Absolute dating radiocarbon dating. The development of accelerator mass spectrometry (AMS) dating, which allows a date to be obtained from a very small sample, has been very useful in this regard. Other radiometric dating techniques are available for earlier periods. One of the most widely used is potassium–argon dating (K–Ar dating). Potassium-40 is a radioactive isotope of potassium that decays into argon-40. The half-life of potassium-40 is 1.3 billion years, far longer than that of carbon-14, allowing much older samples to be dated. Potassium is common in rocks and minerals, allowing many samples of geochronological or archeological interest to be dated. Argon,
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