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Re: Gamma Spectacular Neutron Counting

Posted: Tue Dec 12, 2017 6:33 am
by Silviu Tamasdan
The only way to set your discrimination threshold correctly is to use a neutron source and at least one gamma source. Otherwise it's mostly guesswork.

Re: Gamma Spectacular Neutron Counting

Posted: Mon Dec 18, 2017 10:13 am
by Tom McCarthy
Steven, thanks for the advice on the advanced filter, I wasn't aware of that. It's very useful. The cables I'm using are the same ones you sent me. The SHV RG-58 pre-amp to GS-PRO is 1m, the cable from the Reuter Stokes 3He tube to pre-amp is 0.85m and the 3.5mm audio cable pre-amp to laptop is 0.5m. I generally don't stretch them taut to full length, instead having one or two coils. Could this be an issue?

I've not got a chance to test with a neutron source yet. I can't make one myself as I've misplaced my Beryllium that I was going to match with the Americium source in school.

However we do have a 5 uCi Cobalt-60 source. I used it to check out the tube's response to gamma. Volume was turned down a bit as per Steven's recommendation and it's not a long run (2 minutes) so there may not be any neutrons in the data. It does give a rough threshold for where gammas end though. Data is attached.

As already advised, I can't be convinced of where neutrons start until I get access to a neutron source.

Tom
Pulse height histogram of 2 minute Co-60 source
Pulse height histogram of 2 minute Co-60 source
gamma2mins.zip
Co-60 2 minute run data
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