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.
Step 1: Stuff 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!
- See the bottom of this page for info on a single-Peltier option
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