Excitations of Isovector Monopole Resonance in Nuclei

原子核中等矢量单极子共振的激发

• 批准号: 07640426
• 负责人: TANAKA Masayoshi
• 金额: $ 1.47万
• 依托单位: Kobe Tokiwa Jr. College
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07640426/
• 关键词: Isovector Monopole; Giant Dipole Resonance; Spin Dipole Resonance; One particle one hole; Statistical model; Neutron decay; GSO counter; Grand Raiden; 1粒子1孔; 集団励起モード; アイソスカラー; アイソベクター; 巨大共鳴; 準弾性散乱; 圧縮運動; 星の進化

We searched for the Isovector giant resonance by means of a tripple coincidence method among decay neutrons, 430 keV gamma-rays from the first excited state of ^7Be and scattered ^7Be following the (^7Li, ^7Be) reaction on ^<12>C using a 65 AMev ^7Li beam from a Ring cyclotron at RCNP.Osaka University. For detection of 7Be scattered at 0 degrees the magnetic spectrograph, "Grand-Raiden" was used. For detection of 430 keV gamma-rays and decay neutrons a GS0-counter array composed of 22 counter segments and liquid neutron counter arrays composed of 48 segments were used. It was found that we could succeeded in observing neutron decays from the isovector non spin-flip (DELTAS=0) states separately from the isovector spin-flip (DELTAS=1) states for the first time. This will hopefully provide a delightfull direction toward the discovery of the Isovector Giant Monopole Resonance.

我们使用大坂大学RCNP环形回旋加速器的65 AMev ^7Li束，通过三重符合方法，在衰变中子、来自^7Be第一激发态的430 keV γ射线和^7 Be在^ C上发生（^7Li，^7Be）反应后散射的^7Be之间寻找等矢量巨共振<12>。为了检测在0度散射的7 Be，使用了磁谱仪“Grand-Raiden”。为了探测430 keV的γ射线和衰变中子，使用了由22个计数器段组成的GS 0计数器阵列和由48个段组成的液体中子计数器阵列。发现我们首次成功地观测到了等矢量非自旋翻转态（DELTAS=0）和等矢量自旋翻转态（DELTAS=1）的中子衰变。这将有望为等矢量巨单极共振的发现提供一个令人愉快的方向。

项目成果

中山信太郎他: "The (^7Li,^7Be) reaction as a Spin-Probe for Isovector Excitations" Nuclear Instruments & Methods, Elsevier Science. (印刷中).

Shintaro Nakayama 等人：“(^7Li,^7Be) 反应作为等矢量激发的自旋探针”核仪器与方法，Elsevier Science（出版中）。

S.Nakayama, K.Fushimi, H.Kohri, H.Akimune, I.Daito, H.Fujimura, Y.Fujita, M.Fujiwara, T.Inomata, K.Ishibashi, T.Iwawaki, N.Koori, K.Takahisa, A.Tamii, M.Tanaka, H.Toyokawa, and T.Yamagata: ""GSO-detector system, 'NYMPHS' for (^7Li, ^7Be-gamma) Reaction at

S.Nakayama、K.Fushimi、H.Kohri、H.Akimune、I.Daito、H.Fujimura、Y.Fujita、M.Fujiwara、T.Inomata、K.Ishibashi、T.Iwawaki、N.Koori、K.

S.Nakayama, K.Fushimi, H.Kohri, H.Akimune, I.Daito, H.Fujimura, Y.Fujita, M.Fujiwara, T.Inomata, K.Ishibashi, T.Iwawaki, N.Koori, K.Takahisa, A.Tamii, M.Tanaka, H.Toyokawa, and T.Yamagata: ""The (^7Li, ^7Be-gamma) Reaction as a Spin-Probe for Isovector Ex

S.Nakayama、K.Fushimi、H.Kohri、H.Akimune、I.Daito、H.Fujimura、Y.Fujita、M.Fujiwara、T.Inomata、K.Ishibashi、T.Iwawaki、N.Koori、K.