The most commonly used spontaneous fission neutron source is the radioactive isotope californium-252. The chemical symbol for Californium is Cf.Ĭalifornium is an actinide element, the sixth transuranium element to be synthesized, and has the second-highest atomic mass of all the elements that have been produced in amounts large enough to see with the unaided eye (after einsteinium).
Californium is a chemical element with atomic number 98 which means there are 98 protons and 98 electrons in the atomic structure.