Transport Properties of Equal Mass Plasma

Plasma physics

Abdul-Rassak, Saad Yousif

University:University of Glasgow

关键词: Plasma physics;   

Others  :  http://theses.gla.ac.uk/75208/1/13815365.pdf

来源: University of Glasgow

【 摘 要 】

In plasma physics studies, transport coefficients such as electrical and thermal conductivities, diffusion and viscosity are very important. In this thesis we have studied transport in the case of equal mass plasma (e.g. electron-positron plasma). In chapter one we present a general review of plasma physics including plasma production, criteria for definition of plasma, natural occurrence of the plasma state. In this chapter we describe kinetic theory, in particular the equations of Boltzmann, Fokker-Planck and Liouville, then introduce the concepts of transport theory. The use of irreversible thermodynamics to calculate the transport coefficients is presented in chapter two, in which we give an expression for the Gibbs equation as well as the equations for equal mass plasma in the centre of mass frame. The relaxation time method is presented, then we find equations for current, heat flux, particle flux and the stress tensor for equal mass plasma. From these equations we find the electrical and thermal conductivities, diffusion and viscosity coefficients In chapter three, kinetic theory is used to calculate plasma transport coefficients. The kinetic equation used to describe the system is Boltzmann. Temperatures and densities are assumed to be equal everywhere. We find the equations which describe the behaviour of the macroscopic variables such as density, mean velocity, pressure and temperature. Then frictional and thermal forces are found. In this chapter departure from an equilibrium is caused by a temperature gradient, presence of electric field and relative velocity between the two species. Expressions for transport coefficients for equal mass plasma are found. In chapter four, the results of chapter two and three are reviewed in various approximations. Because I have done this work in case of electron-positron plasma , where the masses of the two species are equal, it is not possible to use the approximation of neglecting the terms consisting the ratio of (me/mi) (Braginskii 1965 and Kaneko 1960). We cannot assumed the ions are at rest or the velocity of the electrons is much bigger than the velocity of the ions, so in my work I assumed every species has its own independent velocity. Hence this work is a repeat of existing work without its usual approximations.