The Problem of Coronal Heating

The inhomogeneous coronal plasma is a perfect environment for fast growing drift waves. The omnipresence of coronal magnetic loops implies gradients of the equilibrium plasma quantities like the density, magnetic field and temperature. These gradients are responsible for the excitation of drift waves that grow both within the two‐component fluid description (both in the presence of collisions and without it) and within the two‐component kinetic descriptions (due to purely kinetic effects). Some aspects of these phenomena are investigated here. In particular the analysis of the particle dynamics within the growing wave is compared with the corresponding fluid analysis. While both of them predict the stochastic heating, the threshold for the heating obtained from the single particle analysis is higher. The explanation for this effect is given. Also, the effects of the density gradient in the direction perpendicular to the magnetic field vector are investigated within the kinetic theory, in both electrostati...