Magnetized Iron Calorimeter Detector Research Articles

Simulation analysis with rock muons from atmospheric neutrino interactions in the ICAL detector at the India-based Neutrino Observatory

The proposed magnetized Iron CALorimeter detector (ICAL) to be built in the India-based Neutrino Observatory (INO) laboratory aims to study atmospheric neutrinos and its properties such as precision measurements of oscillation parameters and the neutrino mass hierarchy. High energy charged current (CC) interactions of atmospheric neutrinos with the rock surrounding the detector produce so-called “rock muons” along with hadrons. While the hadron component of these events are absorbed in the rock itself, the rock muons traverse the rock and are detected in the detector. These rock muon events can be distinguished from cosmic muons only in the upward direction and can provide an independent measurement of the oscillation parameters. A simulation study of these events at the ICAL detector shows that, although reduced in significance compared to muons produced in direct CC neutrino interactions with the detector, these events are indeed sensitive to the oscillation parameters, achieving a possible 1σ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$1\\sigma $$\\end{document} precision of 10% and 27% in determining Δm322\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\varDelta m_{32}^2$$\\end{document} and sin2θ23\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sin ^2\ heta _{23}$$\\end{document}, respectively. Hence a combination of the standard atmospheric neutrino analysis which is the main goal of ICAL, with these rock muon events, will improve the precision reach of ICAL for these parameters.

Effect of variations in the gas mixture compositions on the timing and charge of glass RPC

The India-based Neutrino Observatory (INO) is a project aimed at building a large underground laboratory to explore the Earth's mater effects on the atmospheric neutrinos in multi-GeV range. INO will host a 50 kton magnetized iron calorimeter detector (ICAL) in which Resistive Plate Chambers(RPCs) will be the active detector elements. In ICAL, 28,800 glass RPCs of 2 m × 2 m size will be operated in the avalanche mode. A small variation in the compositions of ionizing gaseous medium in the RPC affects its performance. Study of the charge distribution of the RPC at different gas compositions is necessary to optimize the gas mixture. An RPC made with glass plates of dimension 30 cm × 30 cm was operated in avalanche mode with a gas mixture of C2H2F4/iC4H10/SF6. We have studied the performance of these RPCs at the same ambient conditions. The percentages of the iC4H10 or SF6 were varied and its effect on the performance of RPC were studied. The study of the charge distribution and time resolution of the RPC signals at different gas compositions is presented in this paper.

Independent measurement of muon neutrino and antineutrino oscillations at the INO–ICAL experiment

The magnetized iron calorimeter detector at the India-based neutrino observatory (INO) has a unique feature to identify the neutrinos and antineutrinos on an event by event basis. This feature can be harnessed to detect the differences between the oscillation parameters of neutrinos and antineutrinos independently. In this paper, we analyzed charged current νμ and events under the influence of earth matter effect using three neutrino flavor oscillation framework. If the atmospheric mass-squared differences and mixing parameters for neutrinos are different from antineutrinos, we present the prospects for the experimental observation of these differences in atmospheric ν and oscillations at INO. We estimate the detector sensitivity to confirm a non-zero difference in the mass-squared splittings () for neutrinos and antineutrinos.

Testing and Integration of Front End Electronics for INO-ICAL RPCs

The India based Neutrino Observatory (INO) is an multi institutional facility that involves the construction of a underground laboratory for the basic research in neutrino physics. The magnetized Iron Calorimeter (ICAL) detector is the primary experiment in this facility and is going to shed light on many important issues related to the atmospheric neutrinos. The ICAL geometry is going to utilize about 29000 single gap Resistive Plate Chambers (RPCs) as triggering and tracking elements. The ICAL RPC will have two dimensional readout and comprising of 64 readout channels in each plane. The complete readout of the ICAL detector requires the implementation of millions of electronic readout channels. In order to cope up with enormous number of electronics channels, a multichannel based front end ASIC namely HARDROC has been tested and commissioned. The study incorporates the various calibration tests concerning the different parameters of HARDROC. Finally the first ever performance results of single gap glass based RPC using HARDROC as front end electronics are presented.

The Status of INO

The India-based Neutrino Observatory (INO) is a proposed project to observe atmospheric neutrinos using a magnetized iron calorimeter (ICAL) detector. The unique feature of this detector is the ability to study neutrinos and antineutrinos separately owing to its charge identification capability. This makes it a very suitable detector to study the ordering of the neutrino mass states. Its other physics goals include precision measurement of atmospheric neutrino oscillation parameters, finding the octant of θ23 etc. In this talk I summarize the current status of the INO project and the R&D work that is underway to achieve its physics goals.

