Actinide Alpha Decay Chains
| Actinides | Half-life | Fission products | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Cm | Puƒ | Cf | Ac№ | 10–22 y | m is meta |
Kr | Cd₡ | |||
| Uƒ | Pu | Cmƒ | 29–90 y | Cs | Sr | Sm₡ | Sn | |||
| ƒ for fissile |
Cfƒ | Amƒ | Cfƒ | 140 y – 1.6 ky |
No fission products |
|||||
| Am | Ra№ | Bk | ||||||||
| Pu | Th | Cm | Am | 5–7 ky | ||||||
| 4n | Cmƒ | Cm | Puƒ | 8–24 ky | ||||||
| Npƒ | Uƒ | Th№ | Pa№ | 32–160 ky | ||||||
| Cm | 4n+1 | U№ | 211–348 ky | Tc | ₡ can capture | Sn | Se | |||
| U | Np | Pu | Cmƒ | 0.37–23 My | Cs₡ | Zr | Pd | I | ||
| Pu | № for NORM |
4n+2 | 4n+3 | 80 My | 6-7% | 4-5% | 1.25% | 0.1-1% | <0.05% | |
| Th№ | U№ | Uƒ№ | 0.7–14 Gy | fission product yield | ||||||
In the four tables below, the minor branches of decay (with the branching ratio of less than 0.0001%) are omitted. The energy release includes the total kinetic energy of all the emitted particles (electrons, alpha particles, gamma quanta, neutrinos, Auger electrons and X-rays) and the recoil nucleus, assuming that the original nucleus was at rest. The letter 'a' represents a year.
In the tables below (except neptunium), the historic names of the naturally occurring nuclides are also given. These names were used at the time when the decay chains were first discovered and investigated. From these historical names one can locate the particular chain to which the nuclide belongs, and replace it with its modern name.
The three naturally-occurring actinide alpha decay chains given below—thorium, uranium/radium (from U-238), and actinium (from U-235)—each ends with its own specific lead isotope (Pb-208, Pb-206, and Pb-207 respectively). All these isotopes are stable and are also present in nature as primordial nuclides, but their excess amounts in comparison with lead-204 (which has only a primordial origin) can be used in the technique of uranium-lead dating to date rocks.
Read more about this topic: Decay Chain
Famous quotes containing the words alpha, decay and/or chains:
“Imagination is a valuable asset in business and she has a sister, Understanding, who also serves. Together they make a splendid team and business problems dissolve and the impossible is accomplished by their ministrations.... Imagination concerning the world’s wants and the individual’s needs should be the Alpha and Omega of self-education.”
—Alice Foote MacDougall (1867–1945)
“The goal of every culture is to decay through over-civilization; the factors of decadence,—luxury, scepticism, weariness and superstition,—are constant. The civilization of one epoch becomes the manure of the next.”
—Cyril Connolly (1903–1974)
“Habit is the ballast that chains a dog to his vomit.”
—Samuel Beckett (1906–1989)