| Project/Area Number |
06044205
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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 | Joint Research |
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| Research Institution | Rikkyo University |
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Principal Investigator |
MOTOBAYASHI Tohru Department of Physics, Rikkyo University Professor, 理学部, 教授 (20116114)
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| Co-Investigator(Kenkyū-buntansha) |
ARNOULD Marcel Department of Physics, Brussel Free University Professor, 理学部, 教授
BAYE D. ブリュッセル自由大学, 理学部, 教授
GALSTER W. ルーバン大学, サイクロトロン研究センター, 研究員
LELEUX P. ルーバン大学, サイクロトロン研究センター, 研究員
DELBAR Th. ルーバン大学, サイクロトロン研究センター, 副主任
KAJINO Toshitaka National Observatory Associate Professor, 助教授 (20169444)
KUBONO Shigeru Institute for Nuclear Study, University of Tokyo Assistant, 原子核研究所・核物理研究部, 助手 (20126048)
SHIMOURA Susumu Department of Physics, Rikkyo University Associate Professor, 理学部, 助教授 (10170995)
IEKI Kazuo Department of Physics, Rikkyo Univ. Associate Professor, 理学部, 助教授 (10159577)
BAYE Daniel Department of Physics, Brussels Free University Professor
GALSTER Wilfried Cyclotron Research Center, Catholic University of Louvain Researcher
LELEUX Pierre Cyclotron Research Center, Catholic University of Louvain Researcher
DELBAR Theirry Cyclotron Research Center, Catholic University of Louvain
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥10,400,000 (Direct Cost: ¥10,400,000)
Fiscal Year 1995: ¥5,100,000 (Direct Cost: ¥5,100,000)
Fiscal Year 1994: ¥5,300,000 (Direct Cost: ¥5,300,000)
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| Keywords | Nuclear astrophysics / Coulomb dissociation / (p, gamma) reaction / Unstable nuclear beam / Solar neutrino / CNO cycle / Hot pp mode / Astrophysical S-factor / 天体核物理 / 放射捕獲反応 / ガンマ線測定器系 |
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| Research Abstract |
Using beams of unstable nuclei provided by RIKEN Ring Cyclotron with intermediate energies and by Cyclotron complex of Louvain la Neuve with low energies, explosive nuclear burning processes have been studied experimentally. The Coulomb dissociation method was employed at RIKEN for an extensive study of the process ^<208>Pb(^8B,^7Be, p)^<208>Pb, which simulate the ^7Be(p, gamma)^8B reaction, a key process for the solar neutrino problem. Our results suggest very small E2 component, which has been estimated theoretically to cause a serious problem for ^8B Coulomb dissociation results. A new determination of S_<17> will be achieved by the second experiment. We also performed an experiment of ^<12>N dissociation related to the hot pp mode burning process.
A direct measurement of the reaction ^<19>Ne(p, gamma)^<20>Na was performed at Louvain la Neuve. This reaction was regarded as a key of mass flow from CNO to NeNa region. The experimental could only give an upper limit of the cross section, which is already much smaller than predictions. Another direct measurement was performed for the ^<13>N(p, gamma)^<14>O reaction, a key to ignite hot CNO cycle from the regular CNO cycle. This experiment was aimed at providing a fair and precise comparison between the Coulomb dissociation and direct capture methods by improving the accuracy of data, because both methods were once applied for the ^<13>N(p, gamma)^<14>O and the results agreed with each other within errors. A gamma-ray detection setup with a high efficiency was build at Rikkyo and brought to Louvain la Neuve to measure 5.17 MeV gamma-rays from the radiative capture reaction induced by radioactive ^<13>N beams with an hydrogen target. Analysis is in progress.
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