Properties of water water isotopes. Naturally occurring water is almost completely composed of the neutron-less hydrogen isotope protium. Only 155 ppm include deuterium ( or D), a hydrogen isotope with one neutron, and fewer than 20 parts per quintillion include tritium ( or T), which has two neutrons. Oxygen also has three stable isotopes, with present in 99.76%, in 0.04%, and in 0.2% of water molecules. Deuterium oxide, , is also known as heavy water because of its higher density. It is used in nuclear reactors as a neutron moderator. Tritium is radioactive, decaying with a half-life of 4500 days; exists in nature
Radioactive Isotope Beam Factory atomic magic numbers. 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