Reference Distribution Functions for Magnetically Confined Plasmas from the Minimum Entropy Production Theorem and the MaxEnt Principle, subject to the Scale-Invariant Restrictions

TL;DR

This paper derives a reference distribution function for magnetically confined plasmas far from equilibrium using the minimum entropy production theorem and MaxEnt principle with scale invariance, linking it to plasma transport coefficients.

Contribution

It introduces a novel derivation of the plasma reference distribution function based on thermodynamic principles and stochastic processes, applicable to magnetically confined plasmas.

Findings

The reference distribution function is the stationary solution of a Landau-type stochastic process.

Application to ionized plasmas with Ohmic heating demonstrates the model's relevance.

Parameters are connected to plasma transport coefficients via kinetic theory.

Abstract

We derive the expression of the reference distribution function for magnetically confined plasmas far from the thermodynamic equilibrium. The local equilibrium state is fixed by imposing the minimum entropy production theorem and the maximum entropy (MaxEnt) principle, subject to scale invariance restrictions. After a short time, the plasma reaches a state close to the local equilibrium. This state is referred to as the reference state. The aim of this letter is to determine the reference distribution function (RDF) when the local equilibrium state is defined by the above mentioned principles. We prove that the RDF is the stationary solution of a generic family of stochastic processes corresponding to an universal Landau-type equation with white parametric noise. As an example of application, we consider a simple, fully ionized, magnetically confined plasmas, with auxiliary Ohmic heating. The free parameters are linked to the transport coefficients of the magnetically confined plasmas, by the kinetic theory.