Is this neutron counter dead?

For Short Term Learning Discussions ONLY. This area is for CURSORY questions and connecting with other users ONLY. ALL technical contributions need to be made in the appropriate forums and NOT HERE. All posts are temporary and will be deleted within weeks or months. You should have already search the extensive FAQs in each of the forums before posting here as your question may already be answered.
User avatar
Michael Kaufmann
Posts: 18
Joined: Sat Nov 13, 2021 2:05 pm
Real name: Michael Kaufmann
Location: Siberia

Re: Is this neutron counter dead?

Post by Michael Kaufmann »

guys - I found an article that describes 3 different ways to determine the helium pressure inside the counter!

I have the pdf of the original in Russian, but I also found an English version, however, I do not have access to the text to compare it with the original.
the English version is here - https://doi.org/10.1134/S0020441220010236
original - https://sciencejournals.ru/view-article ... silev#text
https://sciencejournals.ru/cgi/getPDF.p ... asilev.pdf

p.s.
since i really love x-rays, i decided to image this counter at 50 and 100 kev - will post the pictures here : )
User avatar
Dennis P Brown
Posts: 3159
Joined: Sun May 20, 2012 10:46 am
Real name: Dennis Brown

Re: Is this neutron counter dead?

Post by Dennis P Brown »

Thanks for the post on the detector parameters.

Just remember, X-rays don't love you! Proper shielding and detectors to determine exposure is critical for one's long term health - safety matters.
User avatar
Michael Kaufmann
Posts: 18
Joined: Sat Nov 13, 2021 2:05 pm
Real name: Michael Kaufmann
Location: Siberia

Re: Is this neutron counter dead?

Post by Michael Kaufmann »

heh - nothing really fancy there:

1P1010005.JPG
1P1010006.JPG

and i don't see anode wire - probably coz it's just too tiny. or coz the focus of the x-ray tube is too large.
User avatar
Michael Kaufmann
Posts: 18
Joined: Sat Nov 13, 2021 2:05 pm
Real name: Michael Kaufmann
Location: Siberia

Re: Is this neutron counter dead?

Post by Michael Kaufmann »

it's there : )

121P1010029.JPG
Matt_Gibson
Posts: 505
Joined: Thu Sep 23, 2021 10:36 am
Real name: Matt Gibson

Re: Is this neutron counter dead?

Post by Matt_Gibson »

Well that is some next level investigation right there…
Peter Schmelcher
Posts: 228
Joined: Sat Nov 13, 2010 1:56 am
Real name: Peter Schmelcher

Re: Is this neutron counter dead?

Post by Peter Schmelcher »

Your operating voltage seems high to me. I tested a CH19N and determined it was working by ramping the voltage up in steps and measuring the resulting pulse heights (Geiger plateau curve). Pulse height is the gain of the detection process and increases with voltage.
From my memory I believe the best signal to noise was around 1200 +-75V for proportional operation. The manufacturer recommended voltage was 1875V to 2100V for Geiger operation but honestly it was unusable at that voltage.
At higher tube operating voltages the circuit you are using becomes an avalanche oscillator.
Cheers -Peter
Post Reply

Return to “New User Chat Area”