  In this paper we partly solve the problem of existence of separators of a
magnetic field in plasma. We single out in plasma a 3-body with a boundary in
which the movement of plasma is of special kind which we call an (a-d)-motion.
We prove that if the body is the 3-annulus or the "fat" orientable surface with
two holes the magnetic field necessarily have a heteroclinic separator. The
statement of the problem and the suggested method for its solution lead to some
theoretical problems from Dynamical Systems Theory which are of interest of
their own.
