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

复核相互作用势的研究为我们在核结构和反应机理方面提供了丰富的信息。我们通过测量不稳定原子核束引起的弹性和非弹性截面，开辟了与不稳定原子核有关的相互作用势的系统研究。我们设计并建造了一个新的设施“二次光束线”，它可以输送不稳定的核光束。该设施将与大阪大学核物理研究中心新回旋加速器的高能重离子束一起使用。我们的二次光束线利用了物质中离子能量损失的A-和Z-依赖（能量衰减器）。并使我们能够得到二次束形式的反应产物。通过将降解剂视为离子光学元件之一，对分离器进行了离子光学考虑。通过这种新的处理方法，可以根据实验要求优化系统的光学性能。我们研究了两种方法：(1)实现二次光束的消色差聚焦；(2)获得能量扩散小的光束。基于设计研究。二次梁线已于1992年底建成。1992年2月，用300 MeV的阿尔法束流成功地测试了束流线的性能。新的回旋加速器仍在为光离子束进行调试。虽然我们的实验中不可避免的重离子束还没有加速。它们有望在1993年初夏注入我们的束流线。构建了一个具有大立体角、高能量和位置分辨率的探测器系统。探测器系统由12个条带位置敏感的Si-DELTAW探测器和CsI(TI)-E探测器组成。紧凑的预放大系统也被设计用来处理来自探测器系统的大量信号；放大器的数量通常是50个。该探测器系统在低能重离子束在线测试中表现出满意的性能。总而言之，我们已经构造了二次束流线，用以计算不稳定原子核的束流。我们准备研究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