Mesons are elementary particle which are strongly interacting bosons belonging to the hadron family. More than 140 different kinds of mesons are discovered by now. Mesons can be negatively or positively charged or neutral.

In cyclotrons charged particles are circular accelerated to bombard atoms. Short-lived positron-emitting isotopes are produced for Positron Emission Tomography (PET) imaging (e.g. F-18).

See also Linear Accelerator, Metastable Condition, Meson, Fluorodeoxyglucose, Electric Polarization.