Sampling and data-taking strategies in X-ray fluorescence assay of low S/N solutions
Abstract
This projet was initiated for the purpose of demonstrating the feasibility of on-line X-ray fluorescence (XRF) analysis for the nondestructive assay of fissile elements (SNM) in reactor fuel reprocessing (dissolver) solutions, using wavelength dispersive X-ray fluorescence analysis because of its high immunity to the intense gamma emissions of the solutions. A prime objective of this project was the identification and dimensioning of the parameters critical to XRF assays of high accuracy. The concepts presented herein, though directed primarily to assay of solutions with emphasis on low signal-to-noise conditions and low count rates, are applicable to all assays of solids, slurries, and gases. This study shows that for solution analysis total sampling gives total mass assays with no need for solution density or tank volume measurements. Time savings and standard deviations are both benefited by systematically predetermining the count requirements of analysts, standards, and backgrounds by the use of equations based on propagation of error considerations. This becomes quite important when assaying dilute solutions, in which the signal-to-noise ratios of the X-ray intensities are very low. When counting times are long, short dwell times at each spectrometer setting significantly counteract error accumulation arising from long-term instrumental drift.
- Publication:
-
Presented at the 34th Denver X-ray Conference
- Pub Date:
- 1985
- Bibcode:
- 1985xray.conf.....H
- Keywords:
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- Accuracy;
- Assaying;
- Nuclear Fuels;
- Sampling;
- Strategy;
- X Ray Fluorescence;
- Data Acquisition;
- Errors;
- Signal To Noise Ratios;
- Uranium;
- Atomic and Molecular Physics