Cloud chambers let you see vapor trails left by radioactive particles!
A version of this cloud chamber is now available for purchase (fully assembled and tested) from http://www.nothinglabs.com
Discuss cloud chamber assembly and radioactive samples at http://forum.nothinglabs.com
Cloud chambers work by creating a supersaturation of alcohol vapor. Vapor trails are then formed when the radiation ionizes the alcohol.
Cloud chambers need to be very cold (about -15f) - so most designs require dry ice.
This design uses inexpensive electrical "Peltier" coolers instead! No need to buy / store dry ice!
It's fairly easy to construct - and should only cost about $100.
This chamber design cools down very quickly - you can see vapor trails within a few minutes.
On the downside - it's not as cold as a dry ice chamber - so the supersaturated area isn't as thick.
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Signing UpStep 1Stuff You'll Need (Part 1)
- Model 12709 (138 watts "max") for "top" cooler ($8 on ebay)
- Model 12710 (168 watts "max") for "bottom" cooler (also $8 on ebay)
- Search eBay -descriptions- to find specific models
- Often listed as "TEC", "Thermoelectric" or "Peltier" coolers and have TEC1 or CP1 as a prefix to the model number
- Other models with similar wattage ratings can likely be used (bottom cooler should have a slightly higher wattage rating than the bottom)
- Coolers look identical - put a piece of tape on a wire of the 12710 so you can identify it later
- Larger coolers are not necessarily better
- Fragile wires tend to break - avoid bending (might want to buy a spare or two)
- Do -NOT- connect a peltier to power backwards or without a heatsink!
Power Supply #1
- 12v and at least 8 amps (good results between about 11v and 15v)
- Used to power 'bottom' peltier cooler
- www.allelectronics.com part # PS-1512 is a good option for $25
Power Supply #2
- 5 volts and at least 2.5 amps (good results between about 4v and 8v)
- Used to power 'top' peltier cooler
- D-Link JTA0302C power supply on ebay for about $10
- Alternative: Use a PC ATX power supply for both 12v and 5v sources (Google for more info)
CPU Cooler / Fan
- Look for "heat pipes" and a 120mm fan
- Design that can be run "upside down" with good airflow
- The Cooler Master Hyper 212 works well and is cheap (under $30 on ebay)
- Cooler Master V8 works well and looks cool (about $50)
- The Corsair H50 (liquid cooling) works a little better - but is more expensive / complicated (about $70)
- See http://www.frostytech.com/ for other possible coolers
Alternative Single Peltier / Single Power Supply Configuration
- This project can also be built using a single dual-stage peltier cooler
- The 19012-5L31-06CQQ from Custom Thermoelectric ($53) has been tested and works well (order with Moisture Sealing option)
- Requires a 12V power supply capable of 6 amps (5V power supply is not needed)
- Other project details stay the same
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you will need to cut the end of the cable off the power supply's cable / solder it up to both the fan's power inputs and the peltier's. both the heatsink's fan and the peltier take 12v.
I can't tell you off the top of my head if the wires on the power supply are color-coded for polarity. You might want to use a multimeter to verify which is positive and which is negative.
I think the "box" your talking about is a big 12v power supply (the "cord" pictured is a 5v power supply). With the setup you'll be using - you'll just need the smaller 12v power supply I mentioned in the prior post.
hope this helps!
-Rich
http://www.amazon.com/Kinamax-AD-LCD12-Monitors-Adapter-Supply/dp/B000VE7GQQ/
just look for anything 12v / 6amp.
If you want to add a power switch - one of these will plug right into the power supply:
http://www.amazon.com/Power-Switch-Slim-Easy-Your/dp/B0053EONOM/
(you can find these cheaper on ebay - but they ship from china / take a long time to show up - also be aware there's s similar / but different power switch - avoid it - as it's junky)
happy to share some more info on the commercial chamber (there have been two versions - but both work about the same). glad to offer some general guidance - getting too specific probably won't be that helpfull - there is a large amount of "nuance" in how things go together.
thanks for the offer on the blueprint - would be curious to see what you come up with (I probably wouldn't include it with the manual though)
first - it uses a special (little more expensive) dual- stage peltier - this eliminates the 5v power supply (and lets you use a cheaper 6amp for the 12v) - and simplifies wiring.
for a link - look at the 2nd page of the instructable under "Alternative Single Peltier / Single Power Supply Configuration"
the cooler is a Cooler Master V8. it was chosen mostly for looks - but does work well.
the "base plate" of the current commercial chamber is made of delrin (aka acytel) - which is held in place using some fairly complex mounts I engineered.
the earlier version of the chamber uses a "garolite" fiberglass base (i don't remember if it's g-9 or g-10 - its whichever comes in black). this version was held in place using arctic silver thermal epoxy (it also had some supports for strength).
