Gamma Spectrometry Forum

I've figured it out. I had wondered why, when I got a scintillator that had been worked on by someone else, my plateau voltages tended to be higher than the "as found". Then, when I set it where I thought it should be, sometimes there was a problem with noise. I always wondered whether tha...

What I mean by tee off. Per the procedure I learned from Ludlum, a tee connects the meter, for instance a 2241-2, both to the probe, usually a 44-2, and to the pulser, a 500-2. So the meter has a tee on the external connector, two cables attached to it. The pulser has a high-impedance input, display...

Hope you don't mind being bombarded with questions. What should I think when a scintillator, like a 44-2, seems to have a lot of noise? Like, plateau it, the "as found" voltage was on the slope, I put the voltage where I think it should be, and it counts vigorously in a low-background area...

Thanks, Michael. That fills out the picture for me. I wasn't thinking of the complete decay chain, just the part that caught my interest. At 1175 keV electrons have around 8 times the range in polyethylene.

Interesting. My check source is 3mm thick. I don't know what the internal geometry looks like. The tube's window is 1.7 mg/cm^2. I think betas explains what I saw.

Mike,

I did eventually see this. Pulse height! Yes, I think that's my explanation! I didn't really think of that, maybe because I'm more of a GM tube guy, but I'm sure size matters.

I was working with foot probes with three GM tubes, and the tube efficiencies were inconsistent. There was plastic over the grids to keep sand and grime away from the tubes, and sand and grime was building up in there anyway. But I thought, 660 KeV gammas, what's a layer of tape going to do to that?...

I actually did come across a survey meter with semiconductor detectors: the Fluke RaySafe 452, $4290. https://www.flukebiomedical.com/resource/radiation-survey-meters-hospitals-technology-challenges-new-approach It says "The RaySafe 452 takes a different approach and seamlessly combines several...

Thanks, Sesselman. I've seen semiconductor detectors in stationary science applications, like inside cryostats on beamlines. So totally different kind of application. It just tickled my fancy, and I thought I could see potentially an actual advantage over a gas ion chamber. But if they're not around...

I was just reading about deadtime (here, in case anyone is interested https://scholarsmine.mst.edu/cgi/viewcontent.cgi?article=3150&context=doctoral_dissertations) and, when reading about semiconductors, suddenly wondered if there are survey meters, the kind typically used for radiation safety p...