Indirect searches of Galactic diffuse dark matter in INO-MagICAL detector

The signatures for the existence of dark matter are revealed only through its gravitational interaction. Theoretical arguments support that the Weakly Interacting Massive Particle (WIMP) can be a class of dark matter and it can annihilate and/or decay to Standard Model particles, among which neutrino is a favorable candidate. We show that the proposed 50 kt Magnetized Iron CALorimeter (MagICAL) detector under the India-based Neutrino Observatory (INO) project can play an important role in the indirect searches of Galactic diffuse dark matter in the neutrino and antineutrino mode separately. We present the sensitivity of 500 kt·yr MagICAL detector to set limits on the velocity-averaged self-annihilation cross-section (〈σv〉) and decay lifetime (τ ) of dark matter having mass in the range of 2 GeV ≤ mχ ≤ 90 GeV and 4 GeV ≤ mχ ≤ 180 GeV respectively, assuming no excess over the conventional atmospheric neutrino and antineutrino fluxes at the INO site. Our limits for low mass dark matter constrain the parameter space which has not been explored before. We show that MagICAL will be able to set competitive constraints, 〈σv〉 ≤ 1.87 × 10−24 cm3 s−1 for chi chi to nu overline{nu} and τ ≥ 4.8 × 1024 s for chi to nu overline{nu} at 90% C.L. (1 d.o.f.) for mχ = 10 GeV assuming the NFW as dark matter density profile.

Development and characterization of single gap glass RPC

India-based Neutrino Observatory (INO) facility is going to have a 50kton magnetized Iron CALorimeter (ICAL) detector for precision measurements of neutrino oscillations using atmospheric neutrinos. The proposed ICAL detector will be a stack of magnetized iron plates (acting as target material) interleaved with glass Resistive Plate Chambers (RPCs) as the active detector elements. An RPC is a gaseous detector made up of two parallel electrode plates having high bulk resistivity like that of a float glass and bakelite. For the ICAL detector, glass is preferred over bakelite as it does not need any kind of surface treatment to achieve better surface uniformity and also the cost of associated electronics is reduced. Under the detector R&D efforts for the proposed glass RPC detector, a few glass RPCs of 1m × 1m dimension are fabricated procuring glass of ∼2mm thickness from one of the Indian glass manufacturers (Asahi). In the present paper, we report the characterization of RPC based on leakage current, muon detection efficiency and noise rate studies with varying gas compositions.

Effect of glass thickness variations on the performance of RPC detectors

The India-based Neutrino Observatory (INO) is planning to build a magnetized iron calorimeter detector (ICAL) in which Resistive Plate Chambers (RPCs) will be the active detector elements. A study of the performance of RPCs, made using electrodes of various thicknesses, is pivotal in optimizing the design parameters of the ICAL RPCs. We fabricated RPCs with glasses of various thicknesses and studied their performance in the same environmental conditions. A study of detector efficiency, noise rate, time resolution and charge distribution is presented in this paper.

Precision measurement of neutrino oscillation parameters @ INO-ICAL detector

Atmospheric neutrino experiments have the potential to measure the neutrino mixing parameters and mass hierarchy through the observation of earth matter effects. The magnetised Iron CALorimeter detector (ICAL) at the India-based Neutrino Observatory (INO) is one of the best experiments to separate the νμ and ν‾μ with its excellent charge identification capabilities. We show the oscillation sensitivity of ICAL detector for the precision measurement of atmospheric mixing parameters |Δm322| and sin2⁡θ23. The Monte Carlo simulation for NUANCE generated atmospheric νμ and ν‾μ events and a marginalised χ2 analysis using realistic detector resolutions and efficiencies has been performed. We show the expected improvement in the precision measurement of these parameters using reconstructed neutrino energy (Eν) and muon direction (cos⁡θμ) observables.

RPC detector characteristics and performance for INO-ICAL experiment

The India-based Neutrino Observatory (INO) is an approved multi-institutional collaboration neutrino physics project, aimed at building an underground laboratory in the southern India. INO will utilize a large magnetized Iron Calorimeter (ICAL) detector to study the atmospheric neutrinos, and to explore the unresolved issues related to neutrinos. The Resistive Plate Chambers (RPCs), interleaved in between iron absorber layers, are going to be used as the active signal readouts for the ICAL experiment at INO. The research and development is carried out to find structural quality and electrical response for RPC electrode materials available within local domain. The assembled 2 mm gap RPCs are tested using cosmic muons for their detection performance. The study also incorporates preliminary results on detector timing and signal induced charge measurements.

