modern implementation of kernel methods, nonparametric algorithms that can learn any continuous function given enough data. The resulting approach is efficient and agnostic to the type of anomaly that may be present in the data. Our study demonstrates the effectiveness of this strategy on multivariate data from drift tube chamber muon detectors.

The JUNO water Cherenkov detector system

The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton liquid scintillator detector with the primary physics goal of the neutrino mass ordering determination. The detector will be built in a laboratory 650-m underground. The pool is filled with 34 kton ultrapure water outside the central detector as a water Cherenkov detector for cosmic muon detection. 2400 MCP-PMTs detect the water Cherenkov light produced by cosmic muons. The inner surface of the water veto is covered with a Tyvek reflector to increase the light collection efficiency. A water system is used for water purification and circulation to maintain high water quality for optimal detector performance. A set of radon removal equipment will be integrated with the water system to reduce the radon-induced background in the central detector. Based on prototype studies, the radon concentration in water could be reduced to less than 10 mBq/m3. The cosmic muon detection efficiency of the water Cherenkov detector can reach 99.5%. With this veto system, the cosmic muon-induced fast neutron background can also be reduced to the level of about ∼0.1/day level.

Cosmic Ray Detector Using Geiger Tubes and Coincident Pulses

Cosmic Rays (CRs) are extreme strength particles resigning from outside the Earth and transported through space. These atoms can considerably impact human fitness, aviation and photo electric suppliers. A high energy radiation from space indicator is a tool that detects and measures the force of limitless beams. In this project, one can build a high energy radiation from space indicator utilizing two Geiger Muller tubes, Lead sheets, a stiff frame, a Microcontroller and a Protractor to regulate the frame at certain angle. At different altitudes, at different temperatures, at different humidities, we can identify and record CRs. A portable Muon Detector project that incorporates two Geiger Tubes enclosed within a lead sheet for detecting CRs. The system utilizes a coincidence circuit login to enhance the detection accuracy and reduce false positive rates. Additionally, the device is equipped with sensors to collect data on Temperature, Humidity, Latitude, Longitude and Atmospheric Pressure. The combination of these features provides a comprehensive and versatile solution for studying Muons and their interactions with the surrounding environment.

DIMUS: super-compact Dimuonium Spectroscopy collider at Fermilab

While dimuonium (μ + μ -) — the “smallest QED atom” — has not yet been observed, it is of utmost fundamental interest. By virtue of the larger mass, dimuonium has greater sensitivity to beyond the standard model (BSM) effects than its cousins positronium or muonium, both discovered long ago, while not suffering from large QCD uncertainties. Dimuonium atoms can be created in e + e - collisions with large longitudinal momentum, allowing them to decay a small distance away from the beam crossing point and avoid prompt backgrounds. We envision a unique cost-effective and fast-timeline opportunity for copious production of (μ + μ -) atoms at the production threshold via a modest modification of existing Fermilab Accelerator Science and Technology (FAST) facility to arrange collisions of 408 MeV electrons and positrons at a 75° angle. This compact 23 m circumference collider (DIMUS) will allow for precision tests of QED and open the door for searches for new physics coupled to the muon. The FAST facility is perfectly suited for DIMUS as there are existing SRF accelerators and infrastructure, capable of producing high energy, high current electron and positron beams, sufficient for O(1032)cm2 s-1 luminosity and ∼0.5 million dimuons per year. The expansion will require installation of a second SRF cryomodule, positron production and accumulation system, fast injection/extraction kickers and two small circumference intersecting rings. An approximately meter-sized detector with several layers of modern pixelated silicon detector and crystal-based electromagnetic calorimeters will ensure observation of the decays of dimuonium to electron-positron pairs in presence of the Bhabba scattering background. An expansion of the system to include solenoidal magnet outside of the calorimeter system, a layer of steel shielding behind the magnet, and a set of dedicated muon detectors would extend the physics program of DIMUS to include precision studies of rare processes with muons, pions, and η mesons produced in e + e - collisions.

