Pretty cool. I will try to build one myself. I wonder if a high voltage and a smaller chamber may work ? Well just like a Geiger Tube, except you build one as a ion chamber, higher voltage ( 50 – 300 ) and small ( medicine bottle with alumunium as cathode ) I really like these homemade projects. I call them “McGiver” projects. I just read Electronics Now – January 1994, an article about build a radon dectector. It use a pop can as a chamber , high voltage and a JFET to receive the signal. Intersting.
Where can I buy 1/4 mil aluminized mylar for the window?
I bought a roll from e-bay. The seller was selling it for basement type grow rooms, but it is aluminized Mylar that is extremely thin.
Hi. I want to know that the DMM is measure in voltage or current. Besides, how can i relate the ionizing radiation with the data i get from the DMM. Thanks. Your help is really appreciated. Wait for your reply !!! Thanks again
Ion-chamber differential sensing (comment).
These are my immediate observations regarding this schematic / circuit topology.
As shown, the amplifier electronic schematic is fully differential, i.e. diff_in and diff_out, this is OK.
In my opinion it would be advantageous to connect the ionization chamber terminals (can-center wire and can-wall) to the +/- differential inputs. This will double the input-current gain. This may eliminate the need for input-offset adjustment for well matched darlington pairs (eliminate the potentiometer).
However it will require adding a common-mode input-bias voltage circuit, made of high-value resistive divider.