Dynamic screening effects on antiscreening excitations for ion–ion collisions in dense plasma

Abstract

In dense plasmas, dynamic plasma screening effects are investigated on antiscreening channels for excitation of a one-electron ion target by a one-electron ion projectile. The ion–ion interaction potential is considered by the introduction of the longitudinal plasma dielectric function. A semiclassical straight-line trajectory method is applied to the ion projectile path in order to visualize the dynamic plasma screening effects on the transition probabilities in dense plasmas as a function of the impact parameter and the collision energy. The transition probabilities including the dynamic plasma screening effects are found to always be greater than those including the static plasma screening effects. When the projectile velocity is greater than the electron thermal velocity, the interaction potential is almost unshielded. The difference between the dynamic and static plasma screening effects is more significant for low-energy projectiles. It is also found that the quadrupole transitions (dipole-quadrupole and quadrupole–quadrupole) show the double peaks due to the node of the 2s radial wave function.