Development of a precise time and position resolution TOF-tracker MRPC for the [formula omitted]20 beam line at J-PARC

We are developing time-of-flight (TOF) multi-gap Resistive Plate Chambers (MRPCs) which perform both timing and hit position measurements, the TOF-tracker MRPC, for muon detection to measure exclusive Drell–Yan reaction (π−p→γ∗n→μ+μ−n) at J-PARC’s hadron hall. Here we report on the development of a prototype TOF-tracker MRPC with a sensitive area of 500×1000mm2 and its performance in an electron-positron particle beam at the SPring-8 synchrotron in Japan.

Observation of Collider Muon Neutrinos with the SND@LHC Experiment.

We report the direct observation of muon neutrino interactions with the SND@LHC detector at the Large Hadron Collider. A dataset of proton-proton collisions at sqrt[s]=13.6 TeV collected by SND@LHC in 2022 is used, corresponding to an integrated luminosity of 36.8 fb^{-1}. The search is based on information from the active electronic components of the SND@LHC detector, which covers the pseudorapidity region of 7.2<η<8.4, inaccessible to the other experiments at the collider. Muon neutrino candidates are identified through their charged-current interaction topology, with a track propagating through the entire length of the muon detector. After selection cuts, 8 ν_{μ} interaction candidate events remain with an estimated background of 0.086 events, yielding a significance of about 7 standard deviations for the observed ν_{μ} signal.

High-resolution structural imaging of volcanoes using improved muon tracking

SUMMARY Muography is increasingly used to image the density distribution of volcanic edifices, complementing traditional geophysical tomographies. Here, we present a new muon data processing algorithm, and apply it to a new generation of scintillator-based muon detectors, to image the relative density distribution in La Soufrière de Guadeloupe volcano (Lesser Antilles, France). Our processing method iteratively searches for the best fit of each muon trajectory, accounting for all the hits registered by the detector related to the particular muon event. We test the performance of our algorithm numerically, simulating the interaction of muons with our detector and accounting for its exact assemblage including the scintillator bars and lead shielding. We find that our new data processing mitigates the impact of spurious signals coming from secondary particles, and improves the amount of successfully reconstructed events. The resulting 2-D muon images at La Soufrière have higher angular resolution than previous ones and capture the heterogeneous structure of the dome. They show density anomalies located on the summit southern region, which includes a boiling acid lake and degassing fractures, where the rock is the most porous and fumarolic activity is ongoing. This work shows the importance of combining numerical simulations of muon propagation with precise raw data processing to obtain high-quality results. It is also a first step towards fully assessing the noise contamination sources when performing muon tomography, and their correction, prior to geophysical interpretations.

Space weather monitoring with Health Canada’s terrestrial radiation monitoring network

This work presents a feasibility study of utilizing Health Canada’s terrestrial radiation monitoring network, the Fixed Point Surveillance (FPS) network, for space weather monitoring through demonstrating detections of Forbush decrease and ground level enhancement events. The network is currently comprised of more than eighty sodium iodide spectrometers distributed across Canada. It was designed for terrestrial radiation monitoring but is also capable of registering cosmic radiation in a high-energy channel. Data from fourteen FPS stations for the period from 2003 to 2018 were analyzed and compared with data obtained by other ground-level cosmic radiation monitoring systems. The level of atmospheric impacts on measurements can be well explained, and signatures of both long-term solar cycle variations and sporadic solar events have been detected in the FPS network. The Forbush decrease amplitudes in FPS were found to be comparable to those obtained in the global muon detector network but about 2–3 times lower than those recorded by the global neutron monitoring network. This study suggests that the 20 years of cosmic ray data from the FPS network can be used for climatological space weather studies. In addition, the network can be readily available for real-time space weather monitoring.

