| Project/Area Number |
13640303
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | KONAN UNIVERSITY |
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Principal Investigator |
UTSUNOMIYA Hiroaki KONAN UNIVERSITY, DEPARTMENT OF PHYSICS, PROFESSOR -> 甲南大学, 理工学部, 教授 (00241167)
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| Co-Investigator(Kenkyū-buntansha) |
OHGAKI Hideaki KYOTO UNIVERSITY, INSTITUTE OF ADVANCE ENERGY, ASSOCIATE PROFESSOR, エネルギー理工学研究所, 助教授 (10335226)
AKIMUNE Hidetoshi KONAN UNIVERSITY, DEPARTMENT OF PHYSICS, ASSOCIATE PROFESSOR, 理工学部, 助教授 (60319829)
YAMAGATA Tamio KONAN UNIVERSITY, DEPARTMENT OF PHYSICS, PROFESSOR, 理工学部, 教授 (50068144)
TOYOKAWA Hiroyuki NATIONAL INSTUTUTE OF ADVANCED INDUSTRIAL SCIEINCE AND TECHNOLOGY, PHOTONICS RESEARCH INSTITUTE, RESEARCHER, 光技術部門, 研究員
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| Project Period (FY) |
2001 – 2003
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| Keywords | photo disintegration / nuclear astrophysics / origin of elements / nucleosynthesis / p-process / s-process / big bane / laser inverse Compton scattering |
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| Research Abstract |
Quasi-monochromatic y rays produced from laser inverse-Compton scattering at AIST(National Institute of Advanced Industrial Science and Technology) were used to photo-disintegrate 1)^9Be of interest for nucleosynthesis in type II supernovae, 2)^<181>Ta for the p-process nucleosynthesis, 3)D for big bang nucleosynthesis, and 4) ^<186>W for the s-process nucleosynthesis. The following results were obtained.
1)^9Be : Photoneutron cross sections were measured at energies from threshold to 6.1MeV. Electromagnetic reduced transition probabilities were determined for the 1/2^+,5/2^-,5/2^+ states in ^9Be and the astrophysical reaction rate for αα(n,γ)^9Be were evaluated.
2)^<181>Ta : Photoneutron cross sections were measured at energies from threshold to 12MeV. The p-process origin of ^<180>Ta in O/Ne rich layers during explosions of massive stars as type II supernovae was discussed based on the Hauser-Feshbach model calculation with the QRPAγ strength function.
3)D : Photoneutron cross sections were measured at energies from threshold to 4.6MeV. The reaction rate for p(n,γ)D was determined with 6% uncertainty in the energy region relevant to big bang nucleosynthesis, providing an experimental foundation for theoretical reaction rates.
4)^<186>W : Photoneutron cross sections were measured at energies from threshold to 10.8MeV. Neutron-capture cross sections for a radioactive ^<185>W nucleus(T_<1/2>=75 days) were evaluated at 30keV using the Hauser-Feshbach statistical model. Constraints on neutron density allowed in s-process models were provided.
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