Tr-Lif Lifetime Measurements and Hfr+cpol Calculations of Radiative Parameters in Vanadium Atom (V I)

Abstract

Radiative lifetimes of 79 levels belonging to the 3d 3 4s4p, 3d 4 4p, 3d 3 4s5p, 3d 4 5p, and 3d 3 4s4d configurations of V i with energy from 26,604.807 to 46,862.786 cm −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.

Experimentally Measured Radiative Lifetimes and Oscillator Strengths in Neutral Vanadium

“…These are discussed in Section 3. We also compare theoretically calculated log(gf ) values of Kurucz (2007) and recent results of Wang et al (2014), which combine measured lifetimes and theoretical branching fractions, with our new data, and confirm that experimentally measured log(gf) values are more reliable where these exist. Additionally, we provide log (gf ) values for 13 lines that have not been reported in any previous study, nine of which are in the infrared at wavelengths longer than 1.6 μm, which was the longest wavelength for any previously reported log(gf ) value in V I (Whaling et al 1985).…”

“…Comparison of the new log(gf ) values with theoretical values (Kurucz 2007) and values obtained with theoretical BFs and measured level lifetimes (Wang et al 2014) is shown in Figure 7. The improved accuracy of laboratory-measured log(gf ) values over theoretical values is clear.…”

“…acknowledges the support of the Linnaeus grant to the Lund Laser Centre from the Swedish Research Council (VR). The Kurucz (2007), and the right panel with results from Wang et al (2014). Table 5 Comparison between log(gf ) Values from Lawler et al (2014) and those from this Study and from Whaling et al (1985) Whaling et al (1985).…”

“…Their predicted contribution to the total BF was assigned to a "residual" value, which was used to scale the sum over l of I ul . The predicted BFs of Kurucz (2007) are used because we found these to be more reliable than those of Wang et al (2014) due to the strong cancellation effect reported by Wang et al (2014) affecting some of the transitions, in particular those depopulating the lowest excited odd-parity levels. Figure 4 shows comparisons of our measured BFs with those of Kurucz (2007) and Wang et al (2014).…”

Experimental and Theoretical Radiative Lifetimes, Branching Fractions, Transition Probabilities, and Oscillator Strengths of Nb i Levels

“…These effects can be eliminated by changing the slit width of the monochromator, reducing the energies of ablation and excitation lasers, and increasing the delay time between the ablation and excitation pulses. Moreover, a magnetic field of about 100 G produced by a pair of Helmholtz coils was applied to wash out possible quantum beats caused by the earth magnetic field and to effectively reduce recombination between electrons and ions (Wang et al 2014).…”