Study of interaction potentials in reactions induced by nuclei far from the stability

复杂核相互作用势的研究为我们提供了丰富的核结构和反应机理的信息。我们通过测量不稳定核束引起的弹性和非弹性截面，对与不稳定核有关的相互作用势进行了系统的研究。我们已经设计并建造了一个新的设施“二次束线”，提供不稳定的核束。该设施将用于大坂大学核物理研究中心新回旋加速器的高能重离子束。我们的次级束线利用了物质中离子能量损失的A和Z依赖性（能量降能器）。并且使我们能够获得次级束形式的反应产物。通过将降能器视为离子光学元件之一，对分离器进行了离子光学考虑。通过这种新的处理，已经使得可以优化系统的光学器件， 关于我们 g实验要求。我们研究了实现次级光束消色差聚焦的方法和获得小能散光束的方法。基于设计研究。到1192财政年度末，已建成了次级电子束线路。1992年2月用300 MeV α束流成功地测试了束线的性能。新的回旋加速器仍在为轻离子束进行调整。虽然重离子束，这是不可避免的，我们的实验还没有被加速。可望在一九九三年夏初，将这些粒子注入我们的光束线。建立了一个大立体角、高能量和位置分辨率的探测器系统。探测器系统由12条位置敏感的Si-DELTAW探测器和CsI（TI）-E探测器组成。紧凑的前置放大系统也被设计为科普来自探测器系统的大量信号;放大器的数量通常为50个。该探测器系统在低能重离子束在线测试中表现出令人满意的性能。综上所述，我们已经建立了释放不稳定核束流的次级束线。我们准备研究由不稳定核束引起的弹性和非弹性散射。少

Study of interaction potentials between complex nuclei have brought us fruitful information on both nuclear structure and reaction mechanism. We have opened up a systematic study of the interaction potentials associated with unstable nuclei by measuring the elastic and inelastic cross sections induced by beams of unstable nuclei. We have designed and constructed a new facility "secondary-beam line" which delivers unstable nuclear beams. The facility is to be used with high energy heavy-ion beams from the new cyclotron at the Research Center for Nuclear Physics at Osaka University. Our secondary-beam line takes advantage of A- and Z- dependence of the energy loss of ions in matter (energy degrader). and enables us to obtain the reaction products in the form of a secondary beam. Ion-optical consideration has been made for the separator by treating the degrader as one of the ion-optical elements. By this new treatment it has been made possible to optimize the optics of the system accordin … More g to experimental requirements. We have investigated the methods (i) to achieve an achromatic focusing of the secondary beams and (ii) to obtain beams with small energy spread. Based on the design study. the secondary-beam line has been constructed by the end of FY1192. The performance of the beam line has been successfully tested with 300 MeV alpha beam in February 1992. the new cyclotron is still under tuning for light-ion beams. Although heavy-ion beams which are inevitable for our experiments have not yet been accelerated. they will be injected into our beam line hopefully in early summer of 1993. A detector system with large solid angle and high energy and position resolutions has been constructed. The detector system consists of 12 strip position sensitive Si-DELTAW detector and CsI(TI)-E detector. Compact pre-amplifies system has also been designed to cope with a large number of signals from the detector system; the number of the amplifies are 50 typically. The detector system showed satisfactory performance in an on-line test with low energy heavy-ion beams. In summary we have constructed the secondary-beam line which delibers beams of unstable nuclei. and we are ready to investigate the elastic and inelastic scatterings induced by unstable nuclear beams. Less