Atomic Transition Probabilities for Visible and Near‐Ultraviolet Spectral Lines in Co i

We report the measurement of branching fractions and absolute transition probabilities for 103 Co I spectral lines in the wavelength range between 293 and 1008 nm. Hollow cathode spectra recorded using the Fourier transform spectrometer at the National Solar Observatory are used to determine the branching fractions. An absolute scale is established using recently reported radiative lifetimes from time-resolved laser-induced fluorescence measurements. The results are for the most part in agreement with previously reported measurements but reduce the uncertainties by an average factor of 2.5. Two-thirds of the transition probabilities reported here have uncertainties between ±5% and ±10%. The lines studied in this work connect the low-lying even-parity levels of Co I to odd-parity levels between 28346 and 34134 cm -1 .