Abstract
This paper reviews the physical basis of existing equilibrium inert-gas shock-wave calculations and points out their limitations. The various solutions to the problems of terminating the electronic excitation partition function and also the lowering of the ionization potentials by a plasma microfield are discussed and coordinated into a family of cutoff procedures.New equilibrium shock-wave equations are derived which allow for multiple excitation and ionization and the presence of Debye–Huckel effects in the shock-heated plasma. It is demonstrated how the use of such a plasma model logically and simply provides a solution to the problem of energy-level cutoff.