Make a Cloud Chamber using Peltier Coolers

Step 13 Attach the Sponge to the Container's Top

Drill a hole in the top of the container for the bolt.

Poke a small hole in the sponge using a pencil.

Use the nut and bolt to attach the sponge to the inside top of the container.

Don't worry about the seal not being perfect. A small leak at the top of the chamber won't hurt performance.

Comments

[fightthemachine]

Could you provide more details on this step?

Does the bolt and sponge need to be air or particle tight, or at least close to slow the evaporation of the alcohol down and aid the process in the chamber? ... Or is it to allow fresh air to sneak in around the threads?

Just a little nervousness regarding nuclear leaks and vaporization reactions in a small apartment downtown Metropolis... or the mention of radiation puts a fear of zombies into the night air.

[nothinglabs]

does not need to be perfect / air-tight.  leaks at the bottom of the chamber are bad - leaks at the top aren't really a problem (can even run the chamber with the lid a little off)

I'm not going to suggest you ignore concerns about radiation - but if you're buying something on ebay - it's probably not that dangerous (just wash your hands after touching - and don't eat it)

[fightthemachine]

Will it affect/harm little kids, kittens or houseplants if used too long or allowed to radiate?

[nothinglabs]

you can always build it without using a radiation source - and then see the periodic cosmic ray.

from a radiation standpoint - this project isn't any better / worse than the radioactive source. 

biggest safety hazard is probably plugging the coolers in backwards - then starting a fire. 

[fightthemachine]

I'm not concerned for radiation, more air quality in a small stuffy apartment or in a garage downtown, I would love to show off the reaction, just without combustion of alc or sparking reactions getting the landlord involved, he gets more nervous than I am regarding particle physics lol.