Scaling of hydrogen electron stark widths at high densities and theInglis–Teller limit

The density dependence of Stark widths at high densities can vary significantly and in a manner contrary to the well-known behavior at lower densities, reflecting issues such as the screening length, collisions, and non-impact effects. In this regime reversed temperature dependence as well as a weak density dependence is possible. At high densities effects such as continuum lowering and the Inglis–Teller limit, whose computation needs care, become important. Specifically the atomic wavefunctions involved may be: a) broadened mostly or significantly by electron collisions; b) such that practically all collisions are strong so that standard perturbative estimates do not work; or c) comparable to the screening length, so that the penetrating collisions are severely overestimated by the standard line broadening theory. Interesting possibilities are a width saturation, the experimental determination of the shielding length from the line widths and abnormal continuum lowering behavior.