Machine Learning based tool for CMS RPC currents quality monitoring

The muon system of the CERN Compact Muon Solenoid (CMS) experiment includes more than a thousand Resistive Plate Chambers (RPC). They are gaseous detectors operated in the hostile environment of the CMS underground cavern on the Large Hadron Collider where pp luminosities of up to 2×1034cm−2s−1 are routinely achieved. The CMS RPC system performance is constantly monitored and the detector is regularly maintained to ensure stable operation. The main monitorable characteristics are dark current, efficiency for muon detection, noise rate etc. Herein we describe an automated tool for CMS RPC current monitoring which uses Machine Learning techniques. We further elaborate on the dedicated generalized linear model proposed already and add autoencoder models for self-consistent predictions as well as hybrid models to allow for RPC current predictions in a distant future.

Development and performance studies of a real size Resistive Plate Chamber tested at GIF＋＋, CERN for CBM-MuCh at FAIR, Germany

In the year 2016, Resistive Plate Chambers (RPCs) were proposed to be used as muon detectors in the 3rd and 4th stations of the Muon Chamber (MuCh) detector set-up of the under construction Compressed Baryonic Matter (CBM) experiment at the Facility for Anti-proton and Ion Research (FAIR) in Darmstadt, Germany. Since then, sincere efforts are being given to develop suitable detectors for this purpose with major challenges being the capability to handle high particle rates and perform well under harsh radiation environments. We have developed and tested a real size RPC along with its dedicated PCB and electronics read-out chain in GIF＋＋ under intense photon flux for its muon detection capability. In this manuscript, we have presented the test results of the RPC tested during November-2021 beam time in GIF＋＋, CERN, Switzerland.

Muon radiography experiments on the subway overburden structure detection

Muon radiography is an innovative and non-destructive technique for internal density structure imaging, based on measuring the attenuation of cosmic-ray muons after they penetrate the target. Due to the strong penetration ability of muons, the detection range of muon radiography can reach the order of hundreds of meters or even kilometers. Using a portable muon detector composed of plastic scintillators and silicon photomultipliers, we performed a short-duration (1 h) flux scanning experiment of the overburden above the platform and tunnel of the Xiaoying West Road subway station under construction. With the observation direction facing up, the detector is placed on the north side of the track and moved eastward from the platform section inside the station to the tunnel section. The scanning length is 264 m and a total of 21 locations are observed. By comparing the observed and predicted values of the muon survival ratio at different locations, the experiment accurately detects the jump in thickness at the interface of the platform section and tunnel section. Furthermore, unknown anomalies caused by randomly placed piles of lightweight bricks and a side passage mouth above the observation locations are detected and confirmed later. This experiment verifies the feasibility of using natural muons to quickly detect abnormal structures of the overburden of tunnel, and shows that muon radiography has broad application prospects in tunnel safety and other similar aspects.

Commissioning and Operation of the Upgraded Belle II DAQ System With PCI-Express-Based High-Speed Readout

The Belle II experiment and the SuperKEKB collider are designed to operate under a higher luminosity compared to that of Belle for the improvement on rare <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</i> meson decay study and new physics search. In order to break the bottleneck of bandwidth and to improve the stability in the operation of the Belle II Data Acquisition (DAQ) system, a new PCI-Express-based readout system has been developed. The new system includes a PCI-Express-based high-speed readout board (PCIe40), which was originally developed for the upgrades of the LHCb and ALICE experiments, the PCIe40 firmware, the slow control and readout software running on a readout PC. The new readout system’s commissioning with most of the Belle II sub-detectors has been performed, and the readout upgrade is complete for the particle-identification detectors and the neutral kaon and muon detector in Belle II, which has been operating stably with the new system in the beam collision “Physics runs”. The results of the commissioning and the performance of the global DAQ operation will be reported.

MRNG: Accessing Cosmic Radiation as an Entropy Source for a Non-Deterministic Random Number Generator.

