CERN — the European Organization for Nuclear Research

Bubble chamber images

Product of CERN S'Cool LAB
bubble chamber image
bubble chamber image





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classroom acitivity, students can analyse bubble chamber tracks and learn more about particle identification


Dive into the fascinating world of bubble chambers and analyse tracks of high-energy particles with your students.

We have developed several activities for advanced high-school students, in which they study bubble chamber photographs and try to work out for themselves what they show. You can find a student worksheet describing these activities (including solutions and additional information for teachers) here: 

Suggestions for educators

  • Worksheet activity 1: How does a bubble chamber work? Students read a short text and learn about the different components of a bubble chamber.
  • Worksheet activity 2: Electrically charged particles in magnetic fields. Students apply the right-hand-rule to identify tracks of positively and negatively charged particles due to their track's curvature in magnetic fields.
  • Worksheet activity 3: Particle identification and properties. Students learn to distinguish tracks of different particles (electrons, "Compton electrons", positrons, and protons) and calculate the momentum of a given particle track.
  • Worksheet activity 4: Particle transformations. Students analyse the transformation of a pion.
  • Watch a demonstration of a superheated liquid produced by microwaving pure water, which is too dangerous for the classroom.
  • Watch a lecture by Don Glaser who won the 1960 Nobel Prize for Physics for his invention of the bubble chamber at Berkeley Lab. He discusses how, inspired by bubbles in a glass of beer, he invented the bubble chamber and detected cosmic-ray muons.  
  • Find out about recent dark matter detection experiments using bubble chambers from the PICO experiment website and the Fermilab website.
  • Bubble chamber art: Bubble chamber patterns also look great as seasonal decorations (e.g., made using the technique of paper quilling) or on dresses. What other creative ideas can your students come up with?
  • Online bubble chamber exercises: Find more advanced online exercises on Peter Watkins’s website.

Additional material

Read more about an easier version of this classroom activity in 'Science in School': Woithe, J., Schmidt, R., Naumann, F. (2019). Track inspection: how to spot subatomic particles, Science in School, 46

In French: Comment suivre les particules subatomiques à la trace

In Spanish: Análise da trajetória: Como identificar partículas subatómicas

In Italian: Alla ricerca delle traiettorie: come individuare le particelle subatomiche

Where can I find bubble chamber photographs?

The images used the activity we propose were produced by the 2 m-long bubble chamber at CERN in 1972. This chamber was filled with 1150 litres of liquid hydrogen cooled to 26 K (–247°C). The bubble chamber was exposed to a beam of protons from CERN’s proton synchrotron PS with a momentum of 24 GeV/c. Scans of the original photographs, as well as images with coloured tracks, can be found online:

Post date: Mon, Nov 18, 2019 — 22:31
Updated date: Tue, Jul 21, 2020 — 16:55

Learning Topics

Particle Identification