Positron Interactions With Matter

Most recent answer: 03/19/2015

Do positrons always annihilate when they come in contact with ordinary matter at lower energy states?
- Peter (age 53)

Hello Peter,

Positrons can do one of several things when interacting with ordinary matter: 

Scatter elastically from an atom with hardly any loss of energy

Scatter inelastically from an atom leaving the atom in an excited state

Annihilate with an electron in an atom and emit two photons. 

The probabilities of these possible outcomes vary considerably with the incident positron energy.

There is a raft of information on positron-matter interactions on the web; just google positron interactions with matter.


Lee H.


(published on 03/19/2015)