Sr 5pnd J=3 autoionizing series and interference of excitation due to bound-state perturbation.

Using the isolated-core-excitation method we have measured the energies and widths of the three Sr J = 3 autoionizing 5pnd Rydberg series for n = 11--36. We have fitted our data to a six-channel multichannel quantum-defect theory model reproducing the observed energies, widths, and interactive excitation spectra for the three series. In addition, the effect of the bound 4d6s /sup 1/D/sub 2/ and 4d6s /sup 3/D/sub 2/ perturbers, which mix the bound 5snd /sup 1/D/sub 2/ and /sup 3/D/sub 2/ states, on the excitation spectra has been observed and accounted for.