基于协变能量密度泛函的^(250)Cf诱发裂变动力学研究

Microscopic Study of Induced Fission Dynamics of ^(250)Cf with Covariant Energy Density Functionals

在基于相对论能量密度泛函的自洽框架下,分析了^(250)Cf低能诱发裂变的动力学过程。基于能量密度泛函PC-PK1和δ对力,在轴对称四极和八极形变的集体空间中进行了含约束的相对论平均场计算,以确定裂变核的位能面、剪裂线、单核子波函数、能量以及轨道占据几率。在高斯重叠近似下,用含时生成坐标方法描述了诱发裂变动力学。将裂变过程描述为完全由微观单核子自由度决定的集体薛定谔方程在时间上绝热传播,通过将集体哈密顿量的第一个本征态进行激发建立初态。研究了^(250)Cf的集体波函数在四八极空间的含时演化,给出了诱发裂变下裂变碎片的质量分布。

Using the self consistent framework based on relativistic energy density functional,the dynamic process of ^(250)Cf low energy induced fission is analyzed.Based on energy density functional PC-PK1 andδ-force pairing,the constrained relativistic mean field is calculated in the collective space of axisymmetric quadrupole and octupole deformation to determine the potential energy surface,scission line,the single-nucleon wave function,energies and orbital occupation probability of the fission nucleus.Under the Gaussian overlap approximation,the time-dependent generation coordinate method is used to describe the induced fission dynamics.The fission process is described as the adiabatic propagation of the collective Schrodinger equation completely determined by the micro single nucleon degree of freedom in time.The initial state is established by exciting the first eigenstate of the collective Hamiltonian.The time-dependent evolution of ^(250)Cf collective wave function in quadrupole and octupole deformations space is studied,and the mass distribution of fission fragments under induced fission is given.