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Q:
if positrons are emitted during decay, why dont they interact with electrons and annihalte? and if they do, why dont we see flashed of light coming out from banannas when potassium turns to potassium 40 and emits positrons?
- andrew (age 28)
lansdale pa
A:
The positrons do pretty quickly annihilate with electrons. However, the energy released is ~500keV per particle, so the resulting gamma rays are far from the visible range.
The annihilation process and its output is described here:
http://en.wikipedia.org/wiki/Positron_emission_tomography .
Mike W.
(published on 01/10/2012)
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