Ion thermal conductivity for a pure tokamak plasma

The neoclassical and Pfirsch--Schlueter components of the ion heat conduction for a pure hydrogen tokamak plasma are recalculated without assuming large aspect ratio and without neglecting energy scattering collisions. Using a model collision operator, the conductivity is determined numerically for various collision frequencies and aspect ratios. An approximate algebraic expression is fitted to the results. Even for comparatively large aspect ratios (approx.10) energy scattering increases the conductivity in the banana regime by about 50% and for small aspect ratios (approximately 3.3) the Pfirsch--Schlueter contribution causes a further increase of approximately 60%