Fission reactors and cyclotrons tend to produce different kinds of isotopes. A reactor produces isotopes primarily through neutron activation; thus, the isotopes tend to be neutron-rich (high neutron-to-proton ratio). A cyclotron can only accelerate charged particles such as protons or deuterons. When stable nuclei are bombarded with protons or deuterons, the resulting radioisotopes are neutrondeficient (low neutron-to-proton ratio).
(a) Explain why a cyclotron cannot accelerate neutrons.
(b) Suppose a hospital needs a supply of radioisotopes to use in positronemission tomography (PET). Would the radioisotopes more likely come from a reactor or a cyclotron? Explain.