CERN School: Klix.ba and BiH Teachers Build a Small Electron Detector

The First Bosnian-Herzegovinian Teacher Programme is currently taking place at CERN, and as part of the regular lectures and tours, a group of some 20 mathematics and physics teachers today had a very interesting experience – watching the effects inside a Wilson cloud chamber.

What is a Wilson cloud chamber? Put simply, it is one of the simplest particle detectors, cheap enough to be built in your own home.

Given that education in BiH is in such a poor state that even experiments like this rarely find their way into classrooms, some teachers saw for the first time, live, what this simple but striking scientific demonstration looks like and how it works. The Klix.ba reporter was equally impressed.

https://www.youtube.com/embed/_ySSVsm-Dsc
Video 1: The cloud chamber built by teachers from BiH

In a special section of CERN equipped for university and school students, called S'Cool LAB, a workshop was held that the participants of the First Bosnian-Herzegovinian Teacher Programme will not easily forget.

Using dry ice, surgical spirit, a rigid aluminium plate and a plastic container resembling an aquarium, our teachers managed in a very short time to create conditions that detect particles such as the electron or the muon, the electron's heavier sibling.

https://www.youtube.com/embed/LLeFaAdvn4I
Video 2: An advanced cloud chamber in the CERN museum

Essentially, leaving aside certain details, the dry ice is placed in the insulated base of the future detector, and the metal plate is laid on top of it. The plastic container has an absorbent material at its bottom, which is soaked in alcohol. It is placed upside down on the plate, creating a separate system that will soon be filled with condensed alcohol resembling fog.

Soon, unusual formations that appear and disappear relatively quickly will become visible in the fog clinging to the cold plate. These are in fact the tracks of particles which, as they pass through space, affect their surroundings enough for this to be visible to the naked human eye.

In the video below you can see how a cloud chamber is made, and at CERN our teachers were told that an even simpler version of the chamber is possible. All you need is, again, dry ice, but this time just a small pan, a plastic cup and an absorbent material for the surgical spirit, which you can buy at any pharmacy.

https://www.youtube.com/embed/xky3f1aSkB8
We advise younger science enthusiasts to leave carrying out these steps, as well as the explanations in the video, to their parents.

The Bosnian-Herzegovinian teachers, who came to Geneva from all parts of the country, continued the workshop by talking with the guides about what each phenomenon in the detector represents, how they are explained in relation to specific particles, and how they will take the knowledge of building simple detectors home and pass it on to their students.

The aim of the visit is to introduce teachers from BiH to current research in particle physics, and they will then pass on their experience to their students – the future physicists and engineers.

This cooperation was supported, in addition to CERN itself, by ANNT, the Association for the Advancement of Science and Technology.

Source: klix.ba