December 15th, Rich Olson presented his two projects, Peltier Cooler Based Cloud Chamber and Arduino Powered Laser Show. Learn more at his website. He is a passionate advocate of documentation. Explaining your projects helps others make and improve the projects and then link back to you, contributing to a thriving maker culture. His projects can also be found at Instructables Member: nothinglabs. and nothinglabs (Rich Olson / nothinglabs.com) · GitHub. (Great step-by-step instructions with excellent pictures!)
First, Rich Olson showed us how his laser show worked with galvos (galvanometers, it uses audio speakers to aim the laser), Arduino , and python (to scan Twitter for hashtags or any other string of your choice. He uses a laser pointer for the laser, so don’t think you’re building a crazy laser! The laser he recommends is eye-safe, (a great project to do with the kids!) The laser resolution depends on the accuracy of your galvos which control the X and Y axis using mirrors. The coordinate system is 256 x 256 – but the real resolution is lower (maybe half) that.
The cloud chamber demonstration was incredible. Science visualized. (Watch the video on Youtube!) So, we can’t really see radioactivity, but we can see see paths left by ionizing radioactive particles. Rich described the difference between alpha and beta decay, and how it affects super-cooled alcohol vapor-precipitate. We saw streaks from Americium 241 (from a smoke detector), Potassium 40 (Welcome to Nu-Salt®) and Thorite (which is so radioactive, he has to keep his big samples sealed in a box in his shed!). Lead 210 decays into Polonium (see: decay chain). Rich recommends for those radioactive sample buyers out there, “Buy it for the lead and get the Polonium for free.”
He addressed some mod issues to the project. What if we add a magnet? Magnets have mass and it disports the path of the alcohol, but try an external coil. Why not use a metal platform and get a bigger space for the chamber? Plastic doesn’t conduct heat well and that’s why it’s recommended. It’s much easier (less voltage) to cool a small platform of plastic than a larger one of metal. All the cooling is focused like a funnel to the smaller area.
Extra links regarding Radioactive and Cloud Chambers:
Peltier Cloud Chamber exposed to x-rays (extended version) – YouTube.
Check out bionerd23 – YouTube. She goes to Chernobyl to measure the radiation! Yikes!
http://chambrebrouillard.wifeo.com – great info on various particle traces
http://wilsoncloud.wordpress.com– very impressive chamber builds