Have you thought about adding some kind of room-temperature spectroscopy along with your Geiger counter? Might be interesting to correlate with spikes in the count rate.
Absolutely. That's part of why I'm delaying. A professor at the University of Michigan is working on a similar project and I want to catch up with her. They're using a cheap(ish) proportional counter to be able to identify all of the isotopes that you might be looking for in a variety of wartime or accident scenarios.
