论文标题
化合物核的裂变动力学：配对与波动
Fission Dynamics of Compound Nuclei: Pairing versus Fluctuations
论文作者
论文摘要
裂变可观察物的能量依赖性是广泛的核应用的关键问题。我们研究了在化合物核$^{240} $ pu中使用时间依赖的Hartree-fock+BCS方法的实时裂变动力学。结果表明，在有限温度下，裂变后期裂变的演化时间大大延长。由于动态配对的作用是在高激发时消失，因此费米表面周围的单粒子水平之间的随机过渡到模拟热波动是必不可少的。获得的裂变产率和具有波动的总动能可以分为两个不对称的分裂通道，即S1和S2，这解释了实验性的良好结果，并为Brosa模型提供了微观的支持。随着波动的增加，S2通道接管S1通道，并获得扩散裂变可观察物。
Energy dependence of fission observables is a key issue for wide nuclear applications. We studied real-time fission dynamics from low-energy to high excitations in the compound nucleus $^{240}$Pu with the time-dependent Hartree-Fock+BCS approach. It is shown that the evolution time of the later phase of fission towards scission is considerably lengthened at finite temperature. As the role of dynamical pairing is vanishing at high excitations, the random transition between single-particle levels around the Fermi surface to mimic thermal fluctuations is indispensable to drive fission. The obtained fission yields and total kinetic energies with fluctuations can be divided into two asymmetric scission channels, namely S1 and S2, which explain well experimental results, and give microscopic support to the Brosa model. With increasing fluctuations, S2 channel takes over S1 channel and the spreading fission observables are obtained.
