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Automatic measurements and computations for radiochemical analyses

January 1, 1960

In natural radioactive sources the most important radioactive daughter products useful for geochemical studies are protactinium-231, the alpha-emitting thorium isotopes, and the radium isotopes. To resolve the abundances of these thorium and radium isotopes by their characteristic decay and growth patterns, a large number of repeated alpha activity measurements on the two chemically separated elements were made over extended periods of time. Alpha scintillation counting with automatic measurements and sample changing is used to obtain the basic count data. Generation of the required theoretical decay and growth functions, varying with time, and the least squares solution of the overdetermined simultaneous count rate equations are done with a digital computer. Examples of the complex count rate equations which may be solved and results of a natural sample containing four alpha-emitting isotopes of thorium are illustrated. These methods facilitate the determination of the radioactive sources on the large scale required for many geochemical investigations.

Publication Year 1960
Title Automatic measurements and computations for radiochemical analyses
DOI 10.1021/ac60165a013
Authors J. N. Rosholt, J. R. Dooley
Publication Type Article
Publication Subtype Journal Article
Series Title Analytical Chemistry
Index ID 70010845
Record Source USGS Publications Warehouse