(delrin doesn't epoxy well)
I would not epoxy anything in place until you've tested the chamber using regular thermal paste.
both materials are black and 1/16th thick and available from mcmaster.com
the chamber's glass is a high quality food storage container (have only found these locally - but I'm sure theres something simlar near you). the top of the chamber has a furniture glide silicon-sealed to it to absorb the alcohol.
For more hints on how the commercial chamber works - go to nothinglabs.com - then the page for the commercial chamber - and download the manual.
hope this helps! feel free to ask any other questions.
-Rich
Are the cooling heatpipes efficient even though they are mounted upside-down ?
I mean, there's still the capillarity effect, but the gravity is in the wrong way.
I'm planning to build a cloud chamber but I'm not yet sure if I use your type of cooler or if I need to bend the heat pipe (a single sided headpipe version) in order to make them horizontal.
Thanks for the great tutorial !
Samuel from France
not sure if performance would be better with things "rightside up"
I also have a more power Corsair liquid-cooling system - which should run fine upside down - which only gets a few degrees colder than the heatpipes do (also indicating the heatpipes are working pretty well).
I highly recommend using the Kingwin HTC XT-1264 for this project. I've tested a lot of coolers - and it seems to provide the best bang for the buck.
The Cooler Master V8 is a little better - but more like $60.
Good luck - feel free to ask questions.
-Rich
I'll use the Cooler Master hyper 212+ since the kingwin is not easily available in France.
My conctruction (almost done, only need the 4 peltier) is inspired by this cloud chamber :
http://wilsoncloud.wordpress.com/2010/05/14/222/
I'll make a little overview when it's working.
Samuel
I've been in contact with the guy who made that chamber - he's done some very nice work! (seems very committed to doing research)
here's my latest video - featuring a Lead 210 alpha source:
http://www.youtube.com/watch?v=fl9OeGt5obA
good luck!
Your actual setup is very neat and gives excellent results ! I almost completed my chamber :
http://samuel.fonteneau.free.fr/cloud%20chamber/image%2013.JPG http://samuel.fonteneau.free.fr/cloud%20chamber/image%2014.JPG
Let's hope it's succesfull !
Edit : It works !!!
Here's a little video of the first experiment :
http://vimeo.com/16731396
still need a little bit of tweaking (the artic ceramic is not well applyed on one element) but it's very promising !
Thanks again for your great tutorial
Samuel
>Here's a little video of the first experiment :
http://vimeo.com/16731396
I spent last day trying to tweak the machine in order to visualize alpha rays.
In the end, I discovered that the americium button was on the wrong side :D !
It don't even seems to need a HV or electrostatic source.
it seems sometimes I can get good alpha results without static - but other times not.
I suspect how cold the chamber gets and humidity (effecting background static charge) play a roll...
also seems less intense alpha sources do better without static. I think too strong alpha sources can ionize the entire bottom of the chamber - so the static source is needed to clear things out.
glad you're getting good results!
The inexpensive ones don't have the heat pipe or large fan - are they important or are you just looking for something with the proper orientation?
they need to dissipate well over 100 watts. at very least you'll need something of decent size.
I've had some luck with larger non-heatpipe coolers - but I've generally gotten better results with the heatpipes.
there's probably no harm in trying a cheap random one (assuming it's not too small) - but if doesn't work - I'd suspect the cooler.
-Rich
is there an alternative source or model number?
thanks - creatrope
i took a look at those - they are rated at 15.2v max @ 10amps - which comes out to 152 watts consumed - so they're about the same.
i think they are probably fine.
picking coolers has some flexibility. ie - you'd probably also be fine with a 12706 on top and a 12709 on bottom
good luck!
-Rich
One thing I'm curious about is generating the vapor for the chamber. Most folk seem to do it the same way as you: soaking a sponge/cloth/etc with solvent and attaching it to the top of the chamber. I was wondering if you had ever experimented with actually warming the solvent in another container and piping it over.
