Polarization of Balmer alpha radiation resulting from H⁺+H collisions in Debye plasmas

The linear polarization degree of Balmer alpha radiation resulting from $H++H(1s)$ collisions in a hot, dense weakly coupled plasma is studied in the energy range $1–140 keV/u$ by adopting the Debye-Hückel potential to represent the screened interaction between charged plasma particles. Due to the energy splitting of nl hydrogen states in the short range Debye-Huckel potential, the Balmer alpha radiation contains three components corresponding to 3s-2p, 3p-2s, and 3d-2p transitions, of which only the last two can be linearly polarized. For calculation of 3lm excitation and electron capture cross sections, the two-center expansion atomic orbital close coupling method is used for a number of Debye screening lengths. The effects of plasma screening on the 3lm cross sections are manifested in significant changes of their magnitudes and energy behavior with respect to the ones in the unscreened case, producing significant changes in the polarization degree of Balmer 3p-2s and 3d-2p lines.