Spectrum of doubly ionized neon (original) (raw)

EquilibriumK-shell excitation of highly ionized neon

Zeitschrift f�r Physik A Atoms and Nuclei, 1979

Augerelectron emission from foil-excited Ne-ions (6 to l0 MeV beam energy) has been measured. The beam-foil time-of-flight technique has been applied to study electronic transitions of metastable states (delayed spectra) and to determine their lifetimes. To achieve a line identification for the complex structure observed in the prompt spectrum, the spectrum is separated into its isoelectronic parts by an Augerelectron-ion coincidence correlating the emitted electrons and the emitting projectiles of well defined final charge states qI' Well resolved spectra were obtained and the lines could be identified using intermediate coupling Dirac-Fock multiconfiguration calculations. From the total KLL-Augerelectron transition probabilities observed in the electronion coincidence experiment for Ne (10 MeV) the amount of projectiles with one K-hole just behind a C-target can be estimated. For foil-excited Ne-projectiles in contrast to single collision results the comparison of transition intensities for individual lines with calculated transition probabilities yields a statistical population of Li-and Be-like configurations.

Electron-impact excitation of some low-lying levels of neon

Physical Review A, 1984

First-ordex' many-body theory has been used to calculate the differential and integral cross sections for electron-impact excitation of all the 3s, 3s' levels, and certain of the 3p, 3p' levels of neon, fox' incident electron enex'gies ranging from 20 to 120 eV. The x'esulting differential cross sections foI' thc excitation of thc optically allo&cd Pl and thc Pl lcvcls sholv, foI thc 10 484 80 Rngular range, a discrepancy no gx'eatex than 15% when compared vrith x'ecent expeximental results, except fol very fcw points. Spin-orbit coupling &as included in thc Xvave fuQctions and its cffcct on dctclminlng thc diffclcntial cross sections foI thc I l lcvcl %'Rs found to bc very importRQt foI scattering angles less than 40'. For the differential cross sections of the other 3s, 3s' levels the discx'epancy in the 30'&8& 80' x'ange is only slightly larger than the experimental erx'ors. For the 3p, 3p' levels considered here, ere have found strong disagreement mth experimental data and there Is also substantial disagrccmcnt among thc vanous thcorctical I'csults. Is interesting to note though that thc f11st reported calculation for the electron-impact excitation of the unresolved 3s, 3s' levels of neon by Massey and Mohr " was with the distorted-wave approximation with thc additional slmpli" fication that the asymptotic form of the distorted waves were Used and the partial-wave phase shifts were calculated using Jeffrey's (also called &KB) approximation.

On the Time Resolved Optogalvanic Spectroscopy of Neon in a Hollow Cathode Discharge

Journal of Nano- and Electronic Physics, 2021

Time resolved optogalvanic (OG) signals of 1s4-2p8 (650.65 nm) and 1s3-2p7 (653.29 nm) transitions have been studied in neon DC plasma. Numerical fit of the signals based on four-term rate equation model has been used to elucidate the contributions to the signal from four 1si levels. Evolution of decay rates of four 1si neon states as a function of discharge current has been studied. The dominant discharge processes for the first transition were photoionization and impact ionization, while for the second transition-the metastable-metastable collisional ionization mechanism was added to the previously mentioned mechanisms to produce the OG signal. The effective lifetimes of the 1si states have been determined for both transitions, where 2 s is found for the resonance state 1s2, while the 1s3,4,5 have an almost equivalent effective lifetime of 40 s. The long effective lifetime of all 1s2,4 states in comparison with their radiative lifetimes is attributed to the radiation trapping effect. The contribution of the 1si states to the OG signals has been studied. 1s3 state involvement was most important in the 1s3-2p7 transition signal, while the 1s4 state has a large contribution to the 1s4-2p8 transition signal.

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.

Collisional Ionization of Excited State Neon in a Gas Discharge Plasma

Contributions to Plasma Physics, 1995

We report the first 'case where it is possible to clearly identify and quantitatively characterize the dominant physical processes contributing to production of the optogalvanic effect (OGE) signal in a discharge plasma. This work concentrates on the simplest case where only two states are involved in the optical transition. The theoretical model with only four parameters is in excellent agreement with the experimentally obtained time-resolved OGE waveforms. The collisional ionization rate in the upper state is twice as fast as that in the lower state although the two states are only separated by 1.94 eV. We conclude that the optogalvanic effect of the neon 640.22 nm transition is due primarily to the electron collisional ionization of the neon atoms. An alternative interpretation for the lengthening of the final state lifetime is also included (see Appendix).

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.

A study of neon–nitrogen interactions in d.c. glow discharges by optical emission spectroscopy

Thin Solid Films, 2001

Neon-nitrogen d.c. diode glow discharges have been investigated through the use of spatially resolved optical emission spectroscopy. This technique has enabled the discharges to be sampled from inside the cathode sheath and plasma regions. All discharges were operated at -2 kV cathode bias and 6 Pa total pressure. By evaluating spectral line intensity ratios (SLIRs) that incorporate ion species, the principal findings are as follows: first, the cathode current density at low nitrogen partial pressures is boosted by Penning ionisation of nitrogen by neon; evidence of this mechanism is provided by maxima in nitrogen ion-based SLIRs and minima in neon ion-based SLIRs occurring at low nitrogen concentrations. Second, although the optimum nitrogen partial pressure for Penning ionisation appears to be approximately 5%, the maxima in cathode current density and N yN SLIRs q 0 2 2 occur at 10-15%; we speculate that a dissociative Penning ionisation mechanism is predominant at 5% but conventional (nondissociative) Penning ionisation, with possible contributions from other mechanisms (such as electron impact ionisation of nitrogen) become significant at 10-15% nitrogen concentration. ᮊ

Spectroscopy of neon for the advanced undergraduate laboratory

American Journal of Physics

We describe a spectroscopy experiment, suitable for upper-division laboratory courses, that investigates saturated absorption spectroscopy and polarization spectroscopy in a neon discharge. Both experiments use nearly identical components, allowing students to explore both techniques in a single apparatus. Furthermore, because the wavelength of the laser is in the visible part of the spectrum (640 nm), the experiment is well-suited for students with limited experience in optical alignment. The labs nicely complement a course in atomic or plasma physics, provide students with the opportunity to gain important technical skills in the area of optics and lasers, and can provide an introduction to radio-frequency electronics. V

One- and two-photon laser optogalvanic spectroscopy of neon in the 570–626nm region

Optics Communications, 2008

Eleven two-photon transitions originating from the 2p 5 3s[3/2] 2 , 2p 5 3s 0 [1/2] o , 2p 5 3s[3/2] 1 , and 2p 5 3s 0 [1/ 2] 1 states to the 2p 5 4d configuration states have been investigated in the optogalvanic spectrum of neon in the visible region (570-626 nm) for the first time. The two-photon assignments are confirmed by evaluating the temporal evolution, power dependency, and line widths of the optogalvanic signals. The time evolution of the optogalvanic signals for the two-photon transition originating from the metastable 2p 5 3s[3/2] 2 state to the 2p 5 4d 0 [3/2] 2 state has also been studied at different discharge currents.

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.