Isotope persisted down to the present because their rate of decay is so slow (e.g. uranium-238 and potassium-40). Post-primordial isotopes were created by cosmic ray bombardment as cosmogenic nuclides (e.g., tritium, carbon-14), or by the decay of a radioactive primordial isotope to a radioactive radiogenic nuclide daughter (e.g. uranium to radium). A few isotopes are naturally synthesized as nucleogenic nuclides, by some other natural nuclear reaction, such as when neutrons from natural nuclear fission are absorbed by another atom. As discussed above, only 80 elements have any stable isotopes, and 26 of these have only one stable isotope. Thus, about two-thirds
Radioactive Isotope Beam Factory Radioactive Isotope Beam Factory The Radioactive Isotope Beam Factory is a multistage particle accelerator complex operated by Japan's Nishina Center for Accelerator-Based Science which is itself a part of the Institute of Physical and Chemical Research. Located in Saitama, the RIBF generates unstable nuclei of all elements up to uranium and studies their properties. According to physicist Robert Janssens, ""[it] can produce the most intense beams of primary particles in the world."" RIBF took ten years to construct and its Superconducting Ring Cyclotron (SRC) can achieve energies of 2,600 MeV. Work at the RIBF has contributed to the understanding of