Building a Geiger counter and testing different free available radioactive materials

#DIY #geigercounter #radioactive
DIY α, β, and γ sensitive Geiger counter I designed and built. The highest activity was shown by an old gas mantle containing thorium dioxide, which at that time was a commonly major component of the incandescent mantle, as it is also called. All the radioactive materials can be bought with no restrictions on eBay.
I also show how to convert cpm to µSvh.

[@Marbslab]

Files are available on GitHub now: github.com/Marbslab/Open-source-Geiger-counter

[@BGN-pb3fx]

very good sir keep it up

[@Marbslab]

Thank you, I'll do my very best.

[@PencilsMan]

Best video I’ve seen from a small channel in a while (no hate to others this vid is good in my opinion also new sub)

[@Marbslab]

Thank you very much.

[@matiastaranto2942]

Very nice work, the circuit simplicity really surprised me!

[@Marbslab]

Thank you :)

[@Emiliobargle]

That was really cool, and surprisingly simple! Are you planning on making the pcb schematic, BOM, and code available anywhere? I wouldn't mind building one of my own if so.

[@Marbslab]

Thank you. It is planned to publish it as open source if there is interest. This also includes the gerber files. You only need to send them to your PCB fab and you will get the PCBs. I will post a link when it is done, but it may take some time.

[@Emiliobargle]

@@Marbslab Awesome, thank you for doing that!

[@Marbslab]

@@Emiliobargle Done, see pinned comment/link :)

[@firewalldaprotogen]

how does it perform on very high activity samples? (something in the count rates of a couple thousand)

[@Marbslab]

Answered already two times, but TH-cam doesn't show the answers... See for example: nvlpubs.nist.gov/nistpubs/jres/42/jresv42n3p241_A1b.pdf

[@dg0mg]

A lot of effort and well build. Unfortunately, the circuit 0:23 min has one major drawback: The high voltage generation is UNREGULATED. There is no stabilization of the 500 volts and no feedback to the pulse generator for a closed control loop. The input voltage (5V) is stabilized, but the high voltage probably collapses under higher loads (high pulse rate). You can test this by short-circuiting the counter tube. Then around 45µA will flow through R6+R7, but 500 V should still be present at C4. I don't think that will be the case.

[@Marbslab]

You are right, the unregulated HV is a drawback of that simple design. It's no problem for the operation range of the tube (450 - 650V), but the voltage may collapse at a very high pulse rate.