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Cloud Chamber Workshop
BUILD YOUR OWN CLOUD CHAMBER AT HOME
Particles coming from the universe (cosmic rays) are crossing the
earth all the time – they are harmless but invisible to us, also called
natural radiation. Cloud chambers are detectors to make the tracks
of the particles visible. Some decades ago – these detectors were
used at CERN in the first experiments to detect particles. Wouldn’t
it be nice to build such a detector at home in your kitchen? We
show you how to build a small one at home in your kitchen for your
own research ....
Shopping list
• A clear, see-through box-like plastic container, with flat sides and
an open top, roughly 20 x 30cm (open side) x 15cm (height)
• A metal plate (at least 5mm thick) to cover the open size of the
container completely (plate must be a little bit larger than the
box). The plate should be preferably black and should have a
little grooves matching the side walls of the plastic box. As this is
probably hard to find, you can also use a flat metal plate and use
black electrical tape to make the metal plate surface black.
• A thick felt (few mm), a bit smaller than the bottom of the box.
• 4 clips (self-adhesive cable-tie holders + cable ties) to attach the
felt to the inside of the bottom of the box
• A small wooden box that is just a little bit larger in area than the
metal plate and approx. 5cm in height. The box later on has to
take the ice plates and the metal plate but the sides should not
be much higher so that it doesn’t cover the plastic box.
• A very intense, bundled light source, e.g. a slide projector, strong
flashlight ...
• Pure (not 70%) isopropyl alcohol – make sure you get the right
one – it will only work well with this one it and keep it out of reach
of children).
• Dry Ice (Careful with your hands – always use thick gloves and
never touch the ice directly! The ice is at -78oC; touching it
directly will give you a burn.)
• Security goggles to handle the ice
• Gloves to handle the ice and the alcohol
A word o