Topic summary
Neptunium series
Extracted from the Wikipedia article Decay chain.
Neptunium series
The 4n+1 chain of neptunium-237 is commonly called the "neptunium series" or "neptunium cascade". In this series, only two of the isotopes involved are found naturally in significant quantities, namely the final two: bismuth-209 and thallium-205. Some of the other isotopes have been detected in nature, originating from trace quantities of Np produced by the (n,2n) knockout reaction in primordial U.