See The Radioactive World With This Peltier Cloud Chamber

January 13, 2019 by 17 Comments

Remember when a homemade cloud chamber was a science fair staple? We haven’t participated for decades, but it seemed like every year someone would put a hunk of dry ice in a fish tank, add a little alcohol, and with the lighting just right – which it never was in the gymnasium – you might be lucky enough to see a few contrails in the supersaturated vapor as the occasional stray bit of background radiation whizzed through the apparatus.

Done right, the classic cloud chamber is a great demonstration, but stocking enough dry ice to keep the fun going is a bit of a drag. That’s where this Peltier-cooled cloud chamber comes into its own. [mosivers] spares no expense at making a more permanent, turn-key cloud chamber, which is perched atop a laser-cut acrylic case. Inside that is an ATX power supply which runs a Peltier thermoelectric cooling module. Coupled with a CPU cooler, the TEC is able to drive the chamber temperature down to a chilly -42°C, with a strip of white LEDs providing the required side-lighting. The video below gives a tour of the machine and shows a few traces from a chunk of pitchblende; it’s all pretty tame until [mosivers] turns on his special modification – a high-voltage grid powered by a scrapped electronic fly swatter. That really kicks up the action, and even lets thoriated TIG welding electrodes be used as a decent source of alpha particles.

It’s been a while since we’ve seen a Peltier cloud chamber build around here, which is too bad because they’re great tools for engaging young minds as well as for discovery. And if you use one right, it just might make you as famous as your mother.

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Open Source Cloud Chamber

June 11, 2016 by 14 Comments

If you are a certain age, there were certain science toys you either had, or more likely wanted. A chemistry set, a microscope, a transparent human body, and (one of several nuclear toys) a cloud chamber. Technically, a Wilson cloud chamber (named after inventor Charles Wilson) isn’t a toy. For decades it was a serious scientific tool responsible for the discovery of the positron and the muon.

The principle is simple. You fill a sealed chamber with a supersaturated water or alcohol vapor. Ionizing radiation will cause trails in the vapor. With a magnetic field, the trails will curve depending on their charge.

If you didn’t have a cloud chamber, you can build your own thanks to the open source plans from [M. Bindhammer]. The chamber uses alcohol, a high voltage supply, and a line laser. It isn’t quite the dry ice chamber you might have seen in the Sears Christmas catalog. A petri dish provides a clear observation port.

We’ve covered cloud chamber builds before, ranging from the simple to ones that use thermoelectric coolers.

An Actively Cooled Cloud Chamber

September 24, 2012 by 11 Comments

This cloud chamber is designed to keep the environment friendly for observing ionizing radiation. The group over at the LVL1 Hackerspace put it together and posted everything you need to know to try it out for yourself.

A cloud chamber uses a layer of alcohol vapor as a visual indicator of ionizing particles. As the name suggests, this vapor looks much like a cloud and the particles rip though it like tiny bullets. You can’t see the particles, but the turbulence they cause in the vapor is quite visible. Check out the .GIF example linked at the very bottom of their writeup.

The chamber itself uses a Peltier cooler and a CPU heat sink. The mounting and insulation system is brilliant and we think it’s the most reliable way we’ve seen of putting one of these together. Just remember that you need a radioactive source inside the chamber or you’ll be waiting a long time to see any particles. They’re using a test source here, but we saw a cloud chamber at our own local Hackerspace that used thoriated tungsten welding rods which are slightly radioactive.

[Thanks JAC_101]

Researching Cosmic Rays With Cloud Chambers

September 7, 2012 by 2 Comments

In the late 1940s, the US Naval Research Laboratory used a few German-built V2 rockets to study cosmic rays from above Earth’s atmosphere. To do this, a nitrogen-powered cloud chamber was fitted inside the nose cone of these former missiles, sent aloft, and photographed every 25 seconds during flight. When [Markus] read about these experiments, he thought it would be an excellent way to study cosmic rays from a high altitude balloon and set about building his own Wilson cloud chamber.

Cloud chambers work by supersaturating the atmosphere with water or alcohol vapor. This creates a smoky cloud inside the chamber, allowing for the visualization of radiation inside the cloud. Usually the clouds in these chambers are made in a very cold environment using dry ice, but rapidly decreasing the air pressure in the chamber will work just as well, as [Markus] discovered.

[Markus]’s small cloud chamber uses a CO2 cartridge to provide the pressure in the cloud chamber before dumping the CO2 out of the chamber with the help of a solenoid valve.

In the video after the break, [Markus] demonstrates his cloud chamber by illuminating the cloud with a laser pointer and introducing a few alpha particles with a sample of Americium 241. It looks very cool, and seems to be useful enough to count cosmic rays aboard a balloon or amateur rocket.

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Your Very Own Cloud Chamber

January 23, 2011 by 28 Comments

 

[Kenneth] and [Jeff] spent a weekend building a cloud chamber. This is a detection device for radiation particles that are constantly bombarding the earth. It works by creating an environment of supersaturated alcohol vapor which condenses when struck by a particle travelling through the container, leaving a wispy trail behind. This was done on the cheap, using isopropyl alcohol and dry ice. They already had a beaker, and after a few tries figured out that the dry ice worked best when serving as a bed for the flask. A black piece of paper was added inside the base of the container to help raise the contrast when looking for condensate. They experimented with a couple of different methods for warming the alcohol, including an immersion heater built from power resistors.

There’s a video explaining the apparatus which we’ve embedded after the break. It’s a bit hard to see evidence of particle travel in the video but that’s all the more reason you should give this a try yourself.

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Peltier Cooler Based Cloud Chamber

May 7, 2010 by 22 Comments

[youtube=http://www.youtube.com/watch?v=eKfx4Rjf0BU&feature=player_embedded]

[Rich] shares with us his build of a Peltier cooler based cloud chamber. This nifty little tool allows him to see the paths that radioactive particles take through alcohol vapor. The system he has come up with is fairly cheap at roughly $100. He’s using Peltier coolers from computers and a cheap ATX power supply. You can see a more detailed instructable here.

[via Make]

Cosmic Ray Detection At Starbucks?

March 26, 2024 by 23 Comments

Want to see cosmic rays? You might need a lot of expensive exotic gear. Nah. [The ActionLab] shows how a cup of coffee or cocoa can show you cosmic rays — or something — with just the right lighting angle. Little bubbles on the surface of the hot liquid tend to vanish in a way that looks as though something external and fast is spreading across the surface.

To test the idea that this is from some external source, he takes a smoke detector with a radioactive sensor and places it near the coffee. That didn’t seem to have any effect. However, a Whimhurst machine in the neighborhood does create a big change in the liquid. If you don’t have a Whimhurst machine, you can rub a balloon on your neighbor’s cat.

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