Heck, I don’t know.. I was just thinking where I could get a very sensitive Geiger counter for a good price.
You can build your own using an arduino board and about $150 in a detector and other parts that is equal to those costing upwards to $800, that will detect Gamma, Beta, and even Alpha rays/particles.
You’d better have it calibrated and understand the way it works and if it detects alpha and gamma radiation, or it will be as useless as a left-handed screwdriver.