Transport Coefficients of Inhomogeneous Plasmas in a Magnetic Field

Transport coefficients of inhomogeneous, magnetized plasmas are derived using the quasilinear approximation. It is shown that mechanisms which allow the motion of ions across the magnetic field, such as ion-neutral collisions, are essential in arriving at divergent-free, finite transport coefficients in unbounded plasmas. The transport coefficients are calculated for both unbounded and bounded plasmas. Although in toroidal plasmas the transport coefficients do not follow the 1/B law, the calculated diffusion coefficients are numerically very close to what is known as the Bohm diffusion coefficients in a number of experimental devices.