  We consider tunneling to the continuum in a multi-dimensional potential. It
is demonstrate that this problem can be treated as two separate problems: a) a
bound state and b) a non-resonance scattering problem, by a proper splitting of
the potential into two components. Finally we obtain the resonance energy and
the partial tunneling widths in terms of the bound and the scattering state
wave functions. This result can be used in a variety of tunneling problems. As
an application we consider the ionization of atomic states by an external
field. We obtain very simple analytical expressions for the tunneling width and
for the angular distribution of tunneling electrons. It is shown that the
angular spread of electrons in the final state is determined by the
semi-classical traversal tunneling time.
