Theory of the Runaway Electron Tail

The steady-state electron distribution function of a current-carrying magnetized plasma is determined self-consistenly with the enhanced $\omega =\frac{{\omega }_{\mathrm{pe}}{k}_{\parallel }}{k}$ plasma wave spectrum it generates. Consequences include enhanced fluctuations at $\omega \simeq {\omega }_{\mathrm{pe}}$ and energy transport by $\omega <{\omega }_{\mathrm{pe}}$ waves which is found to be greater than that by neoclassical ion thermal conduction and of the order of the observed transport in intermediate-density tokamaks.