Ultraprecise Determination of Cs(nS_{1/2}) and Cs(nD_{J}) Quantum Defects for Sensing and Computing: Evaluation of Core Contributions.

We make absolute frequency measurements of Cs Rydberg transitions, |6S_{1/2},F=3⟩→|nS_{1/2}(n=23-90)⟩ and |nD_{3/2,5/2}(n=21-90)⟩, with an accuracy of less than 72 kHz. The quantum defect parameters for the measured Rydberg series are the most precise obtained to date. The quantum defect series is terminated at δ_{4}, showing that prior fits requiring higher order quantum defects reflect uncertainties in the observations.