Spectroscopic flame temperature measurements and their physical significance—V. Experimental determination of relative transition probabilities for 43 Fe I lines in the 3450–3950 Å wavelength region

Relative transition probabilities, as measured by the atomic emission spectroscopic technique, have been redetermined for 43 lines of Fe I under experimental conditions that in principle should yield accurate values. The Fe free-atoms are formed in a high temperature environment that has been shown to be isothermal and optically thin under the experimental conditions employed. The temperature of the iron atoms was measured by the reversal method, and the emission measurements were made so that the values obtained were strictly proportional to the line radiances. The high degree of correlation of the values reported with those obtained by the hook method is indicative of the overall reliability of these sets of data.