Simulations study of muon response in the peripheral regions ofthe Iron Calorimeter detector at the India-based Neutrino Observatory

The magnetized Iron CALorimeter detector (ICAL) which is proposed to be built in the India-based Neutrino Observatory (INO) laboratory, aims to study atmospheric neutrino oscillations primarily through charged current interactions of muon neutrinos and anti-neutrinos with the detector. The response of muons and charge identification efficiency, angle and energy resolution as a function of muon momentum and direction are studied from GEANT4-based simulations in the peripheral regions of the detector. This completes the characterisation of ICAL with respect to muons over the entire detector and has implications for the sensitivity of ICAL to the oscillation parameters and mass hierarchy compared to the studies where only the resolutions and efficiencies of the central region of ICAL were assumed for the entire detector.Selection criteria for track reconstruction in the peripheral region of the detector were determined from the detector response. On applying these, for the 1–20 GeV energy region of interest for mass hierarchy studies, an average angle-dependent momentum resolution of 15–24%, reconstruction efficiency of about 60–70% and a correct charge identification of about 97% of the reconstructed muons were obtained. In addition, muon response at higher energies upto 50 GeV was studied as relevant for understanding the response to so-called rock muons and cosmic ray muons. An angular resolution of better than a degree for muon energies greater than 4 GeV was obtained in the peripheral regions, which is the same as that in the central region.

Characterization of 3 mm glass electrodes and development of RPC detectors for INO-ICAL experiment

India-based Neutrino Observatory (INO) is a multi-institutional facility, planned to be built up in South India. The INO facility will host a 51kton magnetized Iron CALorimeter (ICAL) detector to study atmospheric muon neutrinos. Iron plates have been chosen as the target material whereas Resistive Plate Chambers (RPCs) have been chosen as the active detector element for the ICAL experiment. Due to the large number of RPCs needed (~28,000 of 2m×2m in size) for ICAL experiment and for the long lifetime of the experiment, it is necessary to perform a detailed R&D such that each and every parameter of the detector performance can be optimized to improve the physics output. In this paper, we report on the detailed material and electrical properties studies for various types of glass electrodes available locally. We also report on the performance studies carried out on the RPCs made with these electrodes as well as the effect of gas composition and environmental temperature on the detector performance. We also lay emphasis on the usage of materials for RPC electrodes and the suitable environmental conditions applicable for operating the RPC detector for optimal physics output at INO-ICAL experiment.

A simulations study of the muon response of the Iron Calorimeterdetector at the India-based Neutrino Observatory

The magnetised Iron CALorimeter detector (ICAL), proposed to be builtat the India-based Neutrino Observatory (INO), is designed to studyatmospheric neutrino oscillations. The ICAL detector is optimized tomeasure the muon momentum, its direction and charge. A GEANT4-basedpackage has been developed by the INO collaboration to simulate the ICALgeometry and propagation of particles through the detector. The simulatedmuon tracks are reconstructed using the Kalman Filter algorithm. Herewe present the first study of the response of the ICAL detector tomuons using this simulations package to determine the muon momentumand direction resolutions as well as their reconstruction and chargeidentification efficiencies. For 1–20 GeV/c muons in the central regionof the detector, we obtain an average angle-dependent momentum resolutionof 9–14%, an angular resolution of about a degree, reconstructionefficiency of about 80% and a correct charge identification of about98%.

Can atmospheric neutrino experiments provide the first hint of leptonicCPviolation?

The measurement of a nonzero value of the 1--3 mixing angle has paved the way for the determination of leptonic $CP$ violation. However, the current generation long-baseline experiments T2K and $\mathrm{NO}\ensuremath{\nu}\mathrm{A}$ have limited sensitivity to ${\ensuremath{\delta}}_{CP}$. In this paper, we show, for the first time, the significance of atmospheric neutrino experiments in providing the first hint of $CP$ violation in conjunction with T2K and $\mathrm{NO}\ensuremath{\nu}\mathrm{A}$. In particular, we find that adding atmospheric neutrino data from a magnetized iron calorimeter detector at the India-Based Neutrino Observatory to T2K and $\mathrm{NO}\ensuremath{\nu}\mathrm{A}$ results in a twofold increase in the range of ${\ensuremath{\delta}}_{CP}$ values for which a $2\ensuremath{\sigma}$ hint of $CP$ violation can be obtained. In fact, in the parameter region unfavorable for the latter experiments, the first signature of $CP$ violation may well come from the inclusion of atmospheric neutrino data.

