Curvature & Gradient Drifts

Charge-dependent drifts from field curvature and gradients that must be cancelled to confine.

Field-line curvature and magnetic-field gradients cause ions and electrons to drift in opposite directions, which would separate charge and destroy confinement in a straight field. The tokamak's twist and the mirror's shaping cancel these drifts.

Curvature and gradient drifts push ions and electrons in opposite directions, which in a straight field would separate charge and destroy confinement — the very problem the tokamak's twisted field and the mirror's shaping exist to cancel. Understanding them is understanding why closed, rotationally-transformed field lines are necessary.