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
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
- ↑ 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 .