Autunite (Uranium Ore) Spectrum

[Go-Figure]

Hello there,
A couple of days ago I received my first uranium ore, a sample of Autunite. Actually, five samples.
So far I detected Uranium in many spectra, but always mixed up with other things. This object was supposed to give me my first “clean” Uranium spectrum.
I put the samples inside hermetic small plastic bags always using gloves while touching them (no direct contact). A rock can easily crumble and produce dust, and we all know the real danger with alpha emitters is inhaling or ingesting them.

I guess some small amount of Radon will accumulate inside the bags so I will pay attention to that if I open them.

The samples are not terribly hot, I saw some Uranium ore getting as high as 50K or 60K CPM. These ones go no higher than 4000. Maybe a bit more, I wanted to get them inside the plastic bags as soon as possible so maybe I didn’t test them as extensively as I should had while they were still out. But I will do it no doubts.
Right now I am getting less than that from my Geiger counter because the plastic, however thin, is enough to block a fair share of alphas.

This is a 6 hours spectrum, with background subtraction, taken last night. All expected peaks are there and clearly visible, with the only exception of the one at 46 keV. There I have a gaussian correlation but the peak itself is not so obvious to see in the spectrum. Being pretty weak I wasn’t sure whether to call it or not, but since it sits right at 46-47 keV I concluded it’s probably due to Pb210. Incidentally that’s the first time I identify Pb210 in my spectra. I mean, it’s the first time it"s clear enough for me to do that.

I will test the other four samples in order to see if any significant difference shows up.Have a nice Saturday!

Massimo

[pilgrim]

Good work, Massimo!
A took a spectra of a Pitchblende sample few days ago, in my lead shield but It wasn't good as yours.
I have to try the PRA's background subtraction, it seems to work very well!

[Go-Figure]

Good work, Massimo!
A took a spectra of a Pitchblende sample few days ago, in my lead shield but It wasn't good as yours.
I have to try the PRA's background subtraction, it seems to work very well!

Thank you Daniel,
Yeah, actually works just fine!
The downside is that before every measure you have to take a 4-6 hours background but I don't mind too much, I like to monitor backgrounds.

Yesterday I tested the second sample (below). The Pb210 peak didn't show up. There was some gaussian correlation but it was so weak it was hard to take it seriously.
The Bismuth 214 peak at 1120 keV looks a bit lower than it was in the previous one.
A part from that it's pretty much the same, unsurprisingly.

Massimo