The Spectrographic Determination of Uranium 235. V. Routine Application of a Multiple Hollow Cathode Source Assembly and a Direct-Reading, Littrow Grating Spectrograph

Abstract

This paper, the fifth of a related series, describes the routine application of a rapid, high-precision procedure and a high resolution spectrograph to the isotopic analysis of uranium. The procedure, which evolved from the development described in previous papers of this series, includes a simple sample preparation and a hollow cathode source designed for rapid sample changing. The procedure also involves a high degree of automation and eliminates the reference measurement and background correction The precision at the level of naturally occurring uranium (0.7115% U235) measured under routine conditions, is ±2.1% of the amount present for a single cathode determination expressed at the 95% confidence interval. In the vicinity of 90% U235 the precision is 0 07% of the amount present for a single cathode determination. Approximately 7½ min is required for a determination, including sample preparation, measurement, and calculations The maximum capacity of the instrument is over 60 samples per 8 hr day, the instrument is presently applied to a routine load varying from 20 to 5 0 samples per day. In addition to the U235 determination, a preliminary calibration and evaluation for U236 is included