Energy spectrum of hydrogen atoms in dense plasmas.

Abstract

From the Bethe-Salpeter equation for the two-particle (proton-electron) Green function, an effective Schr\"odinger wave equation can be derived for a hydrogen atom in a hydrogen plasma, which describes the perturbation of atomic energy levels and eigenstates by many-particle plasma effects (Pauli blocking, exchange and dynamic self-energy, and interaction-potential correction due to dynamic screening). Taking full account of dynamic screening by the random-phase approximation dielectric function, we solved the effective wave equation for nondegenerate plasmas. For bound atomic states, the plasma effects nearly compensate one another and the energy levels depend only weakly on density. In contrast, the lowering of the continuum edge is not diminished by such compensation, so that the bound states successively merge into the continuum with increasing plasma density. As our results show, reliable calculations have to incorporate dynamic screening, since the use of static screening (which greatly facilitates calculations) may lead to substantial errors, even at low densities.