This project was an experiment to see if a multilayered array of Geiger–Müller Tubes (GMT) could track ionizing particles as they pass through. The result is an interesting display demonstrating how cosmic rays travel down through the atmosphere at different angles.
In the video random flashes are the result of terrestrial background radiation in and around the 18 GMTs but when you see a line of 3 or more simultaneous flashes these are the result of a muon (cosmic ray) passing though. The red LED flashes when more than three blue LED flashes and the level control sets the sensitivity.
Circuit design for the 9 Channel Geiger–Müller Tube Detector to 5V TTL this detector uses two of these giving a total of 18 outputs.
Note: The IC used in this desing a 74HC14 and not 74LS14. The 74HC14 is a high-speed Si-gate CMOS device Low-power Schottky TTL. It provides six inverting buffers with Schmitt-trigger action. It transforms slowly changing input signals into sharply defined, jitter-free output signals.
The above circuit is design to discriminate between terrestrial background radiation and strikes that are the result of a muon passing through. This is achieved by adding a resistor in series with the LED array and measuring the voltage drop across it. The greater the number of LEDs are lit simultaneously the higher the voltage across it. A darlington transistor amplifier increases the voltage to set a level using a schmitt trigger which drives an LED indicating a muon was detected.
Final PCB design of the 9 Channel Geiger–Müller Tube Detector to 5V TTL
Geiger-Müller Tube (GMT) CI-1G
I'm also using Russian Geiger-Müller tubes in this experiment which are described as being Gamma sensitive and available on ebay at very low cost less than the common SBM-20 Tubes that I have use before.
Gamma Sensitive: unknown rate
Working Voltage: 360 - 440V
Plateau: Length/ Inclination: 80V/0,125%/V
Own Background: 0,4 Pulses/s
Load Resistance: 5 - 10 MOhms
Working Temperature Range: -400 +500 С