Supercritical CO2 does not help visualize ionizing alpha particles

I tried to build a cloud chamber with supercritical CO2, thinking that ionizing radiation (alpha particles) would cause localized condensation of the CO2 at the point where the fluid is coming out of the supercritical state. It didn't work, unfortunately. I tested this idea with the americium-241 source from a smoke detector. I will continue experimenting with CO2 ionization chambers, and it might be possible to visualize the particles with superheated liquid CO2.

A helpful commenter pointed out that alpha particles will not travel very far in a fluid as dense as liquid CO2, so I will try again with a beta emitter.

Category:

Science & Technology

Tags:

• supercritical cloud chamber
• ionizing radiation
• supercritical co2
• co2
• bubble chamber
• cloud chamber

[Rannyfash]

alpha emmitters in smoke detectors are not nearly as powerfull as it needs to be, it wont even penetrate the perspex, use beta radiation, plus i reckon theres not a significant amount to poison you

[Flipper118118]

Enjoy all your videos as always.

Just wondering if you had any means of radiation detection? I work in the nuclear field and always wonder what kind of alpha levels one could get directly from the source in a smoke detector (have measured thru cases but never directly).

From what I have found it looks like the source is about 1uCi, even tho the alpha energy levels are nasty to biological tissue I think your free and clear unless you decided to grind it up and eat it ;).

[kd1s]

The Americium 241 is an alpha emitter. You probably want at least a beta or gamma emitter.

[bur1t0]

I was under the impression that a cloud chamber maintains a temperature gradient, and that the particle trails are only visible in a very thin slice.

Maybe by heating one side and cooling the other you can get a temp gradient if the aluminium isn't conducting it away too fast.

My brain tells me that you should have seen some cosmic radiation by now, although maybe the small size of the chamber and homogeneous temp is limiting convection so much that you're slipping past the sweet spot unaware.

[Dibblah1900]

It is possible to see alpha particles with a normal CMOS camera sensor - Obviously, you have to remove the front glass and mono is far better than color. I was also wondering if it would be possible to make a pinhole camera for alpha (short term, obviously, since the sensor will get contaminated quickly)

[Systemrat2008]

Hi Bob. I have a Radex 1706 counter which is no good for alpha detection but I have a test source of AM241 from a smoke detector similer to what your using and I get a reading of 1.27 uS at 10mm from the detector. I imagine most of that is gamma emissions. Background here is 0.08 uS. The source should be really hot with alpha radiation I can't see it with my gear.

[electrodacus]

Not sure but Am241 emit alpha only and this are large particles that will not travel far in air just a few centimeters so in dense CO2 probably much less.

I guess a source of Beta radiation may work and you can see a trail but not sure actually have no idea :)

[KiloSierraAlpha]

Awesome as always! Thanks for making a vid. Quick Q... did you modify your acrylic walls of this new CO2 chamber? Hope this one lasts longer...