Quasiclassical theory for wings of hydrogen spectral lines

A theory is derived for the wings on the hydrogen spectral lines in the approximation of binary collisions and in the quasiclassical approximation. This theory takes into account the interaction between the radiating atom and the perturbing particles in all orders of perturbation theory. The quadrupole interaction and the quadratic Stark effect are taken into account in addition to the linear Stark effect. Good agreement in terms of both the intensity and the asymmetry is found between the calculated profiles of the L/sub α/ line and the experimental data available for frequency differences Vertical BarΔωVertical Bar> or approx. =2√2ω/sub e/ where ω/sub e/ is the electron plasma frequency. This agreement suggests that the range of applicability of the quasiclassical approximation is greater than has been generally assumed. Comparison of the present calculations with other theories shows that the present results should be used for wing calculations