2002 Fiscal Year Final Research Report Summary
Study of Spin-isospin Excitation by the (p,n) Reaction in the Energy Rang in E_p=10^* 100MeV
| Project/Area Number |
13640257
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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 | Tohoku University |
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Principal Investigator |
ORIHARA Hikonojo Tohoku University, Cyclotron & Radioisotope Center, Professor, サイクロトロン・ラジオアイソトープセンター, 教授 (00004432)
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| Co-Investigator(Kenkyū-buntansha) |
SAGAWA Hiroyuki Aizu University, Computer Center, Professor, コンピュータ理工学部, 教授 (50178589)
OHNUMA Hajime Chiba Institute of Technology, Faculty of Engineering, Professor, 工学部, 教授 (00011544)
TERAKAWA Atsuki Tohoku University, Cyclotron & Radioisotope Center, Research Associate, サイクロトロン・ラジオアイソトープセンター, 助手 (10250854)
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| Project Period (FY) |
2001 – 2002
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| Keywords | (p,n) Reaction / Neutron Time-of-Flight / ^6Li(p,n)^6Be Reaction / Gamow-Teller Transition / Fermi Transition / Effective N-N Interaction / ^<42>Ca(p,n)^<42>ScReaction / V_τ / V_<στ> Ratio |
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| Research Abstract |
The experiment was performed at the Cyclotron and Radioisotope Center, Tohoku University, with a 70-MeV proton beam from the K=110MeV AVF-cyclotron and the new beam swinger system^<6)>. The details of the experimental setup have been described Ref.6. Neutron energies were measured by the time-of-flight technique (TOF), where neutrons were detected by a detector array consisting of 16peaces of the disk type detector located at 44.3 m from the target. The detectors were filled with 25.1-liter organic liquid scintillator BC501A in the total sensitive volume. The absolute efficiencies of the detectors were obtained from the ^7Li(p,n) ^7Be activation analyses with an error less than ± 6%. Errors in the absolute magnitude of (p,n) cross sections were estimated to be less than 12%. The target was a metallic foil of ^6Li isotopes with enrichments better than 95%.
The experimental study for the ^6Li(p,n)^6Be reaction has carried out at E_p=50^- 80 MeV region. Differential cross sections of neutr
… More
ons leading to the five states in the residual nucleus were measured. Results have been compared with the large-space shell-model prediction based on DW theory. The newly observed low-lying state at E_x= 3MeV has been tentatively assigned to be 2^+, T=1 one. Two broad bump observed at E_x= 15 and 25MeV were discussed as 1^- and 2^- components of the ΔL=1 giant resonance.
Experimental study of the ^<12>C(p,n)^<12>N reaction have been carried out at E_p= 70 MeV with better resolution than those so far reported. Results were compared successfully with the predictions based on large-space shell-model and DW calculations where Franey and Love 100MeV effective interactions were applied. Spin-parity assignments for observed seven transition were consistent with previous report.
The ^<42>Ca(p,n)^<42>Sc reaction at E_p = 50, 70 and 80 MeV were observed by the high resolution TOF technique. The shell model calculation and analyses with DWBA theory have provided a set of spin-parity assignment over 7, 8 and 10 levels for ^<42,44>Sc, and ^<48>Sc nuclei, respectively. The GT matrix elements B(GT) were obtainded from the LAS and the GT cross sections. The energy dependence of the ratio of isovector effective interaction strengths |J_<στ>/J_τ| was obtained for the (p,n) reaction on a medium mass nucleus in an energy range between 50 and 80 MeV. Less
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Research Products
(6 results)
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[Publications] H.Orihara, A.Terakawa, K.Itoh, H.Suzuki, K.Kumagai, Y.Kikuchi, G.C.Jon, K.Ishii, T.Niizeki, H.Sagawa, and H.Ohnuma: "Gamow-Teller matrix-elements in light nuclei and (p,n) cross-sections at E_p = 35 MeV"Physics Letters. B539. 40-44 (2002)
Description
「研究成果報告書概要(欧文)」より
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[Publications] A.Terakawa, H.Suzuki, K.Kumagai, Y.Kikuchi, T.Uekusa, T.Uemori, H.Fujisawa, N.Sugimoto, K.Itoh, M.Baba, H.Orihara and K.Maeda: "New fast-neutron time of flight facilities at CYRIC"Nuclear Instruments and Methods. A491. 419-425 (2002)
Description
「研究成果報告書概要(欧文)」より
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[Publications] A.Terakawa, H.Orihara, M.Oura, M.Hosaka, T.Tohei, T.Nakagawa, J.Takamatsu, A.Narita, K.Hosomi, K,Ishii, G.C.Jon, K.Miura, and H.Ohnuma: Physical Review. C66. 0064313 (2002)
Description
「研究成果報告書概要(欧文)」より
