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How to Make a Geiger Mueller Counter

Geiger Mueller counters are a handy way to gauge radiation levels. Basic model counters do not quantify radioactive particles as actual numbers. Instead, they translate the information into an audible sound, similar to the popping of dried corn kernels in an active microwave. This noise intensifies in the presence of large amounts of radiation. Detection is accomplished through use of a Geiger Meuller tube. Like a light bulb, the Geiger Meuller tube is a glass cylinder housing both a pair of wires and an inert gas, such as helium, neon or xenon. When a high voltage passes through the wires, the presence of ionizing radiation causes a detectable reaction in the gas and this reaction creates the popping sound. A working knowledge of electronics and circuit assembly is required for this project.

Things You'll Need

Geiger Mueller tube
Wires
Solder
Soldering iron
9-volt battery case
Switch
Transistor
Capacitor
Transformer
Four-stage voltage multiplier
0.01 capacitor
22 M resistor
Amplifier
9-volt battery
Voltmeter
Speaker
Plastic case

Instructions

- 1
  Wire the battery case, the switch, the transistor, the capacitor, the transformer and the voltage multiplier in series. To do this, solder wires from the battery case's positive lead to the switch. Solder wires from the switch output to the transistor. Solder a wire between the transistor and the capacitor. Solder a wire between the transistor and the transformer's positive input. Solder a wire between the transformer's positive output and the four-stage voltage multiplier. Connect the negative terminals to a common ground. This creates an oscillator similar to blocking oscillators, which power a camera's Xenon flash-tube.
- 2
  Filter the output through the 0.01uf capacitor and a 22 M resistor. Connect the filtered output to an amplifier. Insert a 9-Volt battery into the battery case. Flip the switch to its "On" position. Test the voltage with a voltmeter. Adjust the amplifier until the power supply measures 500 Volts. Flip the switch to its "Off" position.
- 3
  Solder the power supply's wires to the Geiger Mueller tube's power supply leads per the specific tube's specifications. Wire the Geiger Mueller tube's output to the speaker per the tube's specifications. Verify the system is properly grounded.
- 4
  Prepare a plastic box to house the system by drilling holes for the switch and speaker. Place the system into the prepared container to prevent unexpected wire tugging or other accidents.

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