1993 Fiscal Year Annual Research Report

極端状況下の原子核の構造と相互作用

Research Project

Project/Area Number	05243102
Research Institution	The University of Tokyo
Principal Investigator	石原正泰東京大学, 大学院・理学系研究科, 教授 (40013396)
Co-Investigator(Kenkyū-buntansha)	堀内昶京都大学, 理学部, 助教授 (60027349) 大塚孝治東京大学, 大学院・理学系研究科, 助教授 (20201379) 郷農靖之九州大学, 理学部, 助教授 (50016127) 谷畑勇夫理化学研究所, 主任研究員 (10089873) 福田共和東京大学, 原子核研究所, 助教授 (50116092)
Keywords	超重元素 / 中性子過剰核 / 高スピン核異性体 / 不安定核 / 反対称化分子動力学 / 分解反応 / 核構造 / 加速器技術
Research Abstract	「超重元素探索」:(HI,αxn)反応による超重元素合成の新しいアプローチを進め、その予備的実験を実施した。ビーム強度とS/Nの向上をはかるために同位体分離装置GARISとその測定器部分の改良を行なった。^<232>Th(^<36>Ar,α2n)^<262>106反応のテスト実験を成功させ、副産物として新同位元素^<200>Frを発見した。また、検出効率の高い新しい大型のガス検出器の製作、読み出し回路の開発を行なった。「中性子過剰核」:中性子過剰核の弾性散乱と非弾性散乱の実験を進めた。特に^8He非弾性散乱の実験では2.3MeVの共鳴励起状態を発見、確立させた。また、核子移行反応(d,p)、核子準弾性散乱(p,pn),(p,2p)、の実験のための装置作りを進め、SSD検出器とそれを用いて角度分布の測定を行なうための真空箱を製作した。「高スピン原子核」:高スピン核異性体ビーム装置の最適化をはかり、2次ビームのサイズを35mmφから10mmφ以下に改善し、10^5sec^<-1>のビーム強度を達成した。ドップラー効果補正用の新型Ge検出器の性能をシミュレーションで求め、S/Nのよいスペクトルが得られることがわかったので、この新型検出器を製作した。「不安定核の理論」:東京大学・京都大学・新潟大学にワークステーションの配備を行なった。東京大学のグループでは、時間に依存するハートリーフォック計算やハートリーフォック法にTDA及びRPA法を組み合わせた計算などにより、中性子スキンや中性子ハローを持った中性子過剰核の性質を調べた。京都大学のグループは反対称化分子動力学により、Li、Be、Bの同位体の研究を行なった。また、重イオン反応の研究では、クラスターフローが核物質状態方程式への重要情報を与えることを示した。新潟大学のグループは、中高エネルギーの破砕反応での破砕片の運動量分布及び粒子放出を伴って連続状態へ遷移するベータ崩壊スペクトルを取り上げ、ハロー中性子の相関構造に関する知見を引き出すことができた。

Research Products
(28 results)

All Other

All Publications (28 results)

