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The primordial nuclide total listed here (289) does not match that given elsewhere in wikipedia i.e. at Primordial Nuclide (288). The EE value there is 169. I think that U-234 was accidently included here. The next long lived nuclide after Pu-244 (82My) is Nb-92 (37My). This should be the 289th primordial nuclide. U-235 has only a 245ky half life. The tables at the start and end of the article also need fixed to show 288 total primordial nuclides. 99.32.172.114 (talk) 05:23, 14 April 2013 (UTC)
Fissile nuclides tend to have even Z and odd N. This is very important and should perhaps be more prominently stated in the article.
Looking for better sources. Andrewa (talk) 04:07, 6 February 2024 (UTC)
For some odd-odd nuclides, beta decay and/or IT requires high spin change. For the following nuclides, a such decay process is at least 3 forbidden non-unique or 4 forbidden unique. The states are taken from:
https://www.nndc.bnl.gov/nudat3/getdataset.jsp?nucleus=X&unc=NDS, where X is a nuclide symbol (for example https://www.nndc.bnl.gov/nudat3/getdataset.jsp?nucleus=50V&unc=NDS);
If the link does not work, an alternative is
https://www.nndc.bnl.gov/ensnds/M/X/adopted.pdf, where X is an element name and M is a mass number (for example https://www.nndc.bnl.gov/ensnds/50/V/adopted.pdf).
Nuclide | QITmax (keV) | QECmax (keV) | Qβ−max (keV) | Possible IT processes | Possible EC processes | Possible β− processes |
---|---|---|---|---|---|---|
50V | - | 2204.9 | 1037.9 | - | 6+→0+ (ΔJΔπ = 6+), 2204.9 6+→2+ (ΔJΔπ = 4+), 651.1 |
6+→0+ (ΔJΔπ = 6+), 1037.9 6+→2+ (ΔJΔπ = 4+), 254.6 |
180mTa | 77.2 | 929.4 | 785.5 | 9−→1+ (ΔJΔπ = 8−), 77.2 9−→2+ (ΔJΔπ = 7−), 37.7 |
9−→0+ (ΔJΔπ = 9−), 929.4 9−→2+ (ΔJΔπ = 7−), 837.0 9−→4+ (ΔJΔπ = 5−), 620.8 9−→6+ (ΔJΔπ = 3−), 288.6 |
9−→0+ (ΔJΔπ = 9−), 785.5 9−→2+ (ΔJΔπ = 7−), 681.9 9−→4+ (ΔJΔπ = 5−), 447.9 9−→6+ (ΔJΔπ = 3−), 97.0 |
210mBi | 271.3 | 207.8 | 1432.6 | 9−→1− (ΔJΔπ = 8+), 271.3 9−→0− (ΔJΔπ = 9+), 224.8 |
9−→0+ (ΔJΔπ = 9−), 207.8 | 9−→0+ (ΔJΔπ = 9−), 1432.6 9−→2+ (ΔJΔπ = 7−), 251.2 9−→4+ (ΔJΔπ = 5−), 5.9 |
214mAt | 231.0 | 1321.4 | 1170.9 | 9−→1− (ΔJΔπ = 8+), 231.0 9−→0− (ΔJΔπ = 9+), 153.0 9−→2− (ΔJΔπ = 7+), 85.9 9−→3− (ΔJΔπ = 6+), 44.0 9−→4− (ΔJΔπ = 5+), 2.9 |
9−→0+ (ΔJΔπ = 9−), 1321.4 9−→2+ (ΔJΔπ = 7−), 712.1 9−→4+ (ΔJΔπ = 5−), 306.3 9−→3− (ΔJΔπ = 6+), 46.6 |
9−→0+ (ΔJΔπ = 9−), 1170.9 9−→2+ (ΔJΔπ = 7−), 476.1 9−→4+ (ΔJΔπ = 5−), 29.7 |
103.166.228.86 (talk) 15:29, 15 April 2024 (UTC)
Look at the level diagram (in keV) of some decay products:
Nuclide | 0+ → 2+ | 2+ → 4+ | 4+ → 6+ | 6+ → 8+ | 8+ → 10+ | 10+ → 12+ | 12+ → 14+ |
---|---|---|---|---|---|---|---|
176Hf | 88.35 | 201.83 | 306.64 | 400.91 | 483.33 | 553.60 | 611.94 |
236U | 45.24 | 104.24 | 160.31 | 212.47 | 260.14 | 303.00 | 341.00 |
236Pu | 44.6 | 102.8 | 158.4 | 209.9 | 257.8 | 300.8 | 339.3 |
248Cm | 43.4 | 100.4 | 155.1 | 207.5 | 256.4 | 301.3 | 342.1 |
248Cf | 41.5 | 96.3 | 149.6 | 200.6 | 249.5 |
These levels are separated by units of spin, and their energies get further apart as the spin increases. That's a classic sign of collective nuclear rotation, with a rigid rotor having kinetic energy . On the other hand, the high spins of 176Lu, 236Np, and 248Bk are intrinsic, so the decay processes must overcome a terrible match even if the spin change is low. Their β decay information:
Decay process | Qβ (keV) | Spin change | Half-life (a) | Intensities taken from |
---|---|---|---|---|
176Lu → 176Hf | 593.33 | 7− → 6+ (ΔJΔπ = 1−, 1 forbidden non-unique) | 3.72×1010 | [2] |
192.49 | 7− → 8+ (ΔJΔπ = 1−, 1 forbidden non-unique) | 9.49×1012 | ||
236Np → 236U | 783.52 | 6− → 4+ (ΔJΔπ = 2−, 1 forbidden unique) | unknown (at the order of 108?) | [3] |
623.21 | 6− → 6+ (ΔJΔπ = 0−, 1 forbidden non-unique) | 1.78×105 | ||
85.40 | 6− → 5− (ΔJΔπ = 1+, allowed) | 1.55×108 | ||
236Np → 236Pu | 329.15 | 6− → 4+ (ΔJΔπ = 2−, 1 forbidden unique) | unknown (at the order of 109?) | [4] |
170.80 | 6− → 6+ (ΔJΔπ = 0−, 1 forbidden non-unique) | 1.29×106 | ||
248Bk → 248Cm | 388.07 | 6+ → 6+ (ΔJΔπ = 0+, allowed) | unknown (at the order of 107?) | |
248Bk → 248Cf | 552.01 | 6+ → 6+ (ΔJΔπ = 0+, allowed) | unknown (at the order of 106?) |
On the other hand, the longevity is probably not applicable to the unknown decay processes 212mAt → 212Po (9− → 8+, QEC = 271.84 keV) and 216mAt → 216Rn (9− → 8+, Qβ− = 517.68 keV), because the high spin of 212Po and 216Rn does not seem to be a result of collective nuclear rotation, as their level diagrams are irregular:
Nuclide | 0+ → 2+ | 2+ → 4+ | 4+ → 6+ | 6+ → 8+ | 8+ → 10+ | 10+ → 12+ | 12+ → 14+ |
---|---|---|---|---|---|---|---|
212Po | 727.33 | 405.18 | 222.98 | 120.90 | 357.50 | 868.34 | 183.17 |
216Rn | 461.4 | 379.1 | 385.4 | 419.1 | 294.7 | 465.9 | 420.5 |
It should be pointed out that, although not specified, it seems that 212mBi → 212Po (9− → 8+, Qβ− = 775.11 keV) is known, as shown in the last diagram of here. 129.104.241.193 (talk) 15:10, 7 May 2024 (UTC)