Eur. Phys. J. D 23, 265-272 (2003)
https://doi.org/10.1140/epjd/e2003-00041-9

Thermodynamics of ionization and dissociation in hydrogen plasmas including fluctuations and magnetic fields

Institut für Physik, Humboldt-Universität zu Berlin, Invalidenstr. 110, 10115 Berlin, Germany

Corresponding authors: ^a ebeling@physik.hu-berlin.de - ^b hache@physik.hu-berlin.de - ^c spahn@physik.hu-berlin.de

Received: 10 September 2002
Revised: 26 November 2002
Published online: 11 February 2003

Abstract

Applying Gibb's geometrical methods to the thermodynamics of H-plasmas we explore the landscape of the free energy as a function of the degrees of ionization and dissociation. Several approximations for the free energy are discussed. We show that in the region of partial ionization/dissociation the quantum Debye-Hückel approximation (QDHA) yields a rather good but still simple representation which allows to include magnetic field and fluctuation effects. By using relations of Onsager-Landau-type the probability of fluctuations and ionization/dissociation processes are described. We show that the degrees of ionization/dissociation are probabilistic quantities which are subject to a relatively large dispersion. Magnetic field effects are studied.