Study of new reaction mechanisms for the synthesis of heavy and superheavy nuclei

重核和超重核合成新反应机理研究

• 批准号: 398587408
• 负责人: Dr. H.M. Devaraja
• 金额: --
• 依托单位: II. Physikalisches Institut
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/398587408?language=en
• 关键词: Study; new; reaction; mechanisms; synthesis

Exotic nuclei are usually produced by projectile fragmentation or projectile fission at relativistic energies or in complete fusion reactions at Coulomb barrier energies. These production methods and the available beam intensities determine the present boarders of the chart of nuclides. A possible way to expand into unknown territory might be multi-nucleon transfer (MNT) reactions. They allow, in principle, to produce neutron-rich as well as neutron-deficient isotopes with proton numbers reaching far beyond uranium. This option has become a topical subject in various laboratories around the world. Appropriate separation and detection techniques are being developed as well as the theoretical framework.In our recent work, we have succeeded in producing and identifying several new neutron-deficient transuranium isotopes produced in MNT reactions of 48Ca + 248Cm using the velocity filter SHIP at GSI. This experimental method turned out to be very sensitive for the detection of heavy target-like transfer products which are emitted in forward direction and allowed us to reach limit cross-sections two orders of magnitude lower than in previous experiments.Our investigations represent pioneering work which is still at the beginning and needs further experimental and theoretical elaboration. Ongoing and future investigations include the continuation of data analysis of the existing data and new experiments at different beam energies. Special focus will be put on the search for further new isotopes in existing and future data, the population of reaction products above the target and on the possible population of neutron-rich isotopes below Pb, along the N = 126 shell. The study also includes the investigation of acceptance and transport properties of the existing velocity filters for MNT products in order to optimize the separator settings in future experiments and for the design of a possible next-generation velocity filter.

奇异核通常是由相对论能量下的射弹碎裂或射弹裂变或库仑势垒能量下的完全聚变反应产生的。这些生产方法和现有的束流强度决定了目前核素图的边界。一种可能的方法扩展到未知的领域可能是多核子转移（MNT）反应。原则上，它们可以产生质子数远远超过铀的富中子和缺中子同位素。这一选择已成为世界各地各实验室的热门课题。在我们最近的工作中，我们已经成功地利用GSI的速度过滤器SHIP产生和鉴定了几种新的缺中子超铀元素同位素。这种实验方法被证明是非常敏感的检测重靶状的传输产品是在向前的方向发射，并允许我们达到极限截面两个数量级低于在以前的experiments.Our调查代表开创性的工作，这仍然是在开始，需要进一步的实验和理论阐述。正在进行的和未来的研究包括继续对现有数据进行数据分析，以及在不同束流能量下进行新的实验。特别重点将放在寻找更多的新同位素在现有的和未来的数据，人口的反应产物以上的目标和人口的可能的富中子同位素低于铅，沿着N = 126壳。该研究还包括调查现有的速度过滤器的MNT产品的接受和运输性能，以优化分离器设置在未来的实验和可能的下一代速度过滤器的设计。