Transport properties of a toroidal plasma in a mixed collisionality regime

The transport coefficients are calculated for an axisymmetric toroidally confined plasma comprised of main ions in the banana regime and high-Z impurities in the Pfirsch–Schlüter regime. The ambipolar particle diffusion coefficient scales like the Pfirsch–Schlüter value for a collisional plasma. The main ion heat conductivity, however, equals its value in a low collision frequency (banana regime) plasma, thus exceeding the particle diffusion by the factor δ−3/2, where δ<1 is the inverse aspect ratio. A neoclassical current comparable to the banana regime bootstrap current flows in response to the electron and ion gradients.