Radiation. When I say that word, what do you think of? … A chuck of glowing green crystal that melts you in seconds when you touch it, or are even close to it like the Ark of the Covenant from Indiana Jones? Well, probably not, but it is a mysterious and dangerous force that you don’t often encounter. But what if I told you that it is possible that the very dinner-plates that you eat off of could have Uranium in the paint that gives off constant radiation? Well, in our last FSL session we decided to do a physics demonstration to show how a specific type of radiation works, called Beta (ß) radiation. Here it is.
CLOUD CHAMBER RADIATION LAB
To demonstrate how beta radiation works, and how it reacts with the world.
Procedure & Materials:
- Place cotton ball on bottom of clear plastic drinking cup.
- Secure the cotton ball with 2 neodymium magnets, inside and outside.
- Acquire a palm-sized petri dish, and cover the inside portion with a layer of black tissue paper.
- Pour Isopropyl alcohol onto cotton ball until it is partially soaked.
- Fill a Styrofoam bowl with dry ice.
- Put a radioactive material in center of petri dish, onto of tissue paper (in our case, we used a very old chunk of bright orange “Fiesta” dinnerware, which has paint containing Uranium Oxide)
- Secure upside-down plastic drinking cup over top of petri dish, seal the cup as much as possible, using tape or play-dough
- Place petri dish on directly on top of dry ice.
- Turn off lights and use a flashlight to observe the experiment.
After some time, a fine mist formed inside of cup and is visible near bottom of cup, above petri dish.
Rarely, thicker bands of mist would form, originating from the radioactive substance. This was beta particles interacting with the alcohol droplets.
- Seal the cup setup better
- Get a more radioactive element, so that you are more likely to see a particle.
- Make the setup wider, so that it is more likely to see a decaying beta particle or the rotation of the particle.
- Use a more specific light, like a laser so that it is easier to see the mist.
- (Not sure) – Crush up the dry ice to increase surface area and reduce temperature, or use liquid nitrogen, however, I am not sure how effective this would be.