THE ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 63:661-684, 1987 March

       RELATIVISTIC FREE-FREE GAUNT FACTOR OF THE DENSE HIGH-TEMPERATURE
                                STELLAR PLASMA

              MASAYUKI NAKAGAWA, YASUHARU KOHYAMA, AND NAOKI ITOH

            Department of Physics, Sophia University, Tokyo, Japan

                                   ABSTRACT

        The free-free Gaunt factor of the dense high-temperature stellar
     plasma is calculated by using the accurate relativistic cross section
     and is compared with the Gaunt factor derived by using Sommerfeld's
     exact nonrelativistic cross section. A wide range of electron
     degeneracy is accurately taken into account.  Significant deviations
     from the nonrelativistic results are found for high-temperature
     cases. Results are presented in the form of extensive tables to
     facilitate applications.

     Subject headings: atomic processes - opacities - plasmas - relativity