  The Bogoliubov equations of the quasi-particle excitations in a weakly
interacting trapped Bose-condensate are solved in the WKB approximation in an
isotropic harmonic trap, determining the discrete quasi-particle energies and
wave functions by torus (Bohr-Sommerfeld) quantization of the integrable
classical quasi-particle dynamics. The results are used to calculate the
position and strengths of the peaks in the dynamic structure function which can
be observed by off-resonance inelastic light-scattering.
