Fluid hydrogen at high density - Pressure dissociation

摘要: In an earlier paper [Phys. Rev. A 44, 5122 (1991)], we presented a Helmholtz-free-energy model for nonideal mixtures of hydrogen atoms and molecules. the present paper, extend this to describe interacting mixture ${\mathrm{H}}_{2}$, H, ${\mathrm{H}}^{+}$, ${\mathit{e}}^{\mathrm{\ensuremath{-}}}$ in chemical equilibrium. This general describes phenomena dissociation ionization caused by pressure temperature effects, as encountered astrophysical situations high-pressure experiments. The is thermodynamically unstable pressure-ionization regime predicts existence plasma phase transition with critical point at ${\mathit{T}}_{\mathit{c}}$=15 300 K, ${\mathit{P}}_{\mathit{c}}$=0.614 Mbar, ${\mathrm{\ensuremath{\rho}}}_{\mathit{c}}$=0.35 g/${\mathrm{cm}}^{3}$. occurs between weakly ionized partially (\ensuremath{\approxeq}50%) phase. Molecular occur same narrow density range; play minor role ionization. high-density phase, complete reached gradually. sensitivity coexistence curve parameters assumptions discussed detail.