Problems in estimating average degree of ionization for high-temperature dense plasmas

The average degree of ionization $Z^{*}$ for a high-density plasma is examined in Thomas-Fermi and Debye-Huckel-Thomas-Fermi statistical models. To clarify ambiguities in defining $Z^{*}$, predictions from several versions of these models are compared for the case of a pure hydrogen plasma for ion number density $N_1={10}^{23}$ ${\mathrm{cm}}^{-3\mathrm{}}$, at $kT=1-1000\mathrm{}$ eV. The results offer some insight regarding the validity of the statistical models.