A derivation of the gradient $(∇B)$ drift based on energy conservation Available to Purchase

We present some basic concepts used to analyze single-particle motion in plasma environments, including the guiding center approximation and simple guiding center drifts. We then use these concepts to derive what is known as the $∇B$ (“grad B” or “gradient”) drift in a new way. In contrast to the standard approach involving perturbation techniques, we instead use a simple energy conservation law that gives insight into the physical causes of the drift and into some general properties of particle motion in electric and magnetic fields. This is a demonstration of the usefulness of energy conservation in analyzing particle motion and provides a clear example of how charged particles gyrating in an electric field that is not curl free are energized.