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).

Radionuclides measured at PRIME Lab

Stable Isotope(s)RadionuclideHalf-Life (years)Detection Limit (10-15)
9Be 10Be 1,360,000 +/- 70,000 1
12C, 13C 14C 5,730 3
27Al 26Al 730,000 5
35Cl, 37Cl 36Cl 301,100 1
40Ca, 42Ca 41Ca 100,000 5
127I 129I 16,000,000 20