Measurement of relative oscillator strengths for Cr I lines – II. Measures for transitions from levels with excitation energy 2.54–3.46 eV

Relative oscillator strengths for 53 lines of Cr I, with excitation energies between 2.54 and 3.46 eV, have been measured using the Oxford spectroscopic furnace. The oscillator strengths for lines in the region of 2.5 eV have been placed on an absolute scale by comparison with 1 eV Cr I lines through temperatures measured using photoelectric pyrometry. The lifetime measurements by Kwiatowski et al. have also been used. The two methods agree to better than 1 per cent. This absolute scale has been extended to lines of excitation 3.5 eV using photoelectric pyrometry. The accuracy of relative oscillator strengths within this range of excitation is about 1 per cent, whilst that of the absolute scale is about 7 per cent, this latter value depending almost entirely on the accuracy of the lifetimes measured by Kwiatowski et al. Comparison is made with the experimental results and calculations of other authors. It is particularly satisfying that there is good agreement with the accurate results of Tozzi, Brunner & Huber for the few lines in common.