Spontaneous generation of toroidal currents

A loss-cone mechanism for self-generation of toroidal currents is examined in toroidal magnetic configurations with a mirror-like vertical (poloidal) field. The loss cone is found to be asymmetric with respect to the toroidal velocity. Particles that carry a negative toroidal current are better confined than those that carry a positive current, giving rise to a net toroidal current that can be sufficiently large to close magnetic surfaces. This mechanism is found to be dependent on the curvature drift of particles, indicating that a low-aspect-ratio toroidal configuration is more favorable for this type of current generation