X-UV REFRACTION IN DENSE-PLASMAS

In a dense and hot plasma the refractive index in the x-u.v, range is caused by free electrons as well as by bound electrons. The refractive index is calculated by the Kramer-Kronig relations using the total opacity of the medium including bound-bound, free-bound and free-free atomic transitions. A simple method is presented of calculation of the emission and absorption coefficients which are of central importance to the study of radiative transfer in a dense and hot material. The computer program using a screened hydrogenic model allows one to obtain in either LTE or NLTE, the values of these coefficients for an arbitrary material over a wide range of mass density and temperature. Applications are presented first to generate opacity and emissivity tables used by hydrocodes including radiative transfer and second to generate the index of refraction of dense media. These calculations can provide a modelling for experiments by allowing the study of the structure of plasmas created by laser deposition and the evolution through the heat conduction.