A DIY geiger counter that uses a PIN photodiode as a substitute for an expensive Geiger-Mueller tube. It detects alpha and beta radiation particles. The circuit is soldered onto a small protoboard and everything is placed in an aluminum enclosure. Copper tubing and a piece of aluminum foil is used to help filter out noise and RF interference.
Soldering iron and solder
Step drill bit
3 CR1620 coin-cell batteries, or any coin-cell batteries to add up to 9V
2 pieces of 1/2" diameter x 2"L copper tubing available at Home Depot