THE GREAT PROMISE OF ISOTOPES
The world around us is made of atoms, comprising the periodic table of elements. Many elements have multiple isotopes, which only differ by the number of neutrons in the nucleus. These isotopes can occur naturally, with varying relative abundances. They can also be made artificially, leading to short-lived radioisotopes.
A LOOMING SHORTAGE OF ISOTOPES
The starting point for isotope separation is the Calutron; it was developed in 1930 by Ernest Lawrence as a machine that can separate stable isotopes of the elements. The Calutron was combined with the parallel development of the ability to transmute stable isotopes into radioisotopes. Ironically, although the Calutron was invented in the US, the only remaining operational large-scale machines are in Russia, and even those were built over 60 years ago.
We are facing a looming crisis in the supply of a wide range of isotopes. Recent reports by the U.S. Government Accountability Office and the U.S. Nuclear Science Advisory Committee to the Department of Energy alert to impending shortages. The almost total dependence on Russian machines creates a very fragile supply chain, especially in light of their extreme age, operating expense, and geopolitical tensions. This creates an urgent need for a new domestic and efficient method for isotope production.
Isotopes are a great resource for humanity. In medicine, therapy with radioactive seeds shows great promise in treating tumors. Radio-immunotherapy, where cancer cells are directly targeted and destroyed, may provide a long-sought cure for certain forms of cancer. Medical imaging with radioisotopes provides diagnosis of illness. Stable isotopes can be used as tracers for metabolism of minerals crucial for our health. It is clear that we are just on the threshold of finding many exciting new uses of isotopes that will benefit our lives.