Experimental f-value and isotopic structure for the Ni I line blended with [OI] at 6300A

We have measured the oscillator strength of the Ni I line at 6300.34 \AA, which is known to be blended with the forbidden [O I] $\lambda$6300 line, used for determination of the oxygen abundance in cool stars. We give also wavelengths of the two isotopic line components of $^{58}$Ni and $^{60}$Ni derived from the asymmetric laboratory line profile. These two line components of Ni I have to be considered when calculating a line profile of the 6300 \AA\ feature observed in stellar and solar spectra. We also discuss the labelling of the energy levels involved in the Ni I line, as level mixing makes the theoretical predictions uncertain.Comment: Accepted for publication in ApJLetter

Structure and line strengths in extreme jK coupling: an experimental and theoretical study in Ni ii

The spectrum emitted from a nickel hollow cathode has been recorded with a Fourier transform spectrometer. Two dense groups of lines just above 18 000 Å have been identified as the transitions 3d8 (3F)5f-3d8 (3F)6g and 3d8 (3F)5g-3d8 (3F)6h in Ni II. The level structure of the configurations involved in these transitions has been studied by fitting the Slater parameters of the energy matrices to the observations. The fitted parameters have been used for calculating the relative line strengths in the transition arrays. Comparisons with the observed intensities show very good agreement

The 3d-4f Transition in S VII Observed in a Laser-Produced Plasma

The energy levels of the 2p54f configuration in neon-like sulphur, S VII, have been derived from spectral lines in the region 330-375 Å. The lines, which were identified as belonging to the 3d-4f transition, were emitted from a laser-produced plasma. The structure in the 4f configuration has been studied through a parametric fit of Slater integrals