Experimental gƒ-VALUES for Seventy Elements.

Abstract

Relative intensities of 39,000 spectral lines with wavelengths between 2000 and 9000 A have been determined on a uniform energy scale for seventy elements. The lightsource was an arc between copper electrodes to which a single element was added in the ratio of 1 atom of element to 1000 atoms of copper. The spectrograms were calibrated with standard lamps. The temperature of the arc was determined, by comparison of the observed intensities with published relative gf- values, to be 5100 deg plus or minus 110 deg K. The degree of ionization of eleven elements in the arc was determined by comparison of intensities in spectra of neutral and ionized atoms with known absolute gf-values. With the aid of Saha's ionization equation, the electron density in the arc was found to be 2.4 x 10/sup 11/ cm/sup -3/. The ionization of seventy elements separately added to the arc was then calculated with Saha's equation. A correction was made for diffusion of atoms from the arc stream. With this information, relative values of gf on a uniform scale can be computed for the 25000 lines which have been classified. By calibration with known absolute gf-values, the scale is put on an absolutemore » basis. The accuracy of the results is discussed. A curve of growth for Y in the sun is constructed with the gf-values to test their utility. (auth)« less