My cloud chamber didn't make any tracks....

In summary, Jamie attempted to make a cloud chamber using an aquarium and dry ice, but did not see any tracks. His son sang in the background. He plans to try a smaller chamber with a better setup next time.
  • #1
doggonemess
9
2
Greetings all,

I finally made a cloud chamber using an old aquarium and dry ice. Now, I got the expected result to happen, with a fine mist falling from the top like snow, but didn't see a single particle track. Any ideas why this might be? I have some guesses, but wanted someone with experience to help me troubleshoot.

My guess would be that the volume of the chamber was too large compared to the amount of dry ice used, making the chamber cold, but not cold enough. It could also be that air was entering the chamber, as I could definitely see convection in the mist.

I have a few videos, which I'll try to upload just for fun.

Thanks!
Jamie
 
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  • #2
I uploaded a low-res copy of the video here:



The plate at the bottom of the tank is Fiestaware. I figured I'd give myself the best shot I could at 'seeding' the chamber with radiation. It is absolutely the most energetic beta source I have - it makes my Geiger counter go nuts. Still nothing.

Oh, and that's my son singing in the background. At first I thought he was singing "Ode to Joy", but then I think after it might be Star Wars...
 
  • #3
Hi!
Have you any luck with your cloud chamber?
 
  • #5
Maybe there aren't very many cosmic ray particles.
I used a project from Scientific American about 56 years ago. Aluminum sheet and epoxy glue. Coolant was dry ice in methanol, about -40 degrees. You need a very, very bright light.

A speck of Americium from an old smoke detector should provide good alpha tracks.
 
  • #6
It's funny that you mention Americium, as I do have a sample of that. But I have a better sample - Fiestaware. Judging by my Civil Defense radmeter, it should be spitting out beta particles like crazy. I think the problem was my setup. I plan to do much better next time.
 
  • #7
IIRC, the 'Nuffield' cloud-chamber in our school's physics lab had 'bad hair days' when it would fog okay but not track. We never did figure why...
 
  • #8
MRBlizzard said:
A speck of Americium from an old smoke detector should provide good alpha tracks.

doggonemess said:
It's funny that you mention Americium, as I do have a sample of that.
but remember that the Americium will have to be inside the chamber
as the alpha particles won't penetrate the glass case and any paths seen
will be very short.

doggonemess said:
But I have a better sample - Fiestaware

what is that ? never heard of it

doggonemess said:
Judging by my Civil Defense radmeter, it should be spitting out beta particles like crazy

most radiation detectors respond primarily to gamma particles (rays) tho some will respond to
them, maybe your unit is of that type
 
  • #9
Geiger counters around Fiestaware (about 14% by weight uranium in the glaze of the depression era orange-red version) catch mostly beta radiation, according to the literature I've seen. I worked in a museum for 3 years with a cloud chamber. It typically took about an hour after startup to start getting good tracks. Chamber also needed periodic maintenance for best results. I think the ethanol (recycled in a museum-class cloud chamber) was picking up moisture from the air, and became ineffective when the water content got excessively high. Lab-grade high-purity ethanol is recommended. Good lighting is also a big issue.
 
  • #10
The light source I used was my father's slide projector. The light shines in from the side. Another problem was getting the right amount of water onto the black felt on the bottom of the cloud chamber. (I'm amazed I remember these problems.)
 

1. Why is my cloud chamber not producing any tracks?

There could be several reasons for this. It is possible that the chamber is not sealed properly, allowing air to enter and disrupt the formation of tracks. Another possibility is that the voltage is too low, causing particles to move too slowly to leave tracks. Additionally, the chamber may not be cold enough, as lower temperatures are necessary for condensation to occur. Lastly, if the environment is too humid, the water vapor may be hindering the formation of tracks.

2. Is it normal for a cloud chamber to not make any tracks at all?

No, it is not normal for a cloud chamber to not produce any tracks at all. If the conditions are correct, such as low humidity and proper voltage, there should be some tracks visible. If you are consistently not seeing any tracks, it may be a sign that there is an issue with the chamber itself or the setup process.

3. Can the type of particles affect the visibility of tracks in a cloud chamber?

Yes, the type of particles can definitely have an impact on the visibility of tracks. Generally, particles with a higher mass and charge will produce more visible tracks. For example, alpha particles are typically more visible than beta particles in a cloud chamber.

4. How can I improve the visibility of tracks in my cloud chamber?

There are a few ways to improve the visibility of tracks in a cloud chamber. First, make sure the chamber is properly sealed and that the voltage and temperature are at the correct levels. You can also try using a stronger source of radiation, such as a higher activity radioactive source, to increase the number of particles passing through the chamber. Another option is to use a stronger alcohol solution in the chamber, as this can sometimes improve the contrast of the tracks.

5. Are there any safety precautions I should take when using a cloud chamber?

Yes, there are some safety precautions that should be taken when using a cloud chamber. It is important to use a low activity radioactive source and to handle it carefully to avoid exposure. Additionally, the chamber should be used in a well-ventilated area to avoid inhaling any alcohol vapors. It is also recommended to wear gloves and safety goggles while setting up and handling the chamber.

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