New FTS Measurements, Optimized Energy Levels and Refined VUV Standards in the Ne III Spectrum
Alexander Kramida, Gillian Nave
All observed spectral lines of Ne III in the range 204 to 36 m have been compiled and critically evaluated. An optimized level scheme has been derived from the total list of observed lines. Relative positions of about 70 of known energy levels of Ne III have been determined with improved accuracy compared to previous studies. Excitation energies of almost all excited levels have been revised by 0.5 1.5 cm-1. Thirty two precise wavelength standards have been derived with well-defined uncertainties in the region 210 1030 . Concepts of error current and covariance matrix have been implemented in a computational algorithm that permits one to derive the uncertainties of Ritz wavelength standards obtained from a set of least-squares-optimized energy levels. Nine new energy levels have been found, and 16 new transitions have been identified in the EUV range. The ionization potential has been revised by 2 cm-1. The new value is 511541 4 cm-1 (63.4230 0.0005 eV).