Measurement of absolute f-values of iron group elements

Abstract

The preliminary results obtained with an atomic beam apparatus designed to measure absolute f-values for elements of the iron group were not in good agreement with results obtained by other techniques. In order to locate and eliminate sources of error in the atomic beam experiment each assumption made in the development of this technique has been analyzed and tested. Experimental methods used in this analysis and the conclusions which resulted are discussed in some detail. This thorough investigation of the experiment led to a number of modifications of the apparatus and improved techniques for making accurate measurements. These improvements and their effects upon the results are described. Atomic beam measurements of absolute f-values for resonance lines in the spectra of Cu I, Mn I, Fe I, and Cr I are presented and compared with values obtained by other investigators. An experimental curve of growth for one line of each element has been determined and compared with the theoretical curve of growth. The good agreement obtained indicates that the atomic beam method gives results which vary with experimental conditions as the theory predicts. Suggestions are given for further absolute f-value research using the atomic beam method.