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Potassium-calcium decay system

Brian D. Marshall
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Abstract

Potassium has three isotopes (see Potassium ); potassium-40 ( 40 K) is radioactive and decays to both calcium-40 ( 40 Ca) and argon-40 ( 40 Ar). The combined half-life of 40 K is 1.25 billion years. The branched decay scheme of 40 K is shown in Figure P33 . It decays by β- decay to 40 Ca and to 40 Ar by both electron capture and positron decay (see Potassium-argon decay system ). Although 89.52% of the decays produce 40 Ca, the system is of somewhat limited use due to the large natural abundance of 40 Ca (96.9% of calcium, see Calcium ).

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Brian D. Marshall. 1999. Potassium-calcium decay system. https://doi.org/10.1007/1-4020-4496-8_260

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