Radium Clock

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Go-Figure
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Radium Clock

Post by Go-Figure » 19 May 2019, 00:46

Hi folks,
The other day i put my hands on a "radium clock" and I couldn't wait to test it, which I just did.
Despite most of the alphas are blocked by the front glass the Geiger counter reads an excess of 1000 CPM (normal background = 50 CPM with the same counter) so it's pretty active.
It still exibits some weak phosphorscence, and it's clearly fluorescent under UV light, which can make for interesting photos (the one close to spectrum is pretty horribly cropped in order to make it fit).
This is an unshielded measurement so there are no peaks due to the lead shield's fluorescence.
The spectrum shows all the peaks one should expect (I think) from Ra226's and most of them are pretty sharp.
The X-Ray peak at 46 keV seems right on the money to be Pb210. The one close to it around 75-80 keV is in the right region to be Pb214, but maybe there's something else as well.
There's also a little, but visible peak around 15-20 keV which right now I can't identify.

Calibration is off by 3-5 keV accross the board for some reason and it gets a slightly worse at higher energies (far from my calibration points) but you really start to notice it only above 1500 keV.
Peaks of Bi214 are all lined up. That's the first time that I've been able to clearly detect Bi214's peak at 934.06 keV (or maybe in the past I just overlooked it). Not included in the picture there's also a peak in the region of 2200 keV which should be Bi214 again (and again, first time I "catch" it).
There's also something around 1500 keV that I am still scrapping my head on. Could it be Bi214 again at 1509 keV?

I attach both the counts per bin and the energy per bin version, since high energies peaks are much more visible in the latter.

All in all it's a very nice object, which of course I have no intention to keep on my bedside table!

Massimo
Attachments
Radium Clock - ID- 6 Hours - BG Subtraction - No Shield - 18-05-19 - Counts x Bin - 0.045 Clean.png
Radium Clock - ID - 6 Hours - BG Subtraction - No Shield - 18-05-19 - Energy x Bin - 0.045 Clean.png

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isoenzyme
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Joined: 20 Feb 2019, 17:36
Location: Utah (USA)
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Re: Radium Clock

Post by isoenzyme » 19 May 2019, 03:42

Beautiful spectra! Thanks for providing the spectra in both counts and energy per bin.
Christopher Lloyd
Salt Lake City, Utah (US)


Setup: Modified GS-STANDUP-20 with GS-USB-PRO
Primary Detector: GS 2" x 2" CsI(Tl)

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Go-Figure
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Re: Radium Clock

Post by Go-Figure » 19 May 2019, 19:22

isoenzyme wrote:
19 May 2019, 03:42
Beautiful spectra! Thanks for providing the spectra in both counts and energy per bin.
Yes. the Radium Clock didn't disappoint.
I hope I can post some more data about it shortly.

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Steven Sesselmann
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Re: Radium Clock

Post by Steven Sesselmann » 20 May 2019, 07:55

Massimo,

Pleased to see you have identified the little Pb210 peak, it was discussed in another post recently.

Steven
Steven Sesselmann | Sydney | Australia | gammaspectacular.com | groundpotential.org | beejewel.com.au |

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Go-Figure
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Re: