What are cosmogenic nuclides?
Cosmogenic nuclides are isotopes that are produced by interaction of cosmic rays with the nucleus of the atom. The cosmogenic nuclides measured by AMS at PRIME Lab are radioactive isotopes of the elements beryllium, carbon, aluminum, chlorine, calcium, and iodine. The lifetimes range from thousands to millions of years. They are produced in meteorites and other extraterrestrial materials, in the Earth's atmosphere, and on the solid surface of the earth.
The table below gives the half life (the time it takes for half of the atoms to decay) and the detection limit (value for the atom ratio of the radionuclide to stable nuclide measured for a "blank" sample that contains a negligable amount of the radionuclide).
| Radionuclide | Half-life (years) | Detection limit (10-15) |
|---|---|---|
| 10Be | 1,500,000 | 5 |
| 14C | 5,730 | 3 |
| 26Al | 730,000 | 5 |
| 36Cl | 301,000 | 1 |
| 41Ca | 100,000 | 5 |
| 129I | 16,000,000 | 20 |
