Guiding-centre motion in the framework of Hamilton-Jacobi theory

Following renewed interest in the guiding-centre problem, we propose an alternative to previous approaches. It consists essentially in demonstrating the existence of a representative simple model for which the problem is rigorously solved in the Hamilton-Jacobi framework. It is shown that a perturbation method allows the extension of the model to more realistic cases. A further extension to cover both magnetic-mirror configurations and tokamaks can be achieved.