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Monday, May 3, 2010

More cloud chamber tweaks

Latest round of design tweaks + some slow motion footage:


  1. omg, the quality of track in the beggining is the same i saw in the museum ! i can't believe it ! it's really a true joy to see this spectacle! the uranium ore seems to be alive ! it's so exciting ! the track which we look are electron, and alpha which dont go far away. But i don't know what kind of particle are the thinier track, thick as an hair ? maybe electron which don't go much in the supersaturated layer+

    how much alcohol did you pour in the bottom?
    do you know the temperature near the fiber glass ?
    at 2:04, is it some black sponge in the top of container ?
    congrats !!!

  2. didn't poor any alcohol on the bottom - it just pools there on its own after a few minutes.

    fiberglass itself is about -40f - not sure about the air above it.

    I think the "black sponge" is actually felt (that segment of the video is from a slightly different setup than the one pictured - where I had some alcohol soaked felt on the sides as opposed to the round felt pads)


  3. Hi,

    Why need two different peltier elements? If top and bottom are same - chamber not works?


  4. @anonymous - it can work with identical peltiers - just it works better if the top pelt is less powerful. the top pelt -must- be run at a lower voltage (around 5v vs 12v) for stuff to work. this has to do with excess heat generated causing a cascade (bottom pelt has to pump all heat generated by top pelt)

  5. Hmm ... I cant understand - Why?
    Diffusion chamber can overcooled?
    Or problem is power source? - in "How to build" is words "At least 8 Amps" but in Peltier datasheet for 12709 is "max 9 Amps". When connected paralel two Peltiers its may be 18 Amps ... Power source have only 8 Amps. Possibly it is problem?
    Or temperature lover -15 farenheit is to cold?

  6. @anonymous

    colder is better. the problem is using the same size pelts at same voltage will result in less cooling than a single pelt.

    pelts both pump and create heat - they are not perfectly efficient.

    so top pelt can pump X amount of heat - but also makes Y amount of heat.

    so - the bottom pelt has to pump X+Y amount of heat. so - it has to be larger than the top pelt (or at least run at a higher voltage).

    it took me a while to figure this out...

  7. Ok, my sixth sense say - You right. To more cold we need remove all heat of top element warm side move out.

    In "how to build" is "static source - styrofoam cup" - how it works?


  8. @Anonymous

    lots of cloud chambers specify a high voltage source - this seems to help clear ions from the chamber - and especially helps see alpha particles

    i've found rubbing a styrofoam cup or ballon in your hair - then placing it atop the chamber provides the same effect - and is easier / cheaper to setup (a real high voltage source may work better)

  9. Polarity of high voltage is any?
    I can placed charged beer can (metalic)? This piece usuly is charged positive (some plastic in my cheap friction experiments charge negative).
    Or one of polarity ("+" or "-") is recommended?


  10. @Anonymous

    i think either + or - is better - forget which.

    balloons and styrofoam work well though!

  11. If turn some power wire turns (5...10) around camera - magnetic field bend particle tracks?

  12. @Anonymous
    yes - magnets will bend some of the tracks.- but the effect is somewhat small. you may want to use are larger neodynium magnet