Neptunium series

The Neptunium series is the natural decay series of the Neptunium isotope ²³⁷ Np. Your final nuclide is the thallium isotope ²⁰⁵ Tl; For a long time it was believed that the bismuth isotope ²⁰⁹ Bi was stable and the end point of the series. The series can also be continued beyond the neptunium to even heavier transuranic elements . The representation is only continued up to ²⁴¹ Pu, which is produced in small quantities in nuclear reactors (extension in purple ).

The Neptunium series is also referred to as the "prehistoric" series, since the ²³⁷ Np present when the earth was formed has already completely decayed. Today the neptunium series exists again - albeit in an artificial way - because initial nuclides such as ²⁴¹ Pu, ²³⁷ Np and ²³⁷ U are incubated in nuclear reactors as by- products or main products .

Natural radioactive decay series: Neptunium series (purple)

4n + 1 row

Decay series of ²³⁷ Np (the very improbable series over the isotopes ²²¹ Ra and ²¹⁷ Rn are not shown); Z shows the atomic number (number of protons), N the number of neutrons of the isotopes

nuclide	Decay	HWZ	E / MeV	Decay product
241 Pu	β - 99.9975% α 0.0025%	14.4 a	0.021 5.14	241 At 237 U
241 On	α	432.2 a	5.638	237 Np
237 U	β -	6.75 d	0.519	237 Np
237 Np	α	2.144 x 10 6 a	4,959	233 Pa
233 Pa	β -	26,967 d	0.571	233 U
233 U	α	1.592 x 10 5 a	4.909	229 Th
229 Th	α	7880 a	5.168	225 ra
225 ra	β -	14.9 d	0.357	225 Ac
225 Ac	α	10.0 d	5.935	221 Fr
221 Fr	α 99.9% β - 0.1%	4.9 min	6.458 0.312	217 At 221 Ra
221 Ra	α	28.0 s	6.886	217 para
217 at	α 99.99% β - 0.01%	32.3 ms	7.202 0.740	213 Bi 217 Rn
217 para	α	0.54 ms	7,889	213 Po
213 bi	β - 97.91% α 2.09%	45.49 min	1.426 5.982	213 Po 209 Tl
213 Po	α	4.2 ms	8.537	209 Pb
209 Tl	β -	2.20 min	3,980	209 Pb
209 Pb	β -	3.253 h	0.644	209 bi
209 bi	α	1.9 · 10 19 a	3.137	205 Tl
205 Tl	-	stable	-	-

Individual evidence

1. ↑ Pierre de Marcillac, Noël Coron, Gérard Dambier, Jacques Leblanc & Jean-Pierre Moalic: "Experimental detection of α-particles from the radioactive decay of natural bismuth", in: Nature , 2003 , Volume 422, Number 6934, p. 876 -878; doi : 10.1038 / nature01541 .