Cloud Chamber build

materials

* 6 kg of dry ice
* An oven tray, preferably dark colored
* Gloves (To protect your hands from the Dry Ice)
* Isopropanol 99.9% pure 500 ml
* A big glass bowl, should be transparent
* A sponge, the kind I use to clean the kitchen
* 2 neodymium magnets
* The cover of the dry ice container
* A small peace of Thorium ore
* Lamp to make the vapor trails more visible (Ikea LED lamp can be used)

Some words on sourcing the materials

Since I built my cloud chamber in the Netherlands, this description is focused on sourcing the stuff in that location.
* The dry ice was sourced at Linde Gas, Linde Gas IceBitzzz
* Isopropanol 99,9% I sourced through through BRC international
* The 2 neodymium magnets where sourced from old hard drives.
* Piece of Thorium ore was bought from Ebay, with a bit of luck you can find a seller who will sell to customers in Europe.
* The light I used is the Ikea Jansjo
* For gloves, gloves from the DIY shop where used, nothing special.

How to build

Start by using the neodymium magnets to fix the sponge to the top of the bowl. Then make sure the sponge is saturated with isopropanol. Take the lid of the dry ice container place it with the inside facing up and fill the lid up with dry ice.
Lid upside down
Spread the dry ice evenly over the lid, so all areas have the same amount of dry ice. (same hight)
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Place the oven tray on top of the dry ice in the cover, and hold it down for about 30 seconds.
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Place a small peace of thorium ore in the middle of the oven tray. On top of the oven tray place the bowl (Upside down). Place the LED so that it shines at a shallow angle through the bowl.
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Watch the particles whizz through the isopropanol leaving trails.

Video of a piece of Thorium in the cloud chamber

Second video with the cloud chamber containing a piece of Fiesta ware (Left) and thorium (Right).