Using a standard webcam and some Americium 241 from a fire detector, Jared Bouck created a PC interface for visualizing alpha radiation.

The basic idea behind this project is using the built in CCD in a USB web camera as a medium for alpha radiation to interact with. The result is a visual presentation of pops and streaks of light as the partials interact with individual pixels of the CCD. While this has a very nice effect and makes for a fantastic “screen saver”, there are more practical and important possibilities with this project.

One of the applications I have envisioned for this project is a cheap and easy genuine random number generator. True random numbers in computing are nearly impossible, and successful solutions are very expensive systems based on radioactive decay or atmospheric measurements, for example. Using a small / relatively safe radioactive source and a high res CCD or CMOS sensor and assigning a value to each pixel and perhaps mixing in an algorithm or two with an inexpensive practical PCI card that is capable of generating genuine random numbers.

I dig the idea of this being used as a true random number generator. On this note, Jared mentions that you could use this in Linux with video_entropyd to add entropy data to the kernel’s random number generator.

Alpha Radiation Visualizer