Cosmic Muon Data Research Articles

Simulation of RPC responses in mini-Iron Calorimeter for cosmic ray muon studies

A Prototype of the Iron Calorimeter for the India-based Neutrino Observatory is currently running in Madurai, India. This consists of twenty large area single gap Resistive Plate Chambers (RPCs) of size, ∼ 185 cm × 175 cm sandwiched between 11 layers of iron plates of thickness 5.6 cm. The total size of the mini-Iron Calorimeter(mini-ICAL) is 4 m × 4 m × 1.2 m and having a weight of 85 tons is a (1/600) scaled-down version of the ICAL detector of INO [1]. The detector is magnetized using iron plates and two sets of copper coils, each coil has 18 turns. The central region of the mini-ICAL, where the RPCs are placed, has a nearly uniform magnetic field of 1.4 T, similar to the magnetic field in the final ICAL detector. This prototype serves as the basis for the design of the demonstrators, which closely mimics the characteristics of a future ICAL. This detector is built to test the final electronics in the fringe field of the magnet and also to develop the experience to construct the ICAL detector. The mini-ICAL has been operational since 2018 and collects cosmic muon data with different configurations of RPC, and electronics, which are continuously changing for various R&D efforts. Dedicated efforts are made in parallel to measure the momentum and azimuthal angle of μ+ and μ- independently, which could be an important input to the cosmic neutrino event generators. To improve the precision of those measurements a dedicated simulation effort was made, particularly in the digitisation of the RPC signal for a real detector simulation, where efficiency, noise rate, strip multiplicity, etc. were matched with the real data collected during runs at mini-ICAL.

Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC

DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6 times 6 times 6 m^3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019–2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.

Energy and angular distributions of atmospheric muons at the Earth

A fair knowledge of the atmospheric muon distributions at Earth is a prerequisite for the simulations of cosmic ray setups and rare event search detectors. A modified power law is proposed for atmospheric muon energy distribution which gives a good description of the cosmic muon data in low as well as high energy regime. Using this distribution, analytical forms for zenith angle [Formula: see text] distribution are obtained. Assuming a flat Earth, it leads to the [Formula: see text] form where it is shown that the parameter [Formula: see text] is nothing but the power of the energy distribution. Exact analytical function is obtained for inclined trajectory of muon. A new closed form for zenith angle distribution is obtained without assuming a flat Earth and which gives an improved description of the data at all angles even above [Formula: see text]. These distributions are tested with the available atmospheric muon data of energy and angular distributions. The parameters of these distributions can be used to characterize the cosmic muon data as a function of energy, angle and altitude.

A method for detection of muon induced electromagnetic showers with the ANTARES detector

The primary aim of ANTARES is neutrino astronomy with upward going muons created in charged current muon neutrino interactions in the detector and its surroundings. Downward going muons are background for neutrino searches. These muons are the decay products of cosmic-ray collisions in the Earth's atmosphere far above the detector. This paper presents a method to identify and count electromagnetic showers induced along atmospheric muon tracks with the ANTARES detector. The method is applied to both cosmic muon data and simulations and its applicability to the reconstruction of muon event energies is demonstrated.

Stable operation with gain of a double phase Liquid Argon LEM-TPC with a 1 mm thick segmented LEM

In this paper we present results from a test of a small Liquid Argon Large Electron Multiplier Time Projection Chamber (LAr LEM-TPC). This detector concept provides a 3D-tracking and calorimetric device capable of charge amplification, suited for next-generation neutrino detectors and possibly direct Dark Matter searches. During a test of a 3 lt chamber equipped with a 10×10 cm2 readout, cosmic muon data was recorded during three weeks of data taking. A maximum gain of 6.5 was achieved and the liquid argon was kept pure enough to ensure 20 cm drift (O(ppb) O2 equivalent).

Drift Time measurement in the ATLAS Liquid Argon electromagnetic calorimeter using cosmic muons

In this article, measurements of the drift time (Tdrift) of the ionization electrons in the ATLAS ElectroMagnetic (EM) calorimeter are presented, using 32-samples cosmic muon data. In particular, the drift time measurement is used to assess the intrinsic uniformity of the calorimeter gaps and estimate its impact on the constant term of the energy resolution. This analysis leads to an estimated contribution to the constant term of (0.29+0.05−0.04) % in the barrel and (0.54+0.06−0.04 in the endcaps. The same data are used to measure the drift velocity of ionization electrons in liquid argon, which is found to be 4.61 ± 0.07 mm/μs at 88.5 K and 1 kV/mm.

