2005 Fiscal Year Final Research Report Summary
Determination of proton-and neutron-contributions in collective motion for neutron-rich p-sd nuclei
| Project/Area Number |
15204017
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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 |
Particle/Nuclear/Cosmic ray/Astro physics
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| Research Institution | RIKEN (2005)
The University of Tokyo (2003-2004) |
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Principal Investigator |
SAKURAI Hiroyoshi RIKEN, Radioactive Isotope Physics Laboratory, Chief Scientist, 櫻井RI物理研究室, 主任研究員 (70251395)
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| Co-Investigator(Kenkyū-buntansha) |
IWASAKI Hironori Univ.of Tokyo, School of Science, Research Associate, 大学院・理学系研究科, 助手 (30334246)
AOI Nori RIKEN, Heavy-ion Physics Laboratory, Researcher, 本林重イオン核物理研究室, 研究員 (00311647)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Radioactive Isotope Beams / Neutron-rich Nuclei / In-beam gamma spectroscopy / Recoil-shadow Method / B(E2) / proton inelastic scattering |
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| Research Abstract |
This project has provided fruitful date on nuclear structure of light and neutron-rich nuclei.
1. Lifetime Measurements for Excited States
We had made attempts to develop new methods for lifetime measurements by utilizing fast radioactive isotope (RI) beams. One of them, recoil-shadow method was upgraded and applied for excited states of ^<16,17,18>C. B(E2) values for transitions of first excited states to ground states of ^<16,18>C have been found to be very small compared with those predicted by a quantum liquid drop model. These observations suggest that proton contribution in quadruple collectivity is not large. Lifetimes of two excited states in ^<17>C were measured. We found that two transitions between tow excited states to the ground state are both M1 dominant, and one of the transitions is very small compared with a shell model calculation. The small M1 transition may stem from halo structure of the excited state.
2. Proton inelastic scattering
To deduce neutron-contribution in quadruple collectivity in ^<16>C, we performed proton inelastic scattering on ^<16>C. According to the cross section determined, we found that neutron-contribution is 7 times larger than proton one.
3. Others
We observed a new bound and excited state in ^<17>B, and constructed the excited levels in ^<17>B. We found a sudden change of nuclear structure between ^<15>B and ^<17>B over N=10. We performed beta-spectroscopy for study on nuclear structure of ^<46>Cr and ^<24>Si, and obtained new results of branching ratios as well as decay scheme.
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Research Products
(16 results)
