2006 Fiscal Year Final Research Report Summary
Chemical composition and point source of high energy primary cosmic ray and sidereal time variation
| Project/Area Number |
15403005
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 海外学術 |
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| Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
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| Research Institution | Osaka City University |
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Principal Investigator |
HAYASHI Yoshio Osaka City University, Graduate School of Science, Prof. (00106337)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAKAMI Saburou Osaka City University, Graduate School of Science, Prof. emeritus (40047337)
OGIO Shoichi Osaka City University, Graduate School of Science, Associate Prof. (20242258)
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| Project Period (FY) |
2003 – 2006
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| Keywords | air shower / gamma ray point source / Diffuse gamma ray / primary cosmic ray composition / solar activity / India / インド |
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| Research Abstract |
We made GRAPES-3 air shower array at Ooty in southeren India, constitutes of about 350 scintillator detectors and large area (560m^2) tracking muon detector with 1GeV energy threshold. We got the angular resolution of the present GRAPES-3 experiment by using the two important methods such as EvenOdd and RightLeft methods. The results obtained from the above two methods have been compared with the outcome of the Moon and the Sun shadow observation. The angular resolution is 0.5° for>80TeV. We observed an excess flux in showers selected with 'zero-muon' and 'muon-poor' criteria. These observations yield an integral flux of (5.08±2.67)×10^<-13>cm^<-2>s^<-1> above an energy threshold of 9 TeV and (6.92±2.87)×10^<-14>cm^<-2>s^<-1> for energy above 30TeV. This is the first result with mu-less showers.
The composition and the energy spectrum of the primary cosmic rays were measured. The GRAPES-3 experiment including the details of the muon multiplicity distributions observed with a 560 m^2 muo
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n detector as a function of the shower size from the analysis. These distributions have been compared with the expectations from the Monte Carlo simulations, using some of the hadronic interaction generators available with the CORSIKA code, to deduce the energy spectra for various nuclear groups in the 100-1000 TeV region. A comparison of the GRAPES-3 results with the direct measurements indicates that the SIBYLL generator provides a good description of the hadronic interactions for the interpretation of the EAS data. These measurements extend the energy spectra and the composition of the primary cosmic rays that is consistent with extrapolation of the direct measurements.
Solar flares accelerate charged particles through a variety of mechanisms, which may be constrained through observations at high energies (>10 GeV). We observed a search for direct emission of protons of energy>20 GeV in association with an X17 class solar flare that occurred on 28 October 2003, using a large area tracking muon telescope of the GRAPES-3 experiment. The telescope has high sensitivity search for the directional enhancement of the solar protons and got upper limit on the flux of protons due to the solar flare. Less
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Research Products
(16 results)
