The pure Coulomb free-free Gaunt factors of the dense high-temperature carbon and oxygen plasmas are calculated by using the accurate relativistic cross section and are compared with the Gaunt factors derived by using Sommerfeld's exact nonrelativistic cross section. A wide range of electron degeneracy is accurately taken into account. Effects from resonances in the free electron density of states are not included. Dramatic deviations from the nonrelativistic results are found for high-temperature cases. Results are presented in the form of extensive tables to facilitate applications.
The Rosseland mean free-free Gaunt factor of the dense high-temperature stellar plasma is calculated, based on both the accurate relativistic cross section and Sommerfeld's exact nonrelativistic cross section. A wide range of electron degeneracy is accurately taken into account. Comparison of the resulting free-free opacity with the electron conduction opacity is made.
