CHM14 Neutron Detector

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.
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Mark Rowley
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Real name: Mark Rowley
Location: Sacramento California

CHM14 Neutron Detector

Post by Mark Rowley » Wed Jun 26, 2019 8:29 pm

Running some preliminary tests using a Ludlum 2221 scaler and a boron CHM14 neutron detector.

My neutron source is a 10 month old Po210 Nuclispot paired up with Be. It’s far from its original potency but it still gives me some output I can use for testing.

The moderator is a 10x8” cylinder of paraffin wax.

With no moderator or source nearby, the CHM14 will average around 1cpm. With the source and tube in the moderator cavity I average approx 15cpm. As a side note, my neutron count numbers were almost double 10 months ago when the Nuclespot was new.

The tube is blind to all the Ra226 gamma sources I have on hand. I’ll conduct the same test with xrays from the fusor later this evening.

Mark Rowley
Last edited by Mark Rowley on Thu Jun 27, 2019 4:49 am, edited 1 time in total.

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Richard Hull
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Re: CHM14 Neutron Detector

Post by Richard Hull » Thu Jun 27, 2019 4:37 am

Sounds good to me. You seem to have the bias setup right. Oddly I was working with my NIM neutron system today. I had to add two quarts of water to the moderator. (evaporation) I flipped out as it seemed to read only about 1/2 what it should until I checked the moderator and saw it was only half full. All O.K. now.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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