DYNAMIC PLASMA SCREENING EFFECTS ON SEMICLASSICAL ELECTRON CAPTURES FROM HYDROGENIC IONS BY PROTONS IN WEAKLY COUPLED PLASMAS

Electron capture processes by protons from hydrogenic ions in dense pl asmas, including dynamic screening effects, are investigated using the semiclassical version of the Bohr and Lindhard model with the straigh t-line trajectory method. The dynamic interaction potential and screen ed electron radius are obtained by considering the longitudinal compon ent of the plasma dielectric function. The scaled semiclassical electr on capture probability is obtained as a function of the impact paramet er, Debye length, and projectile velocity. The plasma screening effect s on the target system is known to be quite small, so that the plasma screening effects on the capture probability is mainly determined by t he 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 th an the electron thermal velocity, the dynamic screening effect is weak er than the static screening effect. However, when the projectile velo city is greater than the electron thermal velocity, the dynamic screen ing 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. (C) 1998 American Institute of P hysics. [S1070-664X(98)00110-4].