Rydberg transitions in high angular momentum states of beryllium-like Si{sup 10+}

We have studied the structures of high angular momentum Rydberg states in Be-like Si{sup 10+} using ultraviolet spectroscopy of an excited fast ion beam at the Notre Dame Tandem Accelerator. The spectra of the n = 7-8, 8-9, and 9-10 transitions are reported for angular momentum states L>4. The unperturbed highest angular momentum state energies are formulated in terms of a core polarization model of long range electron-ion interactions. The lower L states exhibit perturbations due to mixing with core excited levels. Rydberg transitions between the core excited states have also been identified, and these radiative branches are found to be partially suppressed by autoionization effects at high n. Comparisons of the measurements with multi-configuration Dirac-Fock calculations are presented. For the highest L states, comparisons with many body perturbation theory calculations are discussed.