Make a Cloud Chamber using Peltier Coolers

Step 17 Using the Chamber

Place your radioactive sample inside the cloud chamber.

Add about 1 teaspoon of alcohol to the sponge.

Put the top on the container.

Plug in both power supplies.

Hold the LED flashlight behind the chamber.

Within a minute or two you should be able to see a fine mist covering the bottom 1/8th inch or so of the container.

Try changing your viewing angle / flashlight position to best see the mist.

Rub the styrofoam cup (or other static thingy such as a balloon) in your hair - then place it over the container.

Within 2-10 minutes - you should start seeing vapor trails from the radiation!

IMPORTANT: "Recharge" the styofoam cup / balloon (rubbing it in your hair) periodically.  Try removing it / repositioning it to see what provides the best visibility of radiation trails.  This is key to being able to see alpha particles!

If you don't see trails - revisit the troubleshooting section in step 16.

Performance may improve as things cool.

Comments

[neimad]

 So far I have not read anywhere a mention of what type of alcohol to use. I'm sure this is probably an important detail. Some people may not know exactly what to use.  Can you please include what type of alcohol to use for best results?  

[joseph.raul1]

One other thing you can try is to "salt out" standard isopropyl alcohol to get 99% purity:

http://www.instructables.com/id/How-to-Salt-Out/

I did this today and it works as the alcohol separates to the top while the salt stays on the bottom.  Only drawback is that the resulting alcohol may contain traces of salt. 

[nothinglabs]

check step 2 - it's in there.

if you can't find 99% isopropyl - I'd try "denatured alcohol" (which is ethyl)

joseph seems to be getting pretty solid results with 91%.

I wouldn't bother trying 70% (tried it sometime ago - didn't work well at all)

you can also try "everclear" - if they have that at your liquour store.