Inelastic scattering effects in recurrence spectra of He atoms in a magnetic field

We report recurrence spectra of He atoms in a magnetic field near the second and third ionization thresholds. The analysis of the recurrence spectra reveals the presence of new peaks. It is shown that these peaks are signatures of inelastic (interchannel) scattering events of active electrons by the atomic cores and they correspond to combinations of electron closed-orbits in different channels. Our calculations are based on a formulation combining the standard closed-orbit theory away from the core region with the close-coupling R-matrix theory in the core region.