尾流效应对快速双原子分子离子在固体中电荷态及分子轴取向的影响

Wake effects on charge states and molecular-axis orientations of fast diatomic molecular ions in solids

研究了快速双原子分子离子在固体中穿行时 ,尾流效应对各离子电荷态以及库仑爆炸过程的影响 .借助于线性介电响应理论和局域介电函数 ,离子之间的动力学相互作用势可以表示成对称的屏蔽库仑势和非对称的尾势 .通过对分子离子上所有束缚电子的总能量进行变分和求解单个离子的运动方程 ,自洽地确定出分子离子中每个离子的电荷态 .数值结果表明 ,由于尾流效应的影响 ,在初始穿行阶段 ,分子离子中导航离子的电荷数随穿行深度的增加而单调递增 ,而尾随离子的电荷数则随穿行深度的增加而振荡 .但当穿行深度很大时 ,两个离子的电荷数都趋于具有相同速度的孤立离子的电荷数 .此外 。

We have studied the wake effects on charge states and molecular-axis orientations of diatomic molecular ions, such as N-2(+), moving in solids. Based on the linear response dielectric theory with the local dielectric function, the dynamic interacting potential is expressed as a sum of the symmetric screened Coulomb potential and the asymmetric wake potential. The equilibrium charge state of individual ions in the molecular ions is determined by a variational approach to the total energy of bound electrons in the molecular ions. The Coulomb explosion patterns of the molecular ions are also simulated by solving equations of motion for individual ions. It has been found that, in the initial stages of penetration through the solid, the charge of the trailing ion oscillates with increasing penetration depth due to the wake effects in the dynamic interaction potential, while the charge of the leading ion increases monotonically towards the value characteristic of an isolated ion at the same speed. Moreover, the molecular-axis orientations incline towards the direction of the projectile's velocity.