Journal of Statistical Physics

, Volume 60, Issue 5–6, pp 619–637

Ionization equilibrium in the electron-proton gas

  • N. Macris
  • Ph. A. Martin


Using Fefferman's analysis of the quantum electron-proton gas, we give a rigorous proof of ionization equilibrium in this system. Ionization equilibrium phases are obtained as low-density and low-temperature limits, letting the chemical potentialμ(T) approach the ground-state energy of the hydrogen atom as the temperatureT tends to zero. The rate of ionization is determined by the slope ofμ(T) atT=0 and is correctly given by the Saha formula. We also discuss a simpler model where a single quantum particle interacts with a classical gas of hard spheres.

Key words

Ionization equilibrium Saha formula Coulomb systems dilute gases 


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Copyright information

© Plenum Publishing Corporation 1990

Authors and Affiliations

  • N. Macris
    • 1
  • Ph. A. Martin
    • 1
  1. 1.Institut de Physique ThéoriqueEcole Polytechnique Fédérale de LausanneLausanneSwitzerland

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