High-resolution spectroscopy and multichannel quantum-defect-theory analysis of the np and nf Rydberg series of Xe below the P3<mml:…

This article reports on the application of a long-pulse near-Fourier-transform-limited ultraviolet (UV) laser to a high-precision spectroscopic investigation of the np and nf Rydberg series converging to the (5p)⁵4pt0ex²P3/2 ground state of Xe⁺. These series were measured by pulsed-field ionization following single-photon absorption from the (5p)⁵(6s)¹4pt0ex³P₂ metastable state of Xe in a doubly skimmed supersonic expansion. They were analyzed by multichannel quantum-defect theory to determine the ionization energies of all natural isotopes of Xe, and to quantify the isotopic shifts of all natural isotopes and the hyperfine structure in the spectra of ¹²⁹Xe ($I=1/2$) and ¹³¹Xe ($I=3/2$). Special attention was given to the determination of precise and accurate transition frequencies by careful consideration of systematic uncertainties originating from the DC- and AC-Stark effects, the first- and second-order Doppler effects, the photon-recoil shift, and the calibration of the laser frequency including the analysis of frequency chirps during the laser pulses.