I Positron discovery in cloud chamber, how so?

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The discussion centers on the discovery of positrons in a cloud chamber, highlighting the concern that positrons should annihilate upon encountering electrons. It is clarified that positrons have a very short lifetime of about 10^-10 seconds within matter, which allows them to be detected before annihilation occurs. The use of a magnetic field in cloud chambers enables the observation of distinct trails for electrons and positrons, facilitating energy measurements. The conversation references educational resources that enhance understanding of these concepts. Overall, the mechanics of positron detection in cloud chambers are explained through their interaction with magnetic fields and the brief existence of positrons.
DaTario
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Hi All,

I was watching a video from Veritassium () when it was said that positron discovery was made in a cloud chamber. If the anti-particle of the electron is passing through a dense cloud of atoms and molecules, won't it be natural for this anti-particle to meet an electron and go through a fast pair anihilation, giving rise to photons?

Best wishes

DaTario
 
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IIRC, our school's cloud-chamber had an optional magnetic field via a pair of coils. Trails from the 'source' spiralled one way for electrons, other way for their anti-kin. And, if you were quick, measurement of curl's diameter allowed a useful estimate of energy etc...

Our school had a 'Treasure Trove' of Nuffield teaching equipment, akin to 1st-year Uni Physics level...
 
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