Coulomb broadening of autoionization resonances

The influence of Coulomb scattering on the velocity distribution and on the spectral resonances in the radiative transitions to continuum is studied for ions in a low-temperature plasma. Coulomb interaction levels off the nonequilibrium distribution of the excited-ion velocities that is produced by autoionizing coherent light. This results in the appearance of distorted Fano resonances in the absorption and photoionization spectra. It is established that in a strongly noniosothermal plasma, with the electron temperature well above that of the ions, the role of ion interaction with plasma waves in broadening the autoionization Fano resonances sharply increases. 7 refs., 2 figs