If you’ve been watching Oppenheimer and it’s gotten you all excited about the idea of radioactive decay, you might want to visualize it. A cloud chamber is the perfect way to do that, and [NuclearPhoenix] is here to show us just how to build one.
The build relies on a Peltier device to cool a 10 cm square copper plate down to temperatures as low as -30 °C (-22 °F). Isopropyl alcohol is evaporated via warming resistors within the cloud chamber, and then condenses in the cooled area, creating a thin layer of fog. Ionizing radiation that passes through the chamber can then be spotted by the the trails it leaves through the fog. It’s even possible to identify the type of radiation passing through by the type of trail it leaves. Alpha particles leave shorter traces, while more energetic beta particles which are difficult to stop tend to streak further.
It bears noting that if you see a ton of activity in your cloud chamber at home, it might be worth making some enquiries. Some cloud chambers you’ll see in museums and the like use a small radioactive source to generate some excitement for viewers, though. Video after the break.
I’ve always loved these things, ever since I was a kid.
It’s a bar of soap placed in fog generator??? Abstract art??? I don’t get it.
Try reading the words above the video? It’s a scientific instrument for seeing ionising radiation.
An excellent radioactive source is americium 241 from an ionization smoke detector. Search on Ebay “Ion Chamber Metal Geiger Counter Check Test Source Smoke Detector Sensor NAP-07”.
Additionally, you can get radioactive ore samples on eBay and United Nuclear. Search for pitchblende, thorite, or “radioactive ore”, or geiger counter tester.
You can get uranium glass on eBay, and probably from many other sites and probably from the local antiques store. uranium glass was very popular in the day.
Also, you can get replacements for glowing watch hands, which were painted using uranium salts, and are so radioactive that if you get a paper card containing 20 hands, there are scorch marks next to each hand.
I think Radium (Ra-226)- and Promethium (Pm-147)-containing luminous paints were used until the 1960s, and tritium-enriched paints until the mid-1990s. Never heard of Uranium salts paints.
I believe mantles for propane powered lanterns are also mildy radioactive.
Yes you are correct, it’s thorium on the original Coleman ,alladin lamp mantles
Some welding rod tips also contain thorium. Another possibility would be Uraninite, which you can buy at mineral fairs, for example or Uranium glass.
My son and I built one last year:
https://www.reddit.com/r/instructables/comments/v98ank/i_made_a_thermoelectric_cloud_chamber_with_my_son/?utm_source=share&utm_medium=web2x&context=3
Ours uses 4 2 stage peltier and is water cooled.
https://www.reddit.com/r/interestingasfuck/comments/xql5pn/my_son_and_i_built_a_cloud_chamber_particle/?utm_source=share&utm_medium=web2x&context=3
Very, very impressive!
It would be nice to add a strong magnet, to curve the tracks of the charged particles.
Indeed. A challenge would be to design a coil that provides a uniform magnetic field of known strength across the visible portion of the chamber. This would allow estimation of the energy of individual particles based on the observed curvature of their path.
“If you’ve been watching Oppenheimer”
I’ve not. Here’s why…
This movie omits the unnecessary and evil bombings of Hiroshima and Nagasaki and also of its testing ground in New Mexico and the Marshall Islands as if there were no innocent victims and grave harm done (https://www.themarysue.com/oppenheimer-has-people-speaking-out-about-a-pretty-glaring-omission) which shows the lack of conscience of its creator/filmmaker/director. And that this immoral director presents a whitewash of history, it’s a fake history account. Memory holing of real atrocities is immorality, a serious crime per any reasonable humane standard. But it is in line with what it is: a propaganda movie of the genocidal US empire, made by its criminal Hollywood ‘dream factory’/propaganda apparatus.
This inexcusable despicable conduct by the film’s acclaimed director parallels the fact that dozens of Nobelists worked on the creation of the atomic bomb proves that guilt and conscience never played a notable part in them.
Oppenheimer’s guilt and conscience, too, was of no real significance as his actions in establishing the atomic bomb demonstrated.
It shows the real fundamental condition and nature of “civilized” humans — they are inhumanely mad …. https://www.rolf-hefti.com/covid-19-coronavirus.html
“[…] I realized that the entire nuclear power program was based on a fraud—namely, that there was a “safe” amount of radiation, a permissible dose that wouldn’t hurt anybody.” — John W. Gofman, M.D., Ph.D., 1918-2007, Medical Physicist