  The impact of an edge radial electric field on the particle orbits and the
orbital spectrum in an axisymmetric toroidal magnetic equilibrium is
investigated using a guiding center canonical formalism. Poloidal and
bounce/transit-averaged toroidal precession frequencies are calculated,
highlighting the role of the radial electric field. The radial electric field
is shown to drastically modify the resonance conditions between particles with
certain kinetic characteristics and specific perturbative non-axisymmetric
modes and to enable the formation of transport barriers. The locations of the
resonances and the transport barriers, that determine the particle, energy and
momentum transport are shown to be accurately pinpointed in the phase space, by
employing the calculated orbital frequencies.
