  We consider a 1 1/2degrees of freedom Hamiltonian dynamical system, which
models the chaotic dynamics of charged test-particles in a turbulent electric
field, across the confining magnetic field in controlled thermonuclear fusion
devices. The external electric field E = \nabla\bigvee is modeled by a
phenomenological potential V and the magnetic field B is considered uniform. It
is shown that, by introducing a small additive control term to the external
electric field, it is possible to create a transport barrier for this dynamical
system. The robustness of this control method is also investigated. This
theoretical study indicates that alternative transport barriers can be
triggered without requiring a control action on the device scale as in present
Internal Transport Barriers (ITB).
