Observations on muon multiplicity distribution with the GRAPES-2 experiment at Ooty for studies on the mass composition of cosmic rays at PeV energies

Gupta, S. K.; Gopalakrishnan, N. V.; John, A.; Mohanty, D. K.; Morris, S. D.; Ravindran, K.; Sivaprasad, K.; Sreekantan, B. V.; Srivatsan, R.; Tonwar, S. C.

doi:10.1103/physrevd.68.052005

Cited by 15 publications

(9 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some of our earlier results [10] based on the Monte Carlo simulations had indicated that the shape of the muon multiplicity distribution (MMD) measured with a large area muon detector was a sensitive probe of the relative mix of different nuclei in the primary cosmic ray flux [89]. Following this indication, we have attempted to extract the energy spectrum of the protons and other nuclei through a comparison of the observed MMDs with the expectations from the Monte Carlo simulations, for different models of hadronic particle interactions as discussed in the subsequent sections.…”

Section: Cosmic Ray Compositionmentioning

confidence: 83%

“…837 [64,65] and the GRAPES-2 [10] are the other recent experiments using either a large area muon detector or an array of muon detectors with the capability to observe the muon-poor showers. However, the GRAPES-3 experiment [61] with its single large area (560 m 2 ) muon detector is attempting to reach a significantly higher level of sensitivity to the γ-initiated showers based on their small muon content, particularly at the sub-PeV energies, lower than those achieved by the CASA-MIA experiment.…”

Section: High Energy Astroparticle Physics At Ooty and The Grapes-3 Ementioning

confidence: 99%

“…Using a single large area muon detector, such as in the EAS-TOP experiment [74], the muon size has been estimated for individual showers from the lateral distribution function obtained from a fit to the data. On the other hand, the GRAPES-2 [10] experiment had made a detailed study of the muon multiplicity distribution in an attempt to obtain the flux of the light nuclei (H+He+CNO groups) and the heavy nuclei (Si+Fe groups) in the cosmic rays almost independently. Pursuing the strategy of the GRAPES-2, the GRAPES-3 collaboration has constructed a large, 560 m 2 area, muon detector to study the muon multiplicity distribution for showers over a wide energy range.…”

Section: High Energy Astroparticle Physics At Ooty and The Grapes-3 Ementioning

confidence: 99%

“…factors of >10 7 m 2 h are achieved [6][7][8][9][10][11]. However, with the exception of the Tibet-ASg and ARGO-YBJ experiments [8,9], the energy thresholds for most of the EAS arrays are significantly higher than the highest energy cosmic rays observed in the direct measurements.…”

mentioning

confidence: 99%

“…The recent results from the Monte Carlo simulations have shown that the shape of the MMD measured with a large area muon detector possesses excellent sensitivity to the composition of the primary cosmic rays [10]. This is primarily because the lighter nuclei, such as the proton (H) and helium (He) etc.…”

mentioning

confidence: 99%

See 4 more Smart Citations

High Energy Astroparticle Physics at Ooty and the GRAPES-3 Experiment

Gupta¹

2014

Proceedings of the Indian National Science Academy

Self Cite

View full text Add to dashboard Cite

The astroparticle studies at Ooty have their roots going way back into the fifties, when studies using cosmic rays were initiated with cloud chambers of progressively larger sizes as the primary detector and measuring device to obtain properties of hadrons at high energies. This study was subsequently strengthened with the installation of a total absorption calorimeter and a modest extensive air shower array to probe the composition of the primary cosmic rays to very high energies. The discovery of pulsars provided a thrust for the exploration of these compact objects as the sources of γ-rays at TeV energies with the aid of atmospheric Cerenkov detectors in the seventies. With the rapid technological advances occurring during the subsequent years in detectors, electronics and computers, physicists world-wide were able to set up very large and remarkably sensitive experiments that were hard to imagine a decade earlier. With the increasing sophistication and complexity the modern experiments require participation of very large teams of scientists. This development has made the formation of collaboration of large number of physicists both experimental and theoretical, engineers, technicians etc., from a number of institutions and universities, a prerequisite for setting up any major experimental facility. The GRAPES-3 experiment is a collaboration of 34 scientists from 13 institutions, including 8 from India and 5 from Japan. The GRAPES-3 experiment contains a dense extensive air shower array operating with ~ 400 scintillator detectors and a 560 m 2 tracking muon detector (Em > 1 GeV), at Ooty in India. 25 % of scintillator detectors are instrumented with two fast photomultiplier tubes (PMTs) for extending the dynamic range to ~ 5x10 3 particles m -2. The scintillators, signal processing electronics and data recording systems were fabricated in-house to cut costs and optimize performance. The muon multiplicity distribution of the EAS is used to probe the composition of primary cosmic rays below the 'knee', with an overlap with direct measurements. Search for multi-TeV γ-rays from point sources is done with the aid of the muon detector. A good angular resolution of 0.7 o at 30 TeV, is measured from shadow of the Moon on the isotropic flux of cosmic rays. Sensitive limit on the diffuse flux of 100 TeV γ-rays is placed by using muon detector to filter out the charged cosmic ray background. The tracking muon detector allows sensitive measurements on the coronal mass ejections and solar flares through Forbush decrease events. We have major expansion plans to enhance the sensitivity of the GRAPES-3 experiment in the areas listed above. PACS

show abstract

Section: Cosmic Ray Compositionmentioning

confidence: 83%