On the kinetic and thermodynamic electron temperatures in non-thermal plasmas
1 Instituto de Ciencia de Materiales de Sevilla (CSIC-US) - Americo Vespucio 49, 41092 Seville, Spain
2 Departamento de Física Atómica, Molecular y Nuclear, Universidad de Sevilla - Avda. Reina Mercedes s/n, 41071 Seville, Spain
Received: 2 August 2013
Accepted: 23 December 2013
The framework to describe the out-of-equilibrium free electrons in cold plasmas is developed assuming the electron entropy is defined through the Boltzmann H-theorem. Our theory explains why the Saha-Boltzmann relation among higher-lying excited states by means of the electron kinetic temperature is fulfilled, even when free electrons are far from equilibrium. The thermodynamic electron temperature, pressure and chemical potential have been introduced through the derivatives of the electron entropy. It is demonstrated that under usual conditions in cold plasmas, e.g. when the electron distribution function possesses the Maxwellian, Druyvestein or Kappa functional forms, kinetic and thermodynamic electron temperatures yield the same value.
PACS: 52.25.Kn – Thermodynamics of plasmas / 52.20.-j – Elementary processes in plasmas / 34.80.Dp – Atomic excitation and ionization
© EPLA, 2013