[Publications] H.Sagawa: "Gamow-Teller States in Light Nuclei near the Neutron Drip Line" Physics Letters. B303. 215-219 (1993)
[Publications] T.Nomura: "Study of α Decays Following ^<40>Ar Bombardment on ^<238>U" Proceedings of RIKEN International Workshop on Heavy-Ion Reactions with Neutron-Rich Beams. (to be published).
[Publications] T.Fukuda: "Heavy Ion Fusion with Neutron-Rich Beams" Proceedings of RIKEN International Workshop on Heavy-Ion Reactions with Neutron-Rich Beams. (to be published).
[Publications] T.Nomura: "Study of α Decays Following ^<40>Ar Bombardment on ^<238>U" RIKEN Accelerator Progress Report (1993). (to be published).
[Publications] A.Yoshida: "Measurement of the Fusion Cross Section of ^<27>Al+^<197>Au using MWPC and Multi-target System" RIKEN Accelerator Progress Report (1993). (to be published).
[Publications] S.Hirenzaki: "Proton Elastic Scattering with ^9Li and ^<11>Li and its Halo Structure" Nuclear Physics. A552. 57-65 (1993)
[Publications] I.Tanihata: "Radioactive Beam Facilities and Their Physics Program" Nuclear Physics. A553. 361-372 (1993)
[Publications] B.M.Young: "Strong Isomer Production in Fragmentation Reactions" Physics Letters. B311. 22-26 (1993)
[Publications] D.Hirata: "Systematic Study of Sr Isotopes in the Relativistic Mean Field Theory" Physics Letters. B314. 168-172 (1993)
[Publications] A.A.Korsheninnkov: "Experimental Study of the ^8He+p Elastic and Inelastic Scattering" Physics Letters. B316. 38-44 (1993)
[Publications] N.Fukunishi: "Neutron-Skin and Proton-Skin Formation in Exotic Nuclei far from Stability" Physical Review. C48. 1648-1655 (1993)
[Publications] K.Matsuta: "Fragment Polarization of ^<43>Ti in the ^<43>T+C Collision" Hyperfine Interactions. 78. 127-131 (1993)
[Publications] K.Matsuta: "Beta-NMR Detection of Beta-Emitting Fragment ^<43>Ti" Hyperfine Interactions. 78. 123-126 (1993)
[Publications] K.Matsuta: "Production of Unstable Nuclei far from the Stability Line -Its Scope and Limitations" Hyperfine Interactions. 78. 1219-1238 (1993)
[Publications] T.Murakami: "High-Spin Isomeric State in ^<144>Pm" Zeitschrift fur Physik. A345. 123-124 (1993)
[Publications] Y.Gono: "High-Spin Isomers and High-Spin Isomer Beams" Nuclear Physics. A557. 341c-346c (1993)
[Publications] A.Ferragut: "A New High-Spin Isomer in ^<145>Sm" Journal of the Physical Society of Japan. 62. 3343-3344 (1993)
[Publications] T.Kishida: "The Decay of ^<14>Be" RIKEN Accelerator Progress Report (1993). (to be published).
[Publications] K.H.Kim: "TDHF Calculation on Reactions of Unstable Nuclei" 素粒子論研究. (to be published).
[Publications] A.Muta: "Single Particle Potential far from Stability" 素粒子論研究. (to be published).
[Publications] M.Yokoyama: "Quadruple Giant Resonances in Nuclei with Neutron Skin" 素粒子論研究. (to be published).
[Publications] A.Ono: "Momentum Distribution of Fragments in Heavy Ion Reactions:Dependence on the Stochastic Collision Process" Physical Review. C47. 2652-2660 (1993)
[Publications] A.Ono: "Nucleon Flow and Fragment Flow in Heavy Ion Reactions" Physical Review. C48. 2946-2955 (1993)
[Publications] A.Wierling: "Antisymmetrization of a Mean Field Calculation of the T-Matrix" Zeitschrift fur Physik. (to be published).
[Publications] Y.Suzuki: "Fragmentation Cross Sections of He Isotopes and Neutron Correlations" Nuclear Physics. A567. 957-970 (1994)
[Publications] D.Baye: "Evidence for Halo in Quenching of ^6He β Decay into α and Deuteron" Progress of Theoretical Physics. 91. 271-286 (1994)
[Publications] Y.Ogawa: "Momentum Distributions of ^9Li Fragment Arising from (^<11>Li,^9Li) Reaction and Neutron Correlations" Nuclear Physics. (to be published).
[Publications] K.Varga: "Microscopic Multicluster Description of Neutron-Halo Nuclei with a Stochastic Variational Method" Nuclear Physics. (to be published).

1993 Fiscal Year Annual Research Report

極端状況下の原子核の構造と相互作用

Principal Investigator

石原 正泰 東京大学, 大学院・理学系研究科, 教授 (40013396)

Research Products

[Publications] H.Sagawa: "Gamow-Teller States in Light Nuclei near the Neutron Drip Line" Physics Letters. B303. 215-219 (1993)

[Publications] T.Nomura: "Study of α Decays Following ^<40>Ar Bombardment on ^<238>U" Proceedings of RIKEN International Workshop on Heavy-Ion Reactions with Neutron-Rich Beams. (to be published).

[Publications] T.Fukuda: "Heavy Ion Fusion with Neutron-Rich Beams" Proceedings of RIKEN International Workshop on Heavy-Ion Reactions with Neutron-Rich Beams. (to be published).

