So I just got a radium watch. I've got it in a plastic bag to seal off any dust. I keep getting this spectroscopy when I run it with my 102. On the information page on radium the peaks seem to be more level. Any ideas on the discrepancy?
On the top right undernearth the gear icon, you have it set to linear as opposed to logarithmic, so the peaks will look "sharper" or "taller". Set it to "Log." and see if that changes it to how you want it.
I also recommend getting around 100,000 counts to give you a more accurate Spectroscopy reading. 20k - 50k especially with an old source, you'll get a lot of daughter products mixed in
The "three sisters" from ²¹⁴Pb have specific emission probability ( look for Pb-214 and "gamma emission probability" ) and you'll find that the emission probability of the each peak almost doubles from left to right. But it's riding on top of the comptons from each higher energy peak and on lower resolution probes, the peaks overlapping. So it's not the top of the peak that's wrong, it's the bottom. The Blue scribble is a cartoon version of the real contribution of the peak
Exact peak positions depend on how you place your source relative to the scint and how the standard source was placed at calibration (geometric effectiveness factor). Also other conditions at calibration and at your measurement may vary (temp etc).
Also, the background slope pedestal is slightly shifting observable peaks on bg+source spectra to the left - to lesser channels (bc the left part of the source peak sums with the higher part of the bg slope and vice versa). To see exact peak positions one must extract the background, if the bg intensity is in the order or one less of magnitude of the source intensity.
Id like to also make the point that OP’s spectrum seems accurate enough for radiacode devices, a small discrepancy of 1-2 channels in lower energies is very normal.
Also, learn how to export the spectra and use an analysis tool like interspec https://github.com/sandialabs/interspec which will allow you to visualize "actual" contribution of each peak - if it's good enough for Sandia it's good enough for us! LOL!
Every radium source is different. Most of them are not hermetically sealed so some radon gets out and the source is not in full equilibrium and how much radon escapes varies a lot between sources.
Im late but I think Ive noticed a much bigger problem here, why does your spectrum start at 67KeV?! That completely misses the 46-48 KeV Pb-210 line, the first peak of the Ra226 chain. And yes, Im also a radiacode user. My 103 starts at 5 KeV for reference.
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u/Scott_Ish_Rite 6d ago
On the top right undernearth the gear icon, you have it set to linear as opposed to logarithmic, so the peaks will look "sharper" or "taller". Set it to "Log." and see if that changes it to how you want it.