A367461 Number of beta-stable nuclides with neutron excess n, i.e., (neutron number) - (proton number) = n.

0, 0, 0, 0, 0, 0, 0, 2, 14, 17, 11, 5, 8, 8, 9, 3, 8, 5, 10, 9, 10, 5, 8, 4, 7, 1, 6, 2, 7, 4, 9, 6, 9, 5, 9, 2, 7, 3, 7, 5, 7, 3, 6, 5, 6, 2, 4, 4, 5, 2, 6, 4, 6, 5, 5, 3, 6, 3, 5, 4, 6, 4, 6, 3

Offset

-8,8

Comments

n = -8 represents the most proton-rich nuclide known (nickel-48). A beta-stable nuclide is a nuclide whose beta decay (beta-minus and beta-plus decay) is energetically disallowed; that is to say, a nuclide that has lower energy than its isobars with one more or one less proton. Note that double beta decay is allowed. A nuclide whose beta decay is energetially allowed, even if not observed (in the case of 48Ca, 96Zr, 123Te, 148Gd, 180mTa, 222Rn and 247Cm), is not classified as being beta-stable.

We know of 5 beta-stable nuclides with neutron excess 56 (244Pu, 248Cm, 252Cf, 256Fm, 260No), and it is almost sure that a(56) = 6 with the sixth beta-stable nuclide being the unobserved 264Rf.

Different from A318999: for Z <= 83, 5He, 8Be, 146Sm, 150Gd and 154Dy are beta-stable but not primordial. 40K, 48Ca, 50V, 96Zr, 113Cd, 115In, 123Te, 138La, 176Lu, 187Re and 180mTa are primordial but not beta-stable.

Prediction of a(56)-a(65) from a Russian source: 6, 3, 5, 3, 6, (2, 6, 6 or 3, 6, 5), 6, 3.

Prediction of a(56)-a(85) from pages 14-15 of the Hiroyuki Koura link: 6, 2, 6, 2, 6, 3, 7, 3, 7, 3, 7, 3, 8, 4, 8, 4, 6, 2, 5, 2, 5, 1, 5, 3, 6, 3, 6, 3, 7, 3.

Links

Table of n, a(n) for n=-8..55.

Hiroyuki Koura, Decay Modes and a limit of existence of nuclei, 4th International Conference on the Chemistry and Physics of the Transactinide Elements. (See here for an excerpted table.)

Web Archive, The Russian prediction for the continuation of the line of beta stability to the superheavy region.

Wikipedia, Beta-decay stable isobars.

Wikipedia, Isodiapher.

Wikipedia, List of beta-stable isodiaphers.

Example

a(17) = 1 because the only beta-stable nuclide with neutron excess 17 is 117Sn (Z=50, N=67). Note that neither 113Cd nor 115In is beta-stable.
a(22) = 9, with the last three being non-primordial.
a(23) = 6 because there are 6 beta-stable nuclides with neutron excess 23: 131Xe, 133Cs, 135Ba, 141Pr, 143Nd and 147Pm.
a(24) = 9.
a(25) = 5 because there are 5 beta-stable nuclides with neutron excess 25: 137Ba, 139La, 145Nd, 149Sm and 151Eu.
a(45) = 5 because there are 5 beta-stable nuclides with neutron excess 45: 213Po, 215At, 217Rn, 219Fr and 221Ra.
a(47) = 3 because there are 3 beta-stable nuclides with neutron excess 47: 223Ra, 225Ac and 227Th.

Crossrefs

Cf. A368859 (beta-stable isotopes), A368860 (isotones), A318999.

Sequence in context: A194379 A147832 A022369 * A278975 A096508 A355169

Adjacent sequences: A367458 A367459 A367460 * A367462 A367463 A367464

Keyword

nonn,hard,fini

Author

Jianing Song, Jan 26 2024

Status

approved