Radiation Protection Glossary

A radiation protection glossary for Radiation Protection Supervisors (RPS) and anyone interesting in radiation safety terminology. The glossary is a mixture of health physics terms, and phrases related to radiation legislation, transport, practical safety and similar.

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Positron

The positron has properties which are identical to those of a negatively charged Electron, except that it has a positive charge. Positrons are unstable in matter and disappear by Annihilation with negatively charged electrons. This produces two photons, each of 0.511 MeV which move in opposite directions. In simple terms positron emitters (e.g. O-15 and F-18) decay by a Proton changing into a Neutron and releasing a positron. One can say that the Nucleus of the parent has too much energy, but not enough to release an Alpha Particle and so releases a positron instead.

What's the matter? What's the antimatter? Does it antimatter?

– Wes Nisker