Production of and Physics with High-Intensity Radioactive Nuclear Beam

本研究的主要目的是开发各种技术来实现加速放射性核束(RNB)，目前预计这种技术将开辟核物理和相关科学的新领域。利用不稳定核束开展一些开创性的实验，展示其作为一种新的实验工具的威力，是本工作的另一个目的。以下对象是在本研究开始时设立的，并与欧洲、加拿大和美国的几所大学和机构的研究人员合作成功地完成了这些实验，如瑞士的CERN、加拿大的TRIUMF和德国的吉森大学。这些结果已在1992年至1993年举行的几次国际核物理会议上发表，并发表在国际科学期刊上。a.用于在线同位素分离器(ISOL)的高效离子源的研究和开发-ISOL离子源，如表面离子…的离子源与INS、CERN和TRIUMF合作，开发了更多适合厚靶使用的熔化、等离子体和ECR类型。一些元素的电离效率高达几十%。B.设计了高质量分辨率的ISOL光学元件-设计了由磁级和静电级组成的ISO光学元件，并通过蒙特卡罗模拟证明其质量分辨率超过20000。这是与INS、东北大学和吉森大学合作完成的。c.放射性核束的加速-一种特殊类型的重离子直线加速器，称为分裂同轴RFQ，在INS和GSI(德国)进行了研究。这种类型的加速器已经在INS上建成，它可以成功地加速极小荷质比的低速重离子。它使放射性核束能够有效地加速。D.利用RNB进行核和核天体物理的开创性实验-通过与京都大学和欧洲核子研究中心等合作，通过光泵成功地实现了注入固体中的不稳定核的自旋极化。研究宇宙中重元素合成的核天体物理实验也在里肯、INS和法国甘尼勒进行，正在进行中。较少

The main purpose of the present study is to develop various techniques to realize accelerated radioactive nuclear beams (RNB) that are presently expected worldwide to open new fields of nuclear physics and related sciences. To carry out some pioneering experiments by use of the unstable nuclear beams to show their powerfulness as a new experimental tool is another aim of this work.The following objects were set up in the beginning of the present study and were successfully carried out in collaboration with researchers of several universities and institutions in Europe, Canada and U. S. A. such as CERN (The Switzerland), TRIUMF (Canada) and University of Giessen (Germany). The results have been presented in several international conferences on nuclear physics held in 1992-93 and have also been published in international scientific journals.A. Research and development of highly efficient ion sources for an isotope separator on-line (ISOL)--- ISOL ion sources such as those of surface-ioni … More zation, plasma and ECR types suited for the use of thick targets have been developed in collaboration with INS, CERN and TRIUMF. High ionization efficiencies up to several tens of % were achieved for some elements.B. Detailed design of the high-mass resolving-power ISOL optics--- The ISOL consisting of both magnetic and electrostatic stages have been designed and shown to realize a mass resolving power over 20, 000 by the MonteCarlo simulations. This has been done in collaboration with INS, Tohoku and Giessen Unversites.C. Accelration of radioactive nuclear beams--- A special type of heavy-ion linac, called a split-coaxial RFQ, has been studied in INS and GSI (germany). A prototype accelerator of this type has been constructed at INS, which could successfully accelerate low-speed heavy ions with extremely small charge-to-mass ratios. It has enabled efficient acceleration of radioactive nuclear beams.D. Pioneering experiments on nuclear and nuclear astrophysics with RNB--- The spin polarization of unstable nuclei implanted into solids has successfully been achieved, in collaboration with Kyoto University and CERN, etc., by optical pumping. Nuclear astrophysical experiments to study heavy-element synthesis in the universe were also carried out in RIKEN, INS and are in progress at GANIL (France). Less