What’s the difference between sodium-22 and sodium-23?
One is edible (sodium-23) and the other is radioactive. Such differences are the superpowers of isotopes—variants of an element that have the same number of protons but differ in the number of neutrons. Chemical properties of isotopes of the same element are generally similar, but their physical properties can vary.
Some isotopes, such as sodium-23, occur naturally, but others are created using nuclear reactors or accelerators. In an accelerator, particles (such as protons) are accelerated to high speeds and used to bombard a target, which causes a nuclear reaction that produces isotopes. Scientists can tailor the type of particles and the type of target to create specific isotopes.
One such accelerator, located at the Los Alamos Neutron Science Center (LANSCE) at Los Alamos National Laboratory, is used to produce isotopes for a range of scientific, medical, and industrial applications.
At LANSCE’s Isotope Production Facility, scientists make isotopes to order for the Department of Energy (DOE) Isotope Program, which coordinates with hospitals and companies around the country to determine what to produce and when. DOE’s national laboratories work together under the Isotope Program’s direction to ensure a steady supply of critical isotopes. These isotopes are used for medical, national security, environmental, and industrial applications. ★
Los Alamos–produced isotopes (some of many):
- Americium-241: used in smoke detectors and for oil and gas exploration
- Arsenic-73: used for environmental research
- Cadmium-109: used to calibrate instruments that monitor air quality
- Sodium-22: used as a source for positron emission tomography
- Additional isotopes are produced on demand
