Theoretical study of the scattering of unstable nuclei and the synthesis of superheavy elements

不稳定核散射与超重元素合成的理论研究

基本信息

批准号：
04640280
负责人：
TAKIGAWA Noboru
金额：
$ 1.02万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

项目摘要

This research project aimed at exploring characteristics of heavy-ion collisions induced by unstable nuclei, especially by halo nuclei, and at finding a new way to synthesize superheavy elements. The structure of unstable nuclei and quantum tunneling in multi-dimensional systems were also studied as closely related subjects. The main achievements are as follows. 1. We studied the effect of projectile berak-up on the heavy-ion fusion reactions induced by a halo nucleus, and showed that one can still expect a larger fusion cross section for a halo nucleus than for the other isotopes at energies below the Coulomb barrier, though the projectile break-up moderates the large enhancement of the fusion cross section suggested in one of our previous papers for the collisions of a halo nucleus. 2. We showed that the differential cross section of the elastic scattering in medium energy heavy-ion collisions has a steeper fall off at angles where the so called far-side component dominates if a halo nucleus is used as the projectile. 3. We studied multi-nucleon transfer neactions in deep inelastic heavy-ion collisions based on a transport theory, and found that much larger number of neutrons are exchanged than protons if a halo nucleus is used as the projectile. 4. We showed that the tranverse momentum distribution of the projectile fragments in medium energy heavy-ion collisions gets narrower by reflectiong the reaction mechanism. 5. We studied the effects of environments on the tunneling rate of a macroscoic variable, and showed the importahce of a mass renormalization in the cases, where the environments have slightly shorter time scale than that of the tunneling process. Also, we developed a method, the method of dynamical norm factor, to treat non adiabatic effects in macroscopic quantum tunneling, and demonstrated its numerical accuracy by a few model calculations. Using this method, we analyzed the fission of ^<234>U, and showed that the coupling to a nuclear intrins

该研究项目旨在探索不稳定核，尤其是halo nuclei引起的重离子碰撞的特征，并找到一种合成超重元件的新方法。还研究了多维系统中不稳定的核和量子隧穿的结构。主要成就如下。 1. We studied the effect of projectile berak-up on the heavy-ion fusion reactions induced by a halo nucleus, and showed that one can still expect a larger fusion cross section for a halo nucleus than for the other isotopes at energies below the Coulomb barrier, though the projectile break-up moderates the large enhancement of the fusion cross section suggested in one of our previous papers for the collisions of a halo nucleus. 2。我们表明，中等能量重离子碰撞中弹性散射的差分横截面在角度上倾斜较高，如果将晕核核用作弹丸，则所谓的远面成分占主导地位。 3。我们研究了基于运输理论的深度非弹性重型离子碰撞中的多核子转移导入，并发现如果将晕核核用作弹丸，则与质子相比，与质子交换大量中子。 4。我们表明，通过反射反应机理，中等能量重离子碰撞中弹丸碎片的旋转动量分布变得更窄。 5。我们研究了环境对宏观货币变量的隧道率的影响，并显示了在环境的时间尺度略短于隧道过程的情况下，质量重新归一化的导入。此外，我们开发了一种方法，即动态规范因子的方法，用于处理宏观量子隧道中非绝热效应，并通过一些模型计算证明了其数值精度。使用这种方法，我们分析了 ^<234> u的裂变，并表明耦合到核内含量