Radiobaryt Spectrum

[Svilen]

Here a radiobaryt spectrum taken with 2" CsI(Tl), 25mm lead shielding, no BKG subtraction, 14h; Activity of the sample ~12 cps above BKG:

Radiobaryt_CsI_14h_31_12_21.png

Radiobaryt_CsI_11h_31-12-2021.png

[Sesselmann]

Svilen,

Superb spectrum with really well defined peaks, thanks for posting.

I had never never heard of radiobarite, had to look it up.

http://webmineral.com/data/Radiobarite.shtml

[Sparky]

Great resolution! You have two small peaks between of the Bi & Pb x-rays around 80 keV and the U235 peak at 143.8 keV. Any ideas what they might be? I have had some luck with improved U spectrum features on the low energy end with marine fossils (Mosasaur or shark teeth) because the U and daughters appears to be right on the surface of the tooth, which helps the low energy features present better. You have one peak identified as Pb212 below 800 keV that might be Bi214 (768 keV)?

[Svilen]

Thank you Steven, I also recently discovered this mineral and decided to show the nice spectrum it gave, I'm glad you liked it too.

@Sparky: The upper one of the two tiny peaks is actually the U235 at 143 KeV, while the marked one is U235 at 163KeV, but for the lower peak I also have no idea.
I guess you talk about Bi212 not Pb212 near the 800KeV line - here Bi212 at 785KeV is marked, but you are right that it more likely is the Bi214 at 768KeV.

[Sparky]

Svilen,

Yes, I meant Bi212. Sorry.

Regarding that tiny peak around 110 keV, I often see it in my marine fossils. I think it is mostly two low probability U235 peaks combined. I recently found an unlabeled HPGE spectrum for U ore that showed multiple peaks in that area, so this question might not be easy to answer. The attached spectrum (Otodus obliquus tooth) labels the peak as Uka1 x-ray, but I know that is not correct.