Gamma Spectacular Neutron Counting

This area is for discussions involving any fusion related radiation metrology issues. Neutrons are the key signature of fusion, but other radiations are of interest to the amateur fusioneer as well.
Silviu Tamasdan
Posts: 147
Joined: Wed Jun 28, 2006 11:17 pm
Real name: Silviu Tamasdan
Location: Connecticut

Re: Gamma Spectacular Neutron Counting

Post by Silviu Tamasdan » Tue Dec 12, 2017 11:33 am

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.
There _is_ madness to my method.

Tom McCarthy
Posts: 398
Joined: Wed May 08, 2013 7:36 pm
Real name: Tom McCarthy
Location: Ireland

Re: Gamma Spectacular Neutron Counting

Post by Tom McCarthy » Mon Dec 18, 2017 3:13 pm

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.

Pulse height histogram of 2 minute Co-60 source
Co-60 2 minute run data
(52.25 KiB) Downloaded 10 times

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