| Project/Area Number | 08404012 |
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
素粒子・核・宇宙線
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| Research Institution | HIROSAKI UNIVERSITY |
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Principal Investigator |
NANJO Hirotada Hirosaki University, Faculty of Science and Technology, Professor, 理工学部, 教授 (00106840)
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| Co-Investigator(Kenkyū-buntansha) |
MATUTANI Hideya HIROSAKI UNIVERSITY, SCHOOL OF MEDICINE, INSTRUCTOR, 医学部, 助手 (30241483)
ICHIMURA Masakatu HIROSAKI UNIVERSITY, FACULTY OF SCIENCE AND TECHNOLOGY, ASSOCIATE PROFESSOR, 理工学部, 助教授 (20232415)
KURAMATA Syuichi HIROSAKI UNIVERSITY, FACULTY OF SCIENCE AND TECHNOLOGY, PROFESSOR, 理工学部, 教授 (10215048)
KAMIOKA Eiji NATIONAL CENTER FOR SCIENCE INFORMATION SYSTEMS, 研究開発部, 助手 (90311175)
SHIBATA Tooru AOYAMA GAKUIN UNIVERSITY, COLLEGE OF SCIENCE AND ENGINEERING, INSTRUCTOR, 理工学部, 助手 (70082831)
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| Project Period (FY) |
1996 – 1999
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| Project Status |
Completed(Fiscal Year 1999)
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| Budget Amount *help |
¥40,700,000 (Direct Cost : ¥40,700,000)
Fiscal Year 1999 : ¥8,400,000 (Direct Cost : ¥8,400,000)
Fiscal Year 1998 : ¥8,600,000 (Direct Cost : ¥8,600,000)
Fiscal Year 1997 : ¥8,600,000 (Direct Cost : ¥8,600,000)
Fiscal Year 1996 : ¥15,100,000 (Direct Cost : ¥15,100,000)
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| Keywords | Cosmic-ray / Energy Spectrum / Observation by Balloon / Emulsion Chamber |
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| Research Abstract |
In cosmic ray study, there has been a long standing problem, the cause of the knee -- the break of the spectrum around 10 (15)$ eV. Although this is one of the most important problem in cosmic ray study, the lack or the direct observation make it impossible to draw the concrete picture of the knee. So as to solve this problem, the observations or chemical compositions and energy spectrum measurements have been carried out by using the balloon borne emulsion chambers since 1995 as the collaboralion or Japan and Russia.
The balloons were launched twice in 1995, twice in 1996, three times in 1997 and 4 times in 1999, 11 times in total. All are successful flights and recoveries except only one time 1997. The flight duration is typically about 160 hours from Kamchatuka peninsula to Volga river region.
Japanese and Russian collaborators visit each other to discuss the analysis and scientific results as well as for depacking chambers and processing or photographic materials. Specially November l999, we had the workshop to study RUNJOB results, comparing those or JACEE, SOKOL and others in Hirosaki. At this workshop, the significance and reliability of the results and future problems were discussed extensively.
The data up to 1996 campaigns are analyzed and the results were reported at the international cosmic ray conference in 1997 and 1999. Our results are consistent with the extrapolation from the lower energy region. As for the proton spectrum, the agreement is good among JACEE, SOKOL and ours, but our helium spectrum is lower than others by factor 2. And the paper on these results are submitted to Astro-Particle Physics February in 2000.
The analysis or 1997 and 1999 data is going on now. 1997 analysis is very close to the completion and the first-stage analysis or 1999 data is finished. The final results will be published in two years.
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