Gamma Spectrometry Forum

Good question. In the USGS gamma / xray photopeak manual, it has an entry at 17 keV for Pb-210 - so I stupidly believed the US government. But nobody else seemed to have that, and on looking at R. L. Heath's compendium, Pb-210 has a low probability alpha decay route to Hg-206, which produces a lot ...

A note for those of you new to using CapeMCA software on Windows with a CapeSym USB MCA: The "obvious" software download link on the CapeScint webpage is NOT (at least currently) the latest version of the MCA software, AND the latest version may not be what you need (depending on your har...

Bob, That's an interesting technique that I have not heard of before; thanks for sharing. The references I've seen for Pb-210 show the 47keV peak, but nothing (specific) at 15 keV. I did find some references showing Bi x-rays in that region, so I assume that's what is causing that peak. Is that your...

Anticlimactic conclusion to the saga: severe calibration error. It kind of occurred to me that I should not be seeing the K-40 peak at all on the shielded background spectra, as 4" of lead should attenuate that 50:1. In comparing the counts in the same interval between shielded and unshielded ...

In addition to my attempts to figure it out myself, I also contacted the person who runs allradiactive.com because they had an article ( https://allradioactive.com/why-are-vintage-lenses-radioactive/ ) about radioactive lenses that included a gamma spectrum. Because the spectrum they posted is cut o...

Bob, What a fun mystery. I spent a little time over the last week trying to figure out what it could be and I couldn't come up with a solid explanation. I have two theories that I'll share for what they are worth, and some additional information I gathered. As a hobbyist, take my input for what it's...

The cost was $1540 (USD) plus tax and shipping, so there certainly are other cost-competitive options. I finally decided I wasn't going to get around to putting together a different solution and I liked the small size and physical simplicity. They do have an older version for sale on eBay (last I lo...

Update: CapeScint does sell the separate USB MCA and they even have them in stock. I'm not sure why, but after our initial conversation there was a multi-week delay getting some questions answered and getting it on order (I'm guessing they only have once person who handles sales). Once they got back...

Stelios, If you are trying to figure out a new detector, new MCA, and new software all at the same time you should brace yourself for a challenge. I have been there and made it through, but it can be frustrating at first. Are you using a shield for your measurements? That will make a big difference ...

Thanks Rob! I have been following this thread for a while and read through it again today; you've posted an amazing amount of information. I haven't had much time to focus on gamma spectroscopy recently and I just wanted to make sure nothing had changed for the worse with CapeScint before I spent mo...