Commissioning and first data with the ATLAS silicon microstrip tracker

The ATLAS experiment at the CERN large hadron collider (LHC) has started taking data this autumn with the inauguration of the LHC. The semiconductor tracker (SCT) is the key precision tracking device in ATLAS, made up from silicon micro-strip detectors processed in the planar p-in-n technology.The completed SCT has recently been installed inside the ATLAS experimental hall. Quick tests were performed last year to verify the connectivity of the electrical and optical services. Problems observed with the heaters for the evaporative cooling system have been resolved. This has enabled extended operation of the full detector under realistic conditions. Calibration data has been taken and analysed to determine the noise performance of the system. In addition, extensive commissioning with cosmic ray events has been performed. The cosmic muon data has been used to align the detector, to check the timing of the front-end electronics as well as to measure the hit efficiency of modules.The current status of the SCT will be reviewed, including results from the latest data-taking periods in autumn 2008, and from the detector alignment. We will report on the commissioning of the detector, including overviews on services, connectivity and observed problems. Particular emphasis will also be placed on the SCT data taken in the latest running period with the entire ATLAS detector participating. The SCT commissioning and running experience will then be used to extract valuable lessons for future silicon strip detector projects.

Performance of the ATLAS liquid argon calorimeter with cosmic muons and single LHC beam data

The Liquid Argon (LAr) calorimeter is a key detector in the ATLAS (A Toroidal LHC ApparatuS) experiment at the Large Hadron Collider (LHC), designed to provide precision measurements of electrons, photons, jets and missing transverse energy. Cosmic muon data has been recorded by the LAr calorimeter at various stages of commissioning, with the first single LHC beam data being recorded in September 2008. We present here the LAr calorimeter performance studies based on cosmic muons and LHC beam data. In 2008, ∼99% of the LAr readout channels were fully operational. The high energy deposits in the calorimeter readout cells have been used to validate the signal shape reconstruction from calibration predictions at a level better than ∼2%. The measured timing alignment agrees with expectations at the 2ns level. The non-uniformity of the barrel electromagnetic (EM) calorimeter has been estimated less than 2% thanks to cosmic muons.

Commissioning the ATLAS Silicon Microstrip Tracker

The completed SemiConductor Tracker (SCT) has been installed inside ATLAS. Tests were performed last year to verify the connectivity of the electrical and optical services. Problems observed with the heaters for the evaporative cooling system have been resolved. This has enabled extended operation of the full detector under realistic conditions. Calibration data has been taken and analyzed to determine the noise performance of the system. In addition, extensive commissioning with cosmic ray events has started. The cosmic muon data has been used to align the detector, to check the timing of the front-end electronics as well as to check hit efficiency of modules. The current status of the SCT will be reviewed.

Commissioning of the ATLAS liquid argon calorimeter

The in situ commissioning of the ATLAS liquid argon calorimeter is taking place since three years. During this period, it has been fully tested by means of frequent calibration runs, and the analysis of the large cosmic muon data samples and of the few beam splash events that occurred on September 10th, 2008. This has allowed to obtain a stable set of calibration constants for the first collisions, and to measure the in situ calorimeter performances that were found to be at the expected level.

Commissioning the ATLAS silicon microstrip tracker

The completed SemiConductor Tracker (SCT) has been installed inside ATLAS. Quick tests were performed last year to verify the connectivity of the electrical and optical services. Problems observed with the heaters for the evaporative cooling system have been resolved. This has enabled extended operation of the full detector under realistic conditions. Calibration data has been taken and analyzed to determine the noise performance of the system. In addition, extensive commissioning with cosmic ray events has started. The cosmic muon data has been used to align the detector, to check the timing of the front-end electronics as well as to measure the hit efficiency of modules. The current status of the SCT will be reviewed, including results from the latest data-taking periods. The commissioning experience will be used to extract lessons for future silicon detector projects.

The ATLAS Liquid Argon Calorimeters: integration, installation and commissioning

The ATLAS liquid argon calorimeter system consists of an electromagnetic barrel calorimeter and two end-caps with electromagnetic, hadronic and forward calorimeters positioned in three cryostats. Since May 2006 the LAr barrel calorimeter records regular calibration runs and takes cosmic muon data together with tile hadronic calorimeter in the ATLAS cavern. The cosmic runs with end-cap calorimeters started in April 2007. First results of these combined runs are presented.