Homemade GM tube
Posted: Tue Mar 06, 2018 8:54 am
Hi Jeff,
I hope you can give me a good advice once more.
I am using GM tubes as sensors to detect cosmic rays.
Recently I had the chance to cut up one of them and have seen their simple design.
Thus I began to make one sample by myself. Since then I made various pieces, changing each time tube material, shape and dimensions, filling gas mixtures and pressure, and of course the high voltage levels.
In no cases I was able to get them working.
A bit at a time I realized that those devices are not as simple as they appear to be. The commercial products possibly use noble and quenching gas at very strict percent and exact pressure. In my tests I used Argon and propane in various proportions and went down to 30 mm Hg. pressure, but I don’t know if they are the the right ones. Unfortunately there is no detailed literature on the web about those features, thus my tests are based on the trial and error process.
A Japanese guy says he made a Geiger sensor out of a film canister, a sheet of paper as cathode(?!) and few other things. It allegedly works on an air-propane mixture at atmospheric pressure.
On the contrary, I made my detectors much like a commercial GM tube, but nevertheless they don’t work.
Do you have a detailed knowledge on how a GM tube is made, especially with respect to the kind of gas mixture and its percent, and the level of its pressure?
Anyway, is there anybody in this group who made a GM tube and is willing to share his experience with me ?
Thank you so much.
Antonio Zanardo
I hope you can give me a good advice once more.
I am using GM tubes as sensors to detect cosmic rays.
Recently I had the chance to cut up one of them and have seen their simple design.
Thus I began to make one sample by myself. Since then I made various pieces, changing each time tube material, shape and dimensions, filling gas mixtures and pressure, and of course the high voltage levels.
In no cases I was able to get them working.
A bit at a time I realized that those devices are not as simple as they appear to be. The commercial products possibly use noble and quenching gas at very strict percent and exact pressure. In my tests I used Argon and propane in various proportions and went down to 30 mm Hg. pressure, but I don’t know if they are the the right ones. Unfortunately there is no detailed literature on the web about those features, thus my tests are based on the trial and error process.
A Japanese guy says he made a Geiger sensor out of a film canister, a sheet of paper as cathode(?!) and few other things. It allegedly works on an air-propane mixture at atmospheric pressure.
On the contrary, I made my detectors much like a commercial GM tube, but nevertheless they don’t work.
Do you have a detailed knowledge on how a GM tube is made, especially with respect to the kind of gas mixture and its percent, and the level of its pressure?
Anyway, is there anybody in this group who made a GM tube and is willing to share his experience with me ?
Thank you so much.
Antonio Zanardo