Cloud Chamber - Build and Observe a Particle Detector

Cloud Chamber

Description:  Students build their own particle detector using dry ice and isopropanol to make cosmic particles and natural radiation visible. Students study the properties of the different tracks and discuss their observations. 

Before taking part in this experiment, students should already know about

  • different types of particles, such as proton, neutron, electron, photon, helium nucleus ("alpha particle"),  (muon, positron, neutrino)
  • natural radiation (alpha, beta, gamma) and the different states of matter
  • ionisation and condensation (optional)

What students will learn: 

  • how a cloud chamber works and what kind of particles can be detected in a cloud chamber
  • where these particles come from


Link to CERN physics: The cloud chamber was used to discover the positron (Nobel Prize 1932) and the muon (Nobel Prize 1936). Today, cloud chambers are only used in education. However, the CLOUD experiment at CERN (Cosmics Leaving Outdoor Droplets) still uses a special cloud chamber to study the possible link between galactic cosmic rays and cloud formation. 



Minimum age: 14. For Open Cloud Chamber Workshops, participants as young as 12 are welome as long as they are each accompanied by an adult.

Age recommendation: 16 and above

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