Problem with my cloud chamber -- have a mist but no tracks

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Discussion Overview

The discussion revolves around troubleshooting a Peltier-based cloud chamber that produces mist but fails to show particle tracks. Participants explore various factors affecting the operation of the chamber, including temperature, humidity, and alcohol concentration.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant notes that the cloud chamber should operate at 100% relative humidity with isopropanol vapor, rather than in a foggy condition, as the vapor must condense around particles to form visible tracks.
  • Another suggests reducing the temperature difference between the vapor source and the cold plate, proposing that less power to the Peltiers might help.
  • A participant lists several factors to consider, including using a higher concentration of isopropanol, ensuring a proper temperature gradient, and employing low-angle bright lighting to enhance visibility of tracks.
  • One participant shares their experience of successfully increasing the amount of isopropanol used, suggesting that pouring more (3-6ml) improved their results.
  • Another participant expresses frustration, stating they have not been able to make their cloud chamber work at all, mirroring the original poster's issues.

Areas of Agreement / Disagreement

Participants express various suggestions and experiences, but there is no consensus on a single solution to the problem. Multiple competing views on the factors affecting the cloud chamber's performance remain unresolved.

Contextual Notes

Participants mention specific conditions and setups, such as the need for high alcohol concentration and the importance of temperature gradients, but these factors may depend on individual configurations and are not universally applicable.

Nicube
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TL;DR
Problem with my cloud chamber, have a mist but no tracks.
Hi,
For a few weeks I'm trying to build a Peltier based cloud chamber. I use a stack of 3 Peltier (from the bottom, a tec1-12710 12v, tec1-12710 5v, tec1-12709 5v and on top a 60mmx60x2.5 copper plate). I mesured -37° celsius on top of the last Peltier ans -27° on the copper plate. I also have an high tension module and use pure isopropanol.
On one of the first try I got beautiful tracks from natural radiation, but since I can't make it work again. I have a mist, but no tracks. I also tried running it outside, the plate was at -36°, I had a bigger mist but still no tracks.
Do you guys have an idea why it doesn't work ?

The only time the cloud chamber worked :
 

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Nicube said:
Summary::. ...I have a mist, but no tracks. I also tried running it outside, the plate was at -36°, I had a bigger mist but still no tracks
The cloud chamber should be operated at 100% relative “humidity” rather than in a condition where a fog is present. Humidity here meaning isopropanol vapor. The fog chambers I have used were clear - not foggy. The speeding particle induces disturbances in its wake that allow the volatile component to condense into a fog. If the vapor has already condensed though...
 
A fix would be to decrease the temperature difference between the vapor source and the cold plate. Less power to the Peltiers?
 
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There are a few factors to consider, assuming you already have the low temperature needed:

- concentration of the alcohol should be as high as possible (min 91% but higher is better)

-temperature gradient - top of the chamber where is the alcohol evaporation taking place should be higher than the bottom (you can use some sort of heater)

- evaporator surface should be evenly situated above the active area - felt works best!

- use low angle bright, sharp (not diffused) light and darken the room. The kind o light that shows off dust particles in the air

- finally consider an "Ion scrubber" - this is a high-voltage field which cleans the ions from the camber and "resets" it.

Before building an actual one...just get an inflated balooon, rub it in some wool to pickup static electricity charge and place it on top of the chamber.
you can take a look at my Cloud Chamber build - blog.kotarak.net
 
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Had the same problem, poured much more Isopropanol 3-6ml - worked as a charm.
 
Nicube said:
Summary:: Problem with my cloud chamber, have a mist but no tracks.

Hi,
For a few weeks I'm trying to build a Peltier based cloud chamber. I use a stack of 3 Peltier (from the bottom, a tec1-12710 12v, tec1-12710 5v, tec1-12709 5v and on top a 60mmx60x2.5 copper plate). I mesured -37° celsius on top of the last Peltier ans -27° on the copper plate. I also have an high tension module and use pure isopropanol.
On one of the first try I got beautiful tracks from natural radiation, but since I can't make it work again. I have a mist, but no tracks. I also tried running it outside, the plate was at -36°, I had a bigger mist but still no tracks.
Do you guys have an idea why it doesn't work ?

The only time the cloud chamber worked :

Hello, I tried making a peltier cloud chamber using the same peltier setup as you. Now I have the exact same problem as yours mine never worked at all. Did you make it work if so how?
 

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