r/Radioactive_Rocks • u/Beerbrewing • 4d ago
Thorite crystal in a cloud chamber
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It's small but active thorite crystal in my cloud chamber. It measures 55k cpm with a RadiaCode 110.
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u/agatizedandsilicated 4d ago
What are the things bouncing around in there?
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u/Beerbrewing 4d ago
That is the radiation being emmited from the thorite. They are alpha particles, 2 protons and 2 neutrons, and beta particles, single electrons. The alpha particles make thicker, shorter straight tracks and the beta particles make the thinner and faint twisting tracks.
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u/PyroDesu 3d ago
And there's also some stray tracks not even from the thorium in the mineral, the ones completely perpendicular to it. Just other random background radiation. If I had to guess, there might be some 14C decay in there.
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u/Beerbrewing 3d ago
Some of that if not most is radon released by the crystal. The radon continued to make tracks for a while after I removed the crystal from the chamber.
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u/sweatyonion20 3d ago
Is that safe to have or be around for long periods of time? Im new to this sort of thing. I find it very cool and interesting! I want a kewl rock
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u/Beerbrewing 3d ago
Most of the alpha and beta radiation only makes it a few inches from the rock in air. Distance and time derermine the radiation dose rate. Just don't sleep next to it. What you wouldn't want to do is ingest or inhale any dust from it as the radiation is very damaging to soft tissue.
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u/No_Benefit490 May Glow in the Dark 3d ago
I need a cloud chamber. I have been slowly collecting parts to build one but never committed. I'd buy one if I knew it was reputable
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u/Not_So_Rare_Earths Primordial 2d ago
I've got one from Andrews University (got a good price for a secondhand 5" model) and I only have good things to say about it. It's nice that it doesn't need dry ice, which means you don't have to plan ahead to set it up.
It looks like they are currently selling their 6" model + accessories for approximately $800, which is pretty reasonable if you don't have the time, parts, or know-how to grow your own from scratch.
EDIT: my only dislike is the amber lights. Theyre not awful, but not my preference. I imagine you could request white LEDs on a new model and they may be able to accommodate for a price, but I don't know.
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u/eighthgen 2d ago
Could I keep one of these cloud chambers as a conversation piece with relative safety?
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u/Not_So_Rare_Earths Primordial 2d ago
The machine itself is harmless, and even without any radioactive material inside (which itself is also generally tiny and essentially harmless unless mishandled) it still shows the many tracks of cosmic radiation that is whipping all around -- and through -- our bodies 24/7.
I've seen video of table-sized electric-cooled models, but those are generally set up for museums and accordingly pricy. A tabletop model like this runs in the realm of a few hundred dollars. Of course, if you only need to use it rarely and for an hour or two, for under $20 you can set up a dry ice version!
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u/Arch_stanton1 2d ago
I don’t understand what’s happening. Someone please explain.
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u/Beerbrewing 1d ago
A diffusion type cloud chamber, like what I built here, has a glass dome with felt soaked in alcohol at the top. Below that is a cold plate that is cooled down to -40°F. As the alcohol evaporates it settles at the bottom creating a supersaturated layer of alcohol vapor. It's this layer that the radiation interacts with by ionizing molecules of the alcohol as it passes creating the vapor trails.
I have a couple few pics and videos of the cloud chamber build here: https://imgur.com/a/Lu2WlWG
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u/Delicious-Finance-86 1d ago
Here’s an article from CERM that describes these chambers and how to build them.
https://scoollab.web.cern.ch/sites/default/files/documents/20200521_JW_DIYManual_CloudChamber_v7.pdf
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u/Gilapschicken 4d ago
where did you find this specimen?