The first particle detector
Cloud chambers are setup in a way such that any charged particle passing through will
leave behind a trail. Typically this is done by permeating the space with a gas in a supercritical state,
such that any charged particle will ionise and reliquify the gas to form droplets.
In the absence of an radioactive sources, cloud chambers detect cosmic rays and their products from cosmic
showers. By placing the cloud chamber in a magnetic field, the particles' mass and charge reveal themselves
through the radius of its cycloidal motion. This is how the first anti-particle was discovered when Blackett
and Anderson saw an electron veering in the wrong direction! Cloud chambers also discovered the muon and
the anti-muon.
In particular, the electron has mass \(m_e\simeq 0.5\,\mathrm{MeV}\) while
the muon has \(m_{\mu}\simeq 100\, \mathrm{MeV}\). What does this tell us about their trajectory's radius in
the chamber? (Hint: Think radially!)
This project started with me wanting to build my own cloud chamber for cheap, for example as showcased in
this video. I realised it would be a challenge (and also free) to
just code one up and let people play with a limited version themselves.
Over time I might implement cooler features such as decay/pair creation, or an interactive quiz.
If you have some relevant programming experience, feel free to send me suggestions about how you would render these animations.
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Select magnetic field
\(\bigodot\)
\(\bigotimes\)
off
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Select particle type
\(p\)
\(\mu^{-}\)
\(e^{-}\)
\(\alpha\)
\(\mu^{+}\)
\(e^{+}\)
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showing gif:
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