Electron-Impact Broadening of Overlapping He I Lines Plasmas

This is the authors' abstract. We don't add key points for this paper.

The general impact theory of electron broadening, developed previously by Griem, Baranger, Kolb, and Oertel (G BKO), is extended in order to take into account the off-diagonal matrix elements necessary to treat the case of partially overlapping lines.The new time integrals arising in the theory have rigorously been evaluated. It follows a generalized and consistent treatment of overlapping lines for any degree of degeneracy. The "complete degeneracy case" (hydrogen) and the "isolated-line case" appear as limiting situations in our theoretical description. In order to describe the four possible kinds of second-order atomic transitions, we are led to generalize the A and B functions of G BKO. Properties of these new A (z₁,z₂) and B (z₁,z₂) functions are considered in detail.