重离子核反应中超重核生成截面的研究
发布时间：2019-03-23 19:49
【摘要】：近年来,超重核合成的研究已经成为核物理研究的重要领域之一。本文对超重核的生成截面进行了理论计算和研究,可分为以下三个部分。第一部分:首先,计算了若干反应道的俘获截面。其次,我们采用求解主方程而不对驱动势做任何近似来描述弹靶核之间的核子转移过程,计算了形成超重复合核的熔合几率,结果显示熔合几率随入射能量增加而增大。此外,采用统计模型计算了超重复合核的存活几率。最后,给出了若干反应道的蒸发剩余截面。第二部分:在双核模型的框架内,研究了超重核生成截面分别对弹核同位素链与靶核同位素链的同位素依赖性。结果显示超重核的生成截面对弹核同位素链与靶核同位素链都有强烈的同位素依赖性,且弹核越丰中子、生成截面越小,而靶核越丰中子、生成截面越大。造成超重核生成截面同位素依赖性的重要因素包含内熔合位垒、裂变位垒、及中子分离能等。第三部分:在双核模型的框架内,对大质量转移反应进行了研究,计算了反应体系~(238)U+248Cm与~(238)U+~(238)U的驱动势。此外,我们计算了这两个反应体系的类靶核碎块分别在角动量L=0与L=40时不同时刻的质量产物分布。
[Abstract]:In recent years, the study of overweight nuclear synthesis has become one of the important fields of nuclear physics. In this paper, the generation cross section of superheavy nuclei is calculated and studied theoretically, which can be divided into the following three parts. The first part: firstly, the capture cross sections of several reaction channels are calculated. Secondly, we use the solution of the master equation without any approximation to the driving potential to describe the nucleon transfer process between the projectile and target nuclei, and calculate the fusion probability of the formation of overweight compound nuclei. The results show that the fusion probability increases with the increase of incident energy. In addition, the survival probability of the hyperrepetitive nucleus is calculated by using the statistical model. Finally, the evaporation residual cross sections of several reaction channels are given. The second part: in the framework of the binuclear model, the isotope dependence of the superheavy nucleus generation cross section on the isospin chain and the target isospin chain of the projectile nucleus is studied respectively. The results show that the formation cross section of the superheavy nucleus is strongly isotope dependent on the isospin chain of the projectile nucleus and the isospin chain of the target nucleus, and the more neutron-rich the projectile nucleus is, the smaller the cross-section of the formation is, while the larger the neutron-rich cross-section of the target nucleus is, the greater the formation cross-section is. The important factors contributing to isotope dependence of superheavy nuclei include internal fusion barrier fission barrier neutron separation energy and so on. Part three: in the framework of the binuclear model, the mass transfer reaction is studied, and the driving potentials of the reaction system ~ (238) U-248Cm and ~ (238) U ~ (238) U are calculated. In addition, we have calculated the mass product distributions of the target-like nuclear fragments of these two reaction systems at different times when the angular momentum is L _ (0) and L ~ (40), respectively.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O571
本文编号：2446168
[Abstract]:In recent years, the study of overweight nuclear synthesis has become one of the important fields of nuclear physics. In this paper, the generation cross section of superheavy nuclei is calculated and studied theoretically, which can be divided into the following three parts. The first part: firstly, the capture cross sections of several reaction channels are calculated. Secondly, we use the solution of the master equation without any approximation to the driving potential to describe the nucleon transfer process between the projectile and target nuclei, and calculate the fusion probability of the formation of overweight compound nuclei. The results show that the fusion probability increases with the increase of incident energy. In addition, the survival probability of the hyperrepetitive nucleus is calculated by using the statistical model. Finally, the evaporation residual cross sections of several reaction channels are given. The second part: in the framework of the binuclear model, the isotope dependence of the superheavy nucleus generation cross section on the isospin chain and the target isospin chain of the projectile nucleus is studied respectively. The results show that the formation cross section of the superheavy nucleus is strongly isotope dependent on the isospin chain of the projectile nucleus and the isospin chain of the target nucleus, and the more neutron-rich the projectile nucleus is, the smaller the cross-section of the formation is, while the larger the neutron-rich cross-section of the target nucleus is, the greater the formation cross-section is. The important factors contributing to isotope dependence of superheavy nuclei include internal fusion barrier fission barrier neutron separation energy and so on. Part three: in the framework of the binuclear model, the mass transfer reaction is studied, and the driving potentials of the reaction system ~ (238) U-248Cm and ~ (238) U ~ (238) U are calculated. In addition, we have calculated the mass product distributions of the target-like nuclear fragments of these two reaction systems at different times when the angular momentum is L _ (0) and L ~ (40), respectively.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O571
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相关期刊论文 前3条
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