Spin Resonances in Nuclei

目前的原子核自旋-自旋激发合作科学研究项目的目的是在RCNP（大阪大学核物理研究中心）和KVI（荷兰格罗宁根）的回旋加速器研究所研究“Nuelei中的自旋激发”。本财政年度，我们首次通过^<90>Zr (^3He, t)^<90>N波段^<71>Ga (^3He, t)^<71>Ge反应，在^3He轰击能量为450 MeV的情况下，测量了伽莫-泰勒共振的伽马衰变。这些研究对于提供太阳中微子探测的基础数据以及对原子核自旋激发的基本认识具有重要意义。这些数据对于理解双数据衰减也很重要。讨论了在AGOR回旋加速器和RCNP回旋加速器上研究等矢量单极子巨共振的实验方案。AGRO回旋加速器可以在1995年10月加速第一束。束流传输线路已经建立。磁谱仪已经准备好测量与衰变中子和质子相符合的（^3He, t）反应。我们进一步讨论了与“欧洲超新星”项目相关的合作工作，其中研究了原子核对中微子的吸收截面，以了解ii型超新星的爆炸机制。质子-质子和质子-核碰撞中的伽马辐射过程是本课题研究的课题之一。理论研究正在进行中。高能伽玛射线探测的实验装置大多在KVI完成。

The present project for the cooperative scientific ininvestigation of the spin-sisospin excitations in nuclei aims to study the "Spin Excitations in Nuelei" in both the cyclotron institutes at RCNP (Research Center for Nuclear Physics, Osaka University) and at KVI (Groningen, The Netherlands). This fiscal yaer, we have measured, for the first time, the gamma decay from the Gamow-Teller resonances via the ^<90>Zr (^3He, t)^<90>N band ^<71>Ga (^3He, t)^<71>Ge reactions at the ^3He bombarding energy of 450 MeV.These studies are important to give basic data for the solar neutrino detection as well as the basic understanding of the spin excitation in nuclei. The data are aslo important in uderstanding the double deta decay.The experimental program of investigation the isovector monopole giant resonaces are discussed in the AGOR cyclotron facility as well as in the RCNP facility. The AGRO cyclotron could accelerate the first beam in October 1995. The beam transport line has been established. The magnetic spectrometer is ready for the measurement of the (^3He, t) reactions in coincidence with decay neutrons and protons. We futhemore discuss the collaboration work accociated with the "EuroSuperNovae" project, in which the neutrino absorption cross-sections by nuclei are studied in order to understand the explosion mechanisms of typeII supermovae.The gamma emittion processes in the protonproton and proton-nucleus collisions are one of the syubjects to be studied in this project . Theoretical studies are in progress very much. The experimental setup for the detection of the high energy gamma rays are mostly finished at KVI.