Theoretical Treatment of Drift Waves in A Collisionless Plasma Regime within A Magnetically Confined Plasma

Abstract

The main objective of this study is to show that, the drift wave frequency and the radial distribution of the oscillating electric potential of a cylindrical magnetized plasma are influenced by the gradients in electron temperature, and the rotation. A theoretical model is introduced in this study which is based on two-fluid equations, for either electrons or ions and simplified to the collisionless magnetised plasma regime. In the present work, that the inclusion of electron temperature gradient is essential and must be taken into account in the theory. In addition, the plasma rotation which arises when a radial electric field exist in an axial magnetic field is included into a theoretical model. The effect of rotation will Doppler shift the drift wave frequency so that plasma rotates as a solid body. The radial plasma density and temperature profiles which are required as input to the theoretical calculation are also presented and displayed. The theoretical model predicts the actual frequency, and the radial fluctuation profiles of the mode and hence, the position of the maximum wave amplitude can be determined. We made a comparison of experimental measurement with the theoretical prediction for radial variation of eigen function of density fluctuation are also presented. The experimental data is obtained from an axial magnetised plasma of Zhang L. (1992) results. A matlap computer calculation is used for the differential equation for the radial distribution of the eigen function of density fluctuation. The results illustrates the importance of the effect of the electron-temperature and rotation Doppler shift into a theoretical model.