This report, the second of a series associated with the development of the spectrographic determination of U235 at the Oak Ridge Gaseous Diffusion Plant, describes the development of the direct-reading scanning technique, using a Jarrell-Ash 21-foot Wadsworth spectrograph with a hollow cathode discharge tube to excite the uranium samples. For a determination consisting of ten scans on a single cathode containing the unknown, and ten scans on a single cathode containing a comparison standard, the precision obtained was from ±1.2 to 1.8% of the amount present over a concentration range of 8-12% U235. All precisions are expressed at the 95% confidence level.
Ted Lee and Lewis H. Rogers, "The Spectrographic Determination of Uranium 235. Part II. Using a Direct-Reading Attachment and a Hollow Cathode Source," Appl. Spectrosc. 15, 3-6 (1961)