Cloud Chamber: Introduction

Did you know that there are particles moving around you right now? Some you can see, while others you cannot. I want to be able to “see” these invisible particles. I won’t be able to hold them in place, and analyze them, but I will be able to see their trails.

Now, this is seemed impossible at first. Even if it were possible, it would be very confusing. After some research into the invisible particles, I found their scientific name – ionizing particles. They are mostly known as alpha particles, beta particles, and gamma particles. They are electrically charged particles, gaining or losing one of their electrons through a process called ionization.

After I found what I was looking for, I needed to find a way to see them. Once I moved past the multi-million dollar tools that were apparently outside of the i2 budget, I found the very first tool ever made for this purpose. It is called a cloud chamber. The basic idea behind it is that: at the bottom, there is a cold plate at around -14℉. Within a clear enclosure (so that you can see the particles), there is a high content alcohol, around 90%. As the alcohol wants to be a gas at the top (it evaporates at room temperature), but a liquid at the bottom, the container becomes supersaturated, almost a liquid. Essentially, the alcohol is still a gas, but the alcohol atoms are closer together, creating a bigger target for the aforementioned particles.

As more time passes, and particles ‘hit’ the alcohol, they leave trails. Based on the particles’ ionization, they leave different sized trails. Alpha particles are the largest, and will leave the biggest trails, with gamma particles leaving the smallest ones. As I start testing the cloud chamber, I will be able to photograph and compile different trials.

To build the cloud chamber, I turned to YouTube. Many people have made the chamber with a clear plastic cup and dry ice, but I wanted to go bigger. I want an acrylic box about the size of a desk, cooled by peltier devices. Peltier devices, also known as thermoelectric cooling devices, use electricity to cool one of their sides, heating the opposite. I could easily do this project with dry ice, and I will build it with the capability of dry ice. But, I want to use a technology that I have only heard about. As this project continues, and my research deepens, I will show my findings. Will I use dry ice? Are peltier devices the future? How well do they work?