| Project/Area Number |
06045056
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | University-to-University Cooperative Research |
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| Research Institution | Advanced Research Center of Science and Engineering Waseda University |
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Principal Investigator |
HASEGAWA Syunichi Waseda University, Professor, 理工学総合研究センター, 教授 (10063398)
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| Co-Investigator(Kenkyū-buntansha) |
KOPENKIN V Moscow Sate University, 原子核研究所, 助手
SVESHNIKOVA L Moscow Sate University, 原子核研究所, 助教授
MANAGADZE A Moscow Sate University, 原子核研究所, 助教授
ROGANOVA T Moscow Sate University, 原子核研究所, 教授
RAKOBOLSKAYA I Moscow Sate University, 原子核研究所, 教授
ZATSEPIN G.T Moscow State University, 理学部, 教授
OHBA Ichiro Waseda University, 理工学部, 教授 (10063695)
NAMIKI Mikio Waseda University, 理工学部, 名誉教授 (80063288)
FUJIMOTO Yoichi Waseda University, 理工学総合研究センター, 名誉教授 (20063290)
SVESHINIKOVA エル モスコー大学, 原子核研究所, 助教授
MANAGDZE A. モスコー大学, 原子核研究所, 助教授
秋元 秀美 早稲田大学, 理工学総合研究センター, 助手 (40277760)
有沢 哲郎 早稲田大学, 理工学総合研究センター, 助手 (70267475)
玉田 雅宣 早稲田大学, 理工総合研究センター, 客員研究員 (70163673)
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| Project Period (FY) |
1994 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥5,100,000 (Direct Cost: ¥5,100,000)
Fiscal Year 1996: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1995: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1994: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | Cosmic-Rays / Emulsion Chambers / Cosmic-Ray families / hadron attenuation / Centauro species / Pamir / エマルシヨン・チェンバー / ウチュウセン ファミリー / ハドロン アテニュエーション / センタロウ ゾク / 宇宙線 / 宇宙線特異現象 / パミール高原 / ハドロン相互作用 / 減衰距離 |
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| Research Abstract |
The characteristics of extremely high energy hadron interactions is studied through observation of cosmic-ray families and singly arrived hadrons with thick lead x-ray chambers (60cm of Pb) exposed at Pamir altitudes (4200m). X-ray filmes about 3000 m2 have been to sent to Waseda University from Noscow State University after full processings. The total cosmic-ray exposures amount to 57 m^2year with 5 unit chambers of each 10m^2. The main results are summarized as follows.
In total 57 cosmic-ray families of visible energy not less than 100 TeV are found and measured. Energy spectra and flux of singly arrived hadrons and gamma-rays of visible energy greater than 4 TeV are obtained by total statistice of 4623 and 3097, respectively, at Pamir altitude (595 g/cm^2). It was found that the fluxes of both families and singly arrived hadrons are far less, about factor 5 or more, than expected from simulation calculations based on the assumption of normal chemical composition of primary cosmic-ra
… More
ys and ordinary type hadron interactions confirmed upto the CERN collider energy of -100TeV.
The attenuation mean free path of high energy hadrons through lead is measured and it gives the consistent balue with geometrical cross section for the hadron interactions, lambda (att) =215(]SY+-[)30g/cm<@D12@>D1 for lead. However, 140high energy hadrons (>10 TeV) in 17 super families of visible energy not less than 700 TeV shows smaller attenuation mean free path. 1 (att) =170+47-26g/cm<@D12@>D1. Such results seems to indicate characteristics of hadron interactions might be changed at much higher energies than the present accelreator experiments.
It was found there are several high energy hadron interactions which show abnormal transition behavior through chamber materials, which are never seen in simulation calculation on the basis of ordinary type hadron interactions. In order to study such abnormal characteristics of hadron interactions in different target materials from lead, X-ray films of new chambers with two storyed carbon target have been sent to Waseda from Pamir and the analysis has started and about half of total 96 m^2year exposure have been completed. The report will be presented in near future. Less
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