Energy levels and spectral lines of Ne VIII (original) (raw)

Energy levels and spectral lines of Ne VII

The European Physical Journal D, 2006

All experimental data on Ne VII, including previously unpublished beam-foil spectroscopy data, have been compiled and critically evaluated. More than a hundred spectral lines have been newly identified. For 40 transitions, the previous identifications have been revised. These revisions resolved all existing contradictions between previously published interpretations of the spectrum. An optimized level scheme has been derived from the total list of observed lines. About a hundred new energy levels have been found, including several highly excited hydrogenic levels. Based on these newly determined levels, as well as on the analysis of theoretical data, the ionization potential has been newly determined with improved confidence.

The Ne II spectrum

The European Physical Journal D, 2006

Spectra of neon-filled hollow cathode discharge lamps were observed by means of high-resolution Fourier-transform spectroscopy (FTS) covering the region from vacuum ultraviolet to near infrared. By combining these new measurements with results of other FTS and grating spectroscopy observations, we compiled a complete list of approximately 1700 spectral lines of Ne II covering the range from 324Å to 130000Å. All known energy levels of Ne II were derived from this line list with improved accuracy. The newly optimized energy levels were used to derive a set of Ritz wavelength standards in the vacuum ultraviolet that are in good agreement with the previously used data. An improved classification of energy levels was made with the help of parametric calculations, and the existing controversy in the naming of strongly mixed levels was resolved.

Spectroscopy of Ne IV in the wavelength range 450–1100

Journal of the Optical Society of America B, 1997

An analysis of the Ne IV spectrum was undertaken in the 450-1100-Å spectral range. The spectra were produced by the beam-foil method with beam energies of 1.2 and 2.5 MeV, respectively. The resolution that was achieved, with a normal-incidence 2-m spectrometer, was sufficient to identify 53 new Ne IV lines and, consequently, to determine 18 new levels in the quartet and doublet systems and one sextet term. The energy values of 13 additional levels were also revised. The classification work was facilitated by the use of scaled relativistic Hartree-Fock calculations.

New FTS measurements, optimized energy levels and refined VUV standards in the Ne III spectrum

The European Physical Journal D, 2006

All observed spectral lines of Ne III in the range 204Å to 36 µm (277 cm −1 to 490000 cm −1 ) have been compiled and critically evaluated. 57 visible and ultraviolet lines of Ne III have been precisely measured using Fourier transform spectroscopy. An optimized level scheme has been derived from the total list of observed lines. Relative positions of about 180 out of a total of 226 previously 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 (1.5-2.0) cm −1 . 127 precise wavelength standards in the region 210Å to 2900Å have been derived. 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 extreme ultraviolet region. The ionization potential has been increased by 4.5 cm −1 . The new value is (511543.5 ± 2.7) cm −1 (63.4233 eV ± 0.0003 eV).

New Classified Lines and Energy Levels in the Ne IV Spectrum

Spectroscopy Letters, 2007

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Extension and new level optimization of the Ne IV spectrum

Physica Scripta, 2012

Spectra of Ne emitted by a Penning discharge were recorded in the extreme ultraviolet region between 140 and 359 Å on a 10.7 m grazing-incidence spectrograph with phosphor storage image plates. These spectra provided 33 newly identified lines of Ne IV and improved measurements of an additional 58 lines in this spectral region. In addition, 42 lines were newly identified in the previously observed spectra of a capillary discharge (Gallardo et al 2007 Spectrosc. Lett. 40 879) in the vacuum ultraviolet region between 586 and 1410 Å. Combining these new measurements and identifications with those previously reported in the literature, we derived 45 new energy levels of Ne IV and significantly improved the accuracy of most of the previously known ones.

Quantum‐mechanical Calculations of Ne VII Spectral Line Widths

2007

We present in this paper quantum-mechanical calculations for the electron impact Stark linewidths of the 2s3s-2s3p transitions for the beryllium-like neon. Calculations are made in the frame of the impact approximation and for intermediate coupling, taking into account fine structure effects. A comparison between our calculations and experimental and other theoretical results showed a good agreement. This is the first time that we find such a good agreement between quantum and experimental linewidths of highly charged ions.

Stark shifts and transition probabilities in the Ne II spectrum

Stark shifts (d) and transition probabilities of the spontaneous emission (Einstein’s A values) of forty two singly charged neon (Ne ii) ion spectral lines have been measured in a linear, low pressure, pulsed arc at 35 300 K electron temperature and 1.83 × 10 23 m −3 electron density. Transition probabilities have been obtained using the relative line intensity ratio (RLIR) method. Stark shift values have also been calculated, using the semiclassical perturbation formalism (SCPF). The measured and calculated shift values and the measured A values have been compared to the existing data taken from available data sources.