Dynamic plasma screening effects on semiclassical electron captures from hydrogenic ions by protons in weakly coupled plasmas

Abstract

Electron capture processes by protons from hydrogenic ions in dense plasmas, including dynamic screening effects, are investigated using the semiclassical version of the Bohr and Lindhard model with the straight-line trajectory method. The dynamic interaction potential and screened electron radius are obtained by considering the longitudinal component of the plasma dielectric function. The scaled semiclassical electron capture probability is obtained as a function of the impact parameter, Debye length, and projectile velocity. The plasma screening effects on the target system is known to be quite small, so that the plasma screening effects on the capture probability is mainly determined by the screened capture radius. The dynamic screening effect on the scaled semiclassical capture probability is found to be more significant for low projectile velocities. When the projectile velocity is smaller than the electron thermal velocity, the dynamic screening effect is weaker than the static screening effect. However, when the projectile velocity is greater than the electron thermal velocity, the dynamic screening effect leads to the static screening effect. The maximum position of the scaled capture probability approaches to the target nucleus as an increase of the projectile energy.