| Project/Area Number |
08454069
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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 | 一般 |
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| Research Field |
素粒子・核・宇宙線
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| Research Institution | RIKKYO UNIVERSITY |
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Principal Investigator |
MOTOBAYASHI Toru RIKKYO UNIV., COLLEGE OF SCIENCE,PROFESSOR, 理学部, 教授 (20116114)
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| Co-Investigator(Kenkyū-buntansha) |
SAKURAGI Hiroyuki OSAKA CITY UNIV., FACULTY OF SCIENCE,ASSISTANT PROF., 理学部, 助教授 (90183821)
IZUMOTO Toshiaki RIKKYO UNIV., COLLEGE OF SCIENCE,PROFESSOR, 理学部, 教授 (80193382)
SHIMOURA Susumu RIKKYO UNIV., COLLEGE OF SCIENCE,ASSISTANT PROF., 理学部, 助教授 (10170995)
IEKI Kazuo RIKKYO UNIV., COLLEGE OF SCIENCE,ASSISTANT PROF., 理学部, 助教授 (10159577)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥7,000,000 (Direct Cost: ¥7,000,000)
Fiscal Year 1997: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1996: ¥6,600,000 (Direct Cost: ¥6,600,000)
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| Keywords | Coulomb dissociation / E2 component / angular distribution / ^7Be(P,gamma)^8B reaction / ^8Be(P,gamma)^9B reaction / large vacuum chamber / solar neutrino / hot pp mode / クーロン分解反応 / 放射捕獲反応 / hot pp chain / 不安定核 / 角度相関 / バックグラウンド / 反応機構 / 核力分解 / クラスターモデル / 液体水素標的 / 冷凍機 / 大型真空槽 / 光電子増倍管 / 光減衰 |
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| Research Abstract |
Reaction mechanism of intermediate-energy Coulomb dissociation has been studied by precise measurements of angular distribution and angular correlation of the fragments. A large vacuum chamber has been constructed as a housing of a plastic scintillator hodoscopes. The chamber was installed in a experimental hail of RIKEN Accelerator Research Facility, and was used for experiments with radioactive nuclear beams. Background-free measurements become possible for the relative energy lower than 0.5 MeV.
The ^<208>Pb(^8B, ^7Be p)^<208>Pb and ^<208>Pb(^9C, ^8B p) ^<208>Pb reactions were studied. The primary aim of the measurements are to determine the ^7Be (p, gamma)^8B and ^8B(p, gamma)^9C reactions. The former reaction produce high-energy solar-neutrinos, and the latter is a key reaction in the hot pp mode nuclear burning in stars. In the Coulomb dissociation method, a one-step El transition mechanism is assumed in the process of extracting the (p, gamma) cross section. However, possible small mixture of E2 transition had been pointed out. We notice that the fragments' angular distributions are different for El and E2 transitions. In the measurements, the scattering angle up to 100 was covered by the new setup to obtain complete distributions. The results suggested very small E2 components which do not affect the extracted (p, gamma) cross sections.
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