CHM14 Neutron Detector

[Mark Rowley]

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

[Richard Hull]

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