Ion thermal conductivity for a pure tokamak plasma

The neoclassical and Pfirsch–Schlüter 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 (∼10) energy scattering increases the conductivity in the banana regime by about 50% and for small aspect ratios (approximately 3.3) the Pfirsch–Schlüter contribution causes a further increase of approximately 60%.