Lifetime measurements in neutral and singly ionized vanadium

Radiative lifetimes of ten odd-parity levels of V I belonging to the 3d(3)4s4p and 3d(4)4p configurations and of 11 odd-parity levels of V II belonging to the 3d(3)4p configuration are reported. The lifetimes were measured with use of single-step excitation and time-resolved fluorescence spectroscopy. The neutral and singly ionized vanadium atoms were produced in a laser-induced vanadium plasma. (c) 2006 Optical Society of America

Measurements of excited state lifetimes and oscillator strengths in Pt II

We report on radiative lifetime measurements of short-lived states in singly ionized platinum by excitation with pico-second laser pulses and subsequent time-resolved detection. The upper levels were populated from metastable ion levels in a laser-generated plasma using radiation in the UV/VUV spectral range. The following lifetimes were obtained: tau(5d(8)(F-3(4))6p(1/2), J = 7/2) = 3.9(3) ns, tau(5d(8)(F-3(4))6p(3/2), J = 9/2) = 3.5(3) ns and tau(5d(8)(F-3(3))6p(1/2), J = 5/2) = 2.6(3) ns. By using relative intensities of the lines found in the literature, oscillator strengths were determined

Hyperfine structure in the sequence of sodium S states

The hyperfine structure for the 6, 7 and 8 2 S 1/2 states of 23 Na was measured by optical double-resonance techniques. The states were populated by step-wise excitation using two CW dye lasers. For the dipole interaction constant a, a(6 2 S 1/2 ) = 37.5(2) MHz, a(7 2 S 1/2 )=20.9(1) MHz, a(8 2 S 1/2 )=12.85(10) MHz. were obtained. Theoretical calculations of the hyperfine structure were performed for the 3-8 2 S 1/2 states using many-body perturbation techniques. When polarization as well as certain correlation effects are included in the calculation, an agreement with the experimental values within 2% is obtained

Experimental Ca I oscillator strengths for the 4p-5s triplet

Context. Transition lines of neutral calcium are observed in the spectra of stellar and substellar objects. In particular, the abundance of α-elements in metal-poor stars can place important constraints on the galactic chemical evolution. Such stellar abundance analyses rely heavily on accurate values for the oscillator strength of the observable transitions. Theoretical oscillator strengths are available for most neutral calcium lines visible in stellar spectra, but there are a limited number of experimental values in the literature. Aims. We present new and improved experimental oscillator strengths for the optical Ca 

Lifetime measurements for excited states of rare-earth atoms using pulse modulation of a cw dye-laser beam

By pulse-modulating a cw dye-laser beam and employing the delayed-coincidence technique, we have determined the natural radiative lifetimes of a number of atomic states in rare-earth atoms Eu, Dy, and Yb. In the measurements, which were performed on an atomic beam, exponential decay curves with good statistics were obtained using short measuring times. The general features of the technique are discussed. When possible, oscillator strengths are deduced and compared with literature values

Time-resolved laser spectroscopy on high-lying states in neutral oxygen

Radiative lifetimes have been measured for five triplet states of atomic oxygen. The oxygen atoms were generated by photodissociation of NO2 and the investigated states were populated through a two-step process involving a two-photon excitation to the lowest excited triplet state of even parity, 2p33p 3P, followed by a one-photon excitation to the investigated state. A similar scheme is applicable to the study of excited states in many light atoms