Xue Shang

TR-LIF LIFETIME MEASUREMENTS AND HFR+CPOL CALCULATIONS OF RADIATIVE PARAMETERS IN VANADIUM ATOM (V I)

Radiative lifetimes of 79 levels belonging to the 3d {sup 3}4s4p, 3d {sup 4}4p, 3d {sup 3}4s5p, 3d {sup 4}5p, and 3d {sup 3}4s4d configurations of V I with energy from 26,604.807 to 46,862.786 cm{sup –1} have been measured using time-resolved laser-induced fluorescence (TR-LIF) spectroscopy in laser-produced plasma. The lifetime values reported in this paper are in the range of 3.3-494 ns, and the uncertainties of these measurements are within ±10%. A good agreement was obtained with previous data. HFR+CPOL calculations have been performed and used to combine the calculated branching fractions with the available experimental lifetimes to determine semi-empirical transition probabilities for 784 V I transitions.

Radiative lifetime measurements of some Gd I and Gd II levels using time-resolved laser spectroscopy

Radiative lifetimes of 27 levels (27?041.751?38?434.97?cm?1) in Gd I and 27 levels (27?130.397?45?394.925?cm?1) in Gd II have been measured using the time-resolved laser-induced fluorescence method. Laser ablation was used to generate Gd atoms and ions on a Gd plate. The measured lifetime values range from 4.0 to 90?ns with an uncertainty of 5% or less. Of all the results, to our knowledge, lifetimes of 23 Gd II levels and 11 Gd I levels are reported for the first time. Good agreement between our results and the previous ones has been achieved.

Radiative lifetimes, branching fractions, transition probabilities and oscillator strengths of some levels for neutral yttrium

The radiative lifetime measurements using the time-resolved laser-induced fluorescence (TR-LIF) technique are reported for 34 levels of Y I between 27 824.50 and 50 254.0 cm−1, among which 27 lifetimes are reported for the first time. The branching fraction (BF) measurements based on the emission spectrum of a hollow cathode lamp (HCL) were performed for 12 of these levels, and the results of 64 lines between 274.250 and 670.063 nm were obtained. By combining them with lifetime values, the transition probabilities and absolute oscillator strengths of these lines were determined. The lifetime and oscillator strength results are in general good agreement with the data by Hannaford et al (Hannaford et al 1982 ApJ 261 736).

Experimental branching fractions, transition probabilities and oscillator strengths in Gd I and Gd II

Branching fractions of 13 levels in Gd I and 12 levels in Gd II were experimentally determined based on the emission spectrum of a hollow cathode lamp. In addition, transition probabilities and oscillator strengths for 66 lines of Gd I and 74 lines of Gd II were derived from a combination of the radiative lifetimes reported in the earlier literature and the branching fractions obtained in the present paper.

Experimental branching fractions, transition probabilities and oscillator strengths in Eu I

Branching fractions (BFs) of 64 spectral lines for 27 levels in Eu I were measured by the emission spectrum of a hollow cathode lamp (HCL). The transition probabilities and oscillator strengths of these lines were determined by using the time-resolved laser-induced fluorescence technique to combine the BFs with experimental radiative lifetimes of the relative levels reported in the literature.

Landé factor and lifetime measurements for odd-parity levels of Cr I by time-resolved laser spectroscopy

The Lande g J factors of 35 levels, and the radiative lifetimes of 43 levels, of neutral chromium in the energy range 23 305.0026 to 53 782.78 cm−1 were measured by time-resolved laser-induced fluorescence and Zeeman quantum beat methods in laser-ablation plasma. Good agreements between the present results and the previous experimental values were achieved for both g J factors and lifetimes. The measured g J values are quite close to those calculated under the pure LS-coupling scheme. The lifetime values obtained are in the range 11.4 to 193 ns. To the best of our knowledge, 15 of the Lande factors and 17 of the lifetimes are reported for the first time.