My goal with this would be to make a chamber I could run more or less indefinitely...anyone ever tried this?
yes - i've spent a fair amount of time experimenting with heating the alcohol. i've never had it produce noticeably better results though. (dont let this stop you from trying though)
as for having the chamber run longer - it seems the limiting factors / possible soutions:
the static source (balloon) - can last as short as 10 minutes - but as long as 60 minutes or more depending on the balloon and how much alphas the sample is emitting. a high voltage source would address this.
after about 60 minutes - you may get too much alcohol on the chambers bottom. maybe some felt to whick it back up from the bottom - or some kind of drainage system? this problem can be reduced by not over-doing the amount of alcohol on the sponge (more is not always better)
finally - you might run out if alcohol at somepoint - but you could probably drip more from on top of the chamber via a small hole.
i haven't intentionally run the chamber as long as possible that many times - but i've had at least several times i've run it an hour or longer without tweaking anything and still got good results.
good luck!
http://www.youtube.com/user/josephraul1
Great little unit. I have made a few changes, but overall the basic unit here will work fine.
http://www.instructables.com/id/How-to-Salt-Out/
I did this today and it works as the alcohol separates to the top while the salt stays on the bottom. Only drawback is that the resulting alcohol may contain traces of salt.
if you can't find 99% isopropyl - I'd try "denatured alcohol" (which is ethyl)
joseph seems to be getting pretty solid results with 91%.
I wouldn't bother trying 70% (tried it sometime ago - didn't work well at all)
you can also try "everclear" - if they have that at your liquour store.
nice looking video!
I've also switched to a 1/32nd fiberglass (garolite brand) base plate and am using a water glass for the chamber itself.
There isn't really a seal - but it doesn't seem to matter.
You can see the setup in a video at this blog post: (also has some slow motion footage)
http://nothinglabs.blogspot.com/2010/05/more-cloud-chamber-tweaks.html
(there's also some other stuff at http://nothinglabs.blogspot.com related to the cloud chamber)
As others have mentioned - if you get things really cold the static is less fussy.
I've been able to drop my temperature a few degrees by carefully re-apply all my thermal paste using a razor blade to both sides of each surface. This has gotten me down to -40f!
The brand name of the fiberglass I'm using is "garolite" - 1/32nd inch thick.
The Garolite brand name is also used for other composite materials.
www.mcmaster.com has a bunch of "grades" - I'm using G-10. This is the same material many circuit boards are made from. Stuff is fairly cheap (under $10 for 1'x'1' sheet).
Unfortunately they don't have any of the glass-based versions in 1/32nd that are black (it's light green). So - I've had to paint mine (krylon fusion spray paint works pretty well - but can come off).
They do have 1/16th" G-10 which is black. I've used this with good results - but it seems thinner would be better.
They do have grade "XX" garolite which is 1/32nd and black. Hower "XX" isn't glass-based - it's paper-based! My research suggests it will work well - but I haven't tried it yet.
By using the razor blades I mean use them to apply a super-thin and even coat. The razor blade helps because it's super-flat / sharp / hard.
I basically apply a bit of paste to the surface - and then use the razor blade as a putty knife - getting the coating as thin as possible. Apply the past to both surfaces help further assure there aren't any gaps.
performance seems comparable to the 1/32nd glass - and better than the 1/16th glass (I've got so many variables going on - it's hard to quote meaningful numbers).
one big thing I've figured out - sometimes I test in the mornings - when the house is still 65 degrees - other times I'll test in the evening when it's 72 degrees.
as you can imagine - that's probably resulting in about a 7 degrees final temp difference.
it's quite possible things are getting colder for you - but it's not enough to visibly make a big difference.
I just got some of these lights:
http://tinyurl.com/3amo5c4
they work great!
I've moved to the Arctic Silver Ceramique - it seems to work just as well as the Arctic Silver 5 for less money.
-Rich
One other thing you can do which helps somewhat, although not as much as ice water immersion, is to place a "blue ice" pack in front of the fan (just don't allow the pack to reduce fan circulation too much or you'll burn out the fan). This also cools the chamber more, but obviously not for long term. In a pinch however, it is as effective as ice water for a short period of time.
Good luck to all who try it. As mentioned, with the project in its current form, proper charge is the key to keeping everything working smoothly.
Jon I
http://www.youtube.com/watch?v=sQcUoLQ2hd8
Joe