and more important to study the most exotic of radioactive nuclei. In order to do so, more inventive techniques are required to create nuclei with extreme proton/neutron ratios. An alternative to the ISOL techniques described here is that of fragmentation beams, where the radioactive ions are produced by fragmentation reactions on a fast beam of stable ions impinging on a thin target (usually of beryllium atoms). This technique is used, for example, at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University and at the Radioactive Isotope Beam Factory (RIBF) at RIKEN, in Japan. References External links Utilization of kinetic isotope effects for the concentration of tritium, GM Brown, TJ Meyer et al., 2001. Uranium Production Uranium Enrichment from the World Nuclear Association Annotated bibliography on electromagnetic separation of uranium isotopes form the Alsos Digital Library German inventions