用于自发裂变反应的带投影的精确含时生成坐标法
An exact time-dependent generator coordinate method with projection for spontaneous fission reactions
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中文总结 AI 辅助
本研究开发了带投影的精确含时生成坐标法，用于减少经验输入的自发裂变微观描述，为改进相关预测提供了途径。
中文摘要 AI 辅助
对穿过势垒的裂变动力学的微观描述依赖于不同裂变机制下的不同理论框架，含时生成坐标法（TDGCM）通常用于诱发裂变，而诸如温策尔-克拉默斯-布里渊（WKB）方法之类的半经典方法则广泛用于自发裂变。在本工作中，我们基于TDGCM的精确公式开发了一种用于自发裂变的全微观方法，避免了高斯重叠近似和半经典处理。通过将精确TDGCM与新的投影工具以及自发裂变的准静态描述相结合，我们从一维势能面推导出自发裂变寿命。对模型参数的详细分析表明，它们不会引入不受控的唯象效应。与实验寿命的剩余差异可追溯到潜在微观相互作用的可能限制以及生成坐标法中基态的选择。新框架提供了具有更少经验输入的自发裂变微观描述，并为通过未来核相互作用、集体坐标及多体动力学处理的发展实现改进预测提供了途径。
英文摘要
Microscopic descriptions of fission dynamics through the barrier rely on different theoretical frameworks depending on the fission regime, with the time-dependent generator coordinate method (TDGCM) commonly used for induced fission and semiclassical approaches such as the Wentzel-Kramers-Brillouin (WKB) method widely employed for spontaneous fission. In this work, we develop a fully microscopic approach to spontaneous fission based on an exact formulation of the TDGCM, avoiding both the Gaussian overlap approximation and semiclassical treatments. By combining the exact TDGCM with new projection tools and a quasistatic description of spontaneous fission, we derive spontaneous fission lifetimes from a one-dimensional potential energy surface. A detailed analysis of the model parameters shows that they do not introduce uncontrolled phenomenological effects. Remaining discrepancies with experimental lifetimes are traced to possible limitations of the underlying microscopic interaction and to the choice of basis states in the generator coordinate method. The new framework provides a microscopic description of spontaneous fission with reduced empirical input and offers a pathway toward improved predictions through future developments of nuclear interactions, collective coordinates, and the handling of many-body dynamics.
