High precision calculations of Rydberg sodium: Radiometry with the Earth's sodium layer

We accurately calculate the Rydberg spectra of the atomic sodium for the S, P, D, and F series up to n = 60 within the Ritz variational method. The positive core-electron interaction is modeled by the l-dependent single-electron valence potential with spin-orbit coupling. We extend available data (e.g., reported in the NIST database) on scalar and tensor polarizabilities as well as Einstein coefficients for spontaneous and stimulated emission of Rydberg states to involve higher principal quantum numbers. We show a detailed comparison with present theoretical and experimental findings. In our investigations, we aim at the microwave frequency band of 90 to 150 GHz, of interest in precision microwave relative radiometric laser excitation of the Earth’s atmospheric sodium layer.