Spectrographic Determination of Uranium 235

Abstract

This report is the first of a series associated with the development of the spectrographic determination of uranium 235 at the Oak Ridge Gaseous Diffusion Plant The present report, summarizing the development prior to November 1950, deals with the precision obtained using d c arc excitation, photographic recording, and a 21-foot Jarrell-Ash Wadsworth spectrograph in the second order. Measurements were made employing different spectral lines, slit widths, and slit types. For each determination consisting of the average of 10 measurements, a precision of ±0.04 weight per cent uranium 235, expressed at the 95% confidence level, was obtained in the vicinity of naturally occurring uranium (0.7115% uranium 235).