Study of the directionality of cosmic muons using the INO-ICAL prototype detector

The India-based Neutrino Observatory (INO) collaboration is planning to build a magnetised Iron-CALorimeter detector (ICAL) to study atmospheric neutrino oscillations with high precision. The ICAL adopts a 50kton iron target and about 28800 Resistive Plate Chambers (RPC) of 2×2m2 in area as active detector elements. As part of its R&D programme, a prototype detector stack composed of 12 layers of glass RPCs of 1×1m2 in area has been set up at the Tata Institute of Fundamental Research (TIFR) to study the detector parameters using cosmic muons. We present here a study of the capability of this prototype detector to distinguish between up-going and down-going muons.

Electronics and data acquisition system for the ICAL prototype detector of India-based neutrino observatory

The India-based Neutrino Observatory (INO) collaboration has proposed to build a 50kton magnetized Iron Calorimeter (ICAL) detector with the primary goal to study neutrino oscillations, employing Resistive Plate Chambers (RPCs) as active detector elements. A prototype of the ICAL detector has been built in order to develop and characterize the intrinsic sub-systems, like RPCs, gas system, electronics and data acquisition system, etc. This paper describes in detail the readout electronics as well as the VME-based data acquisition system for the prototype detector.

Toward the implementation of the trigger scheme for the ICAL detector of India-based Neutrino Observatory

The India-based Neutrino Observatory (INO) collaboration has proposed to build a 50kton magnetized Iron Calorimeter (ICAL) detector with the primary goal to study neutrino oscillations, employing Resistive Plate Chambers (RPCs) as active detector elements. The architecture of the ICAL trigger scheme has already been validated and the results are reported in a previous paper. As a first step toward the implementation of the trigger scheme, we have designed an FPGA-based trigger module and deployed it in the prototype detector. In this paper, the design features of the trigger module are described and some evaluation results are presented. A design for the implementation of the proposed trigger scheme for a larger prototype of the ICAL detector, known as the ICAL Engineering Module, is also discussed.

Development of trigger scheme for the ICAL detector of India-based Neutrino Observatory

The India-based Neutrino Observatory (INO) collaboration has proposed to build a 50kton magnetized Iron Calorimeter (ICAL) detector with the primary goal to study neutrino oscillations, employing Resistive Plate Chambers (RPCs) as active detector elements. Various aspects of a proposed trigger scheme for the ICAL detector are discussed. The associated chance trigger rates are calculated and the trigger efficiency of the scheme for the events of interest for the ICAL detector is determined. An approach toward the implementation of the scheme is also presented.

Long-range forces: atmospheric neutrino oscillation at a magnetized detector

Among the combinations Le-Lμ, Le-Lτ and Lμ-Lτ any one can be gauged in anomaly free way with the standard model gauge group. The masses of thesegauge bosons can be so light that it can induce long-range forces on the Earth due to theelectrons in the Sun. This type of forces can be constrained significantlyfrom neutrino oscillation. As the sign of the potential is opposite for neutrinos and antineutrinos, a magnetized iron calorimeter detector (ICAL) would be able to produce strong constraint on it. We have made conservative studies of these long-range forces with atmospheric neutrinos at ICAL considering only the muons of charge current interactions.We find stringent bounds on the couplings αeμ,eτ ⪅ 1.65 × 10−53 at 3σ CL with an exposure of 1 Mton·yr if there is no such force. For nonzero input values of the couplings we find thatthe potential Veμ opposes and Veτ helps to discriminate the mass hierarchy.However, both potentials help significantly to discriminate the octant of θ23. The explanation of the anomaly in recent MINOS data (the difference of Δm322 for neutrinos and antineutrinos), using long-range force originated from the mixing of the gauge boson Z′ of Lμ-Lτ with the standard model gauge boson Z,can be tested at ICAL at more than 5σ CL. We have also discussed how to disentangle this from the solution with CPT violationusing the seasonal change of the distance between the Earth and the Sun.

Neutrino probes of the nature of light dark matter

Dark matter particles gravitationally trapped inside the Sun may annihilate into Standard Model particles, producing a flux of neutrinos. The prospects of detecting these neutrinos in future multi-kt neutrino detectors designed for other physics searches are explored here. We study the capabilities of a 34/100 kt liquid argon detector and a 100 kt magnetized iron calorimeter detector. These detectors are expected to determine the energy and the direction of the incoming neutrino with unprecedented precision allowing for tests of the dark matter nature at very low dark matter masses, in the range of 10–25 GeV. By suppressing the atmospheric background with angular cuts, these techniques would be sensitive to dark matter-nucleon spin-dependent cross sections at the fb level, reaching down to a few ab for the most favorable annihilation channels and detector technology.