Abstract
IN recent clinical radioactive tracer studies using sodium-24, phosphorus-32 and iodine-131, it was found desirable to have a reliable and convenient radioactive standard, of similar beta- and gamma-ray energy, easily reproducible, of negligible radioactive decay and with adequate carrier protection against exchange reactions upon the glass walls of Geiger–Muller liquid counters1. The radioactive isotope, potassium-40 of normally occurring potassium, is present to one part in 9,000 and has a half-life of 12.7 ± 0.5 × 108 years2 with a beta-ray spectrum of maximum energy 1.38 MeV. and a gamma-ray of energy 1.5 MeV.
Similar content being viewed by others
Article PDF
References
Veall, N., Brit. J. Rad., 21, 347 (1948).
Sawyer, G. A., and Wiedenbeck, W. L., Phys. Rev., 79, 490 (1950).
Barnes, R. B., and Salley, D. J., Indust. Eng. Chem. (Anal. Edit.), 15, 4 (1943).
Putman, J. L., Brit. J. Rad., 23, 46 (1950).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
CHALMERS, T. Calibration of Geiger-Müller Liquid Counters by the Radioactivity of Potassium-40. Nature 168, 870 (1951). https://doi.org/10.1038/168870a0
Issue Date:
DOI: https://doi.org/10.1038/168870a0
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.