Quantum screening effects on dipole and quadrupole electron-impact excitation channels in dense high-temperature plasmas

Abstract

Screening effects on the dipole and quadrupole electron-impact excitation of hydrogenic ions in dense high-temperature plasmas are investigated using the effective pseudopotential model that takes into account both quantum-mechanical and plasma screening effects. The semiclassical impact parameter method is applied to the path of the projectile electron in order to visualize the electron-impact excitation probability as a function of the impact parameter, thermal de Broglie wavelength, Debye length, and projectile energy. The excitation probability is found to be significantly decreased with increasing quantum screening effects. It is found that the maximum position of the excitation probability is receded from the target nucleus with decreasing projectile energy. It is also found that the quantum screening effects on the dipole excitation process are almost identical to those on the quadrupole excitation process.