Possibility of constructing a far-ultraviolet laser utilizing transitions in multiply charged ions in an inhomogeneous plasma

Radiative characteristics of a laser plasma are considered. It is shown that a considerable proportion of the absorbed laser energy may be converted into resonance lines of multiply charged ions. Two methods for the utilization of resonance x-ray radiation in the population inversion in a two-component plasma are discussed. In one method, the resonance radiation of one component in the dense core of the plasma is used for selective resonance pumping of some level in the other component in the outer rare region. In the second method, the radiation of ions in the outer layer is used to photoionize ions in the inner core; this produces conditions analogous to those in a supercooled plasma and a population inversion is established. In all cases, the gain may be of the order of 10³ cm^–1.