Privacy and security require not only strong algorithms but also reliable and readily available sources of randomness. To tackle this problem, one of the causes of single-event upsets is the utilization of a non-deterministic entropy source, specifically ultra-high energy cosmic rays. An adapted prototype based on existing muon detection technology was used as the methodology during the experiment and tested for its statistical strength. Our results show that the random bit sequence extracted from the detections successfully passed established randomness tests. The detections correspond to cosmic rays recorded using a common smartphone during our experiment. Despite the limited sample, our work provides valuable insights into the use of ultra-high energy cosmic rays as an entropy source.

Invisible Higgs boson decay from forward muons at a muon collider

We propose to probe the Higgs boson decay to invisible particles at a muon collider by observing the forward muons that are produced in association with the Higgs in the $Z$-boson fusion channel. An excellent sensitivity is possible in line of principle, owing to the large number of produced Higgs bosons, provided a forward muon detector is installed. We find that the resolution on the measurement of the muon energy and angle will be the main factor limiting the actual sensitivity. This poses tight requirements on the forward muon detector design.

Research about how lead influence the detection rate of muons and its attenuation coefficient

This paper presents a way to determine how lead influence the detection rate of muon at the earths surface. There are four sets of data on different thicknesses of lead above the detectors included in the experiments, and the largest set has 45054 groups of data. After using python modules to analyze the data of muons and other background particles such as electrons detected by desktop muon detectors, the discussion about identity of muons, especially about the detection rate, was conducted, as well as their relations with other factors. Then, the comparison was made between the average rate of muon detections of varied thicknesses of lead above the detectors to define the correlation between them. The result of data analysis mainly demonstrates an exponentially decreasing relationship. Accordingly, the calculation of the attenuation coefficient of lead which influences the exponential relationship was conducted as well.

Content of Muons in Extensive Air Showers Measured by Yakutsk Array

Lateral distribution of muons in extensive air showers registered at the Yakutsk array was investigated. The analysis covers two periods of observation: before 2018 and after 2020, when the revision of muon detectors with 1-GeV threshold was complete. Measured values of muon density are compared to computational results obtained within the framework of two hadron interaction models. Within the energy domain above 1018 eV the best agreement is observed for proton composition primary cosmic rays.

Transmission-Based Muography for Ore Bodies Prospecting: A Case Study from a Skarn Complex in Italy

Transmission-based muography (TM) is an innovative imaging technique based on the measurement and analysis of the cosmic ray muons flux attenuation within the target under investigation. This technique allows imaging inner-body density differences and has successfully been applied in a wide range of research fields: geology, archaeology, engineering geology and civil engineering. The aim of this study is to show the reliability of TM as an innovative, noninvasive geophysical method for ore body prospecting and other mining related studies. The measurements were carried out at the Temperino mine in the San Silvestro Archaeological and Mining Park (Campiglia Marittima, Italy), where several magmatic and metasomatic geological units are embodied. Among them, a Cu–Fe–Zn–Pb(–Ag) sulfide skarn complex primarily composed by hedenbergite and ilvaite minerals. Using the acquired muon imaging data obtained with the MIMA (Muon Imaging for Mining and Archaeology) detector prototype (cubic detector of 0.5 × 0.5 × 0.5 m3), the presence of a high-density vein inside the skarn body within the rock volume above the muon detector was identified, localized and interpreted. Applying a back-projection algorithm to the obtained 2D transmission map made it possible to estimate and visualize as point cloud data, in a 2D or 3D environment, the identified high-density body and its relative distance from the detector. The results of this study highlight the potential of muography as a support tool to other geophysical methods in the field of mining exploration.

RPC background studies at CMS experiment

During Run2 the high instantaneous luminosity, up to 2.21034cm−2s−1, lead to a substantial hit rate in the Compact Muon Solenoid experiment’s muon chambers due to multiple background sources to physics processes sought for at LHC. In this article we will describe the analysis method devised to measure and identify the contributions to such background in the Resistive Plate Chambers. Thorough understanding of the background rates provides the base for the upgrade of the muon detectors for the High-Luminosity LHC.