相关论文: The FERRUM project: Experimental lifetimes and tra…

Aims: We measure transition probabilities for Cr II transitions from the z ^4H_J, z ^2D_J, y ^4F_J, and y ^4G_J levels in the energy range 63000 to 68000 cm^{-1}. Methods: Radiative lifetimes were measured using time-resolved laser-induced…

Accurate transition probabilities for forbidden lines are important diagnostic parameters for low-density astrophysical plasmas. In this paper we present experimental atomic data for forbidden [FeII] transitions that are observed as strong…

Fe II radiative lifetimes were measured applying the time-resolved nonlinear laser-induced fluoresence technique. We investigated 21 levels of up to 47000 1/cm. The uncertainties are typically 2-3%. The lifetimes provide an improved…

This work reports new experimental radiative lifetimes and calculated oscillator strengths for transitions from 3d8 4d levels of astrophysical interest in singly ionized nickel. Radiative lifetimes of seven high-lying levels of even parity…

We present experimental atomic lifetimes for 12 levels in Sb I, out of which seven are reported for the first time. The levels belong to the 5p$^2$($^3$P)6s $^{2}$P, $^{4}$P and 5p$^2$($^3$P)5d $^{4}$P, $^{4}$F and $^{2}$F terms. The…

Many energy levels of singly ionised iron (Fe II, $Z=26$) remain uncertain or experimentally unknown. Their identification and spectral line data are required in reliable astrophysical spectral analyses. In motivation for improving the…

Context. In many plasmas, long-lived metastable atomic levels are depopulated by collisions (quenched) before they decay radiatively. In low-density regions, however, the low collision rate may allow depopulation by electric dipole (E1)…

Using the inherent timing stability of pulses from a mode-locked laser, we have precisely measured the cesium $6P_{3/2}$ excited state lifetime. An initial pump pulse excites cesium atoms in two counter-propagating atomic beams to the…

Energy levels, lifetimes, and transition probabilities for transitions between computed levels of 3d^5 of Fe IV are reported. The E2 and M1 transition probabilities are compared with earlier theoretical results, often only the values…

This work reports new experimental radiative lifetimes and calculated oscillator strengths for transitions of astrophysical interest in singly ionized cobalt. More precisely, nineteen radiative lifetimes in Co+ have been measured with the…

Energies and lifetimes are reported for the lowest 136 levels of Fe XIV, belonging to the (1s$^2$2s$^2$2p$^6$) 3s$^2$3p, 3s3p$^2$, 3s$^2$3d, 3p$^3$, 3s3p3d, 3p$^2$3d, 3s3d$^2$, 3p3d$^2$ and 3s$^24\ell$ configurations. Additionally,…

Radiative lifetimes from laser-induced fluorescence measurements, accurate to about +/- 5 percent, are reported for 41 odd-parity levels of Hf II. The lifetimes are combined with branching fractions measured using Fourier transform…

The lifetimes of the $6d \ ^2D_{3/2}$ and $6d \ ^2D_{5/2}$ states in Fr are estimated to be 540(10) ns and 1704(32) ns respectively. They are determined by calculating the radiative transition amplitudes of the allowed electric dipole (E1)…

New radiative lifetimes, measured to $\pm$ 5 % accuracy, are reported for 31 even-parity levels of Fe I ranging from 45061 cm$^{-1}$ to 56842 cm$^{-1}$. These lifetimes have been measured using single-step and two-step time-resolved…

We have calculated energy levels and lifetimes of 4f7 and 4f6 5d configurations of Gd IV using Hartree-Fock and configuration interaction methods. This allows us to reduce significantly the uncertainty of the theoretical determination of…

We measure the lifetime of the 8s level on a magneto-optically trapped sample of ^{210}Fr atoms with time-correlated single-photon counting. The 7P_{1/2} state serves as the resonant intermediate level for two-photon excitation of the 8s…

Energy levels, Land\'{e} $g$-factors and radiative lifetimes are reported for the lowest 182 levels of the 3d$^4$, 3d$^3$4s and 3d$^3$4p configurations of Fe~V, Co~VI and Ni~VII. Additionally, radiative rates ($A$-values) have been…

We report new experimental Fe I oscillator strengths obtained by combining measurements of branching fractions measured with a Fourier Transform spectrometer and time-resolved laser-induced fluorescence lifetimes. The study covers the…

New branching fraction measurements based primarily on data from a cross dispersed echelle spectrometer are reported for 84 lines of Co II. The branching fractions for 82 lines are converted to absolute atomic transition probabilities using…

The helium atom, with one nucleus and two electrons, is a prototypical system to study quantum many-body dynamics. Doubly-excited states, or quantum states in which both electrons are excited by one photon, are showcase scenarios of…