[Publications] T.Nomura: "Study of α Decays Following ^<40>Ar Bombardment on ^<238>U" RIKEN Accelerator Progress Report (1993). (to be published).

[Publications] A.Yoshida: "Measurement of the Fusion Cross Section of ^<27>Al+^<197>Au using MWPC and Multi-target System" RIKEN Accelerator Progress Report (1993). (to be published).

[Publications] S.Hirenzaki: "Proton Elastic Scattering with ^9Li and ^<11>Li and its Halo Structure" Nuclear Physics. A552. 57-65 (1993)

[Publications] I.Tanihata: "Radioactive Beam Facilities and Their Physics Program" Nuclear Physics. A553. 361-372 (1993)

[Publications] B.M.Young: "Strong Isomer Production in Fragmentation Reactions" Physics Letters. B311. 22-26 (1993)

[Publications] D.Hirata: "Systematic Study of Sr Isotopes in the Relativistic Mean Field Theory" Physics Letters. B314. 168-172 (1993)

[Publications] A.A.Korsheninnkov: "Experimental Study of the ^8He+p Elastic and Inelastic Scattering" Physics Letters. B316. 38-44 (1993)

[Publications] N.Fukunishi: "Neutron-Skin and Proton-Skin Formation in Exotic Nuclei far from Stability" Physical Review. C48. 1648-1655 (1993)

[Publications] K.Matsuta: "Fragment Polarization of ^<43>Ti in the ^<43>T+C Collision" Hyperfine Interactions. 78. 127-131 (1993)

[Publications] K.Matsuta: "Beta-NMR Detection of Beta-Emitting Fragment ^<43>Ti" Hyperfine Interactions. 78. 123-126 (1993)

[Publications] K.Matsuta: "Production of Unstable Nuclei far from the Stability Line -Its Scope and Limitations" Hyperfine Interactions. 78. 1219-1238 (1993)

[Publications] T.Murakami: "High-Spin Isomeric State in ^<144>Pm" Zeitschrift fur Physik. A345. 123-124 (1993)

[Publications] Y.Gono: "High-Spin Isomers and High-Spin Isomer Beams" Nuclear Physics. A557. 341c-346c (1993)

[Publications] A.Ferragut: "A New High-Spin Isomer in ^<145>Sm" Journal of the Physical Society of Japan. 62. 3343-3344 (1993)

[Publications] T.Kishida: "The Decay of ^<14>Be" RIKEN Accelerator Progress Report (1993). (to be published).

[Publications] K.H.Kim: "TDHF Calculation on Reactions of Unstable Nuclei" 素粒子論研究. (to be published).

[Publications] A.Muta: "Single Particle Potential far from Stability" 素粒子論研究. (to be published).

[Publications] M.Yokoyama: "Quadruple Giant Resonances in Nuclei with Neutron Skin" 素粒子論研究. (to be published).

[Publications] A.Ono: "Momentum Distribution of Fragments in Heavy Ion Reactions:Dependence on the Stochastic Collision Process" Physical Review. C47. 2652-2660 (1993)

[Publications] A.Ono: "Nucleon Flow and Fragment Flow in Heavy Ion Reactions" Physical Review. C48. 2946-2955 (1993)

[Publications] A.Wierling: "Antisymmetrization of a Mean Field Calculation of the T-Matrix" Zeitschrift fur Physik. (to be published).

[Publications] Y.Suzuki: "Fragmentation Cross Sections of He Isotopes and Neutron Correlations" Nuclear Physics. A567. 957-970 (1994)

[Publications] D.Baye: "Evidence for Halo in Quenching of ^6He β Decay into α and Deuteron" Progress of Theoretical Physics. 91. 271-286 (1994)

[Publications] Y.Ogawa: "Momentum Distributions of ^9Li Fragment Arising from (^<11>Li,^9Li) Reaction and Neutron Correlations" Nuclear Physics. (to be published).

[Publications] K.Varga: "Microscopic Multicluster Description of Neutron-Halo Nuclei with a Stochastic Variational Method" Nuclear Physics. (to be published).

石原正泰東京大学, 大学院・理学系研究科, 教授 (40013396)