This work will concentrate on the mechanisms that produce neutralized
atoms upon scattering of ions from metal surfaces. Three mechanisms are
usually considered for ion neutralization at metal surfaces. Those are:
resonance tunneling; Auger neutra
lization and surface plasmon-mediated ion
neutralization. The third mechanism, namely surface plasmon-mediated ion
neutralization, was suggested and calculated by us in an earlier work, where a
unitary transformation was introduced to the second quantized Hamiltonian.
The atoms are described by a state orthogonal to all conduction band states of
the metal. The transformation gave rise to an additional term in the matrix
elements ''the orthogonalization term''. This theory of applying a unitary
transformation to the second quantized Hamiltonian is applied to the resonance
and Auger neutralization mechanisms. The orthogonalization correction to the
neutralization rate is found to be important at small distances from the surface
when, applied to the scattering of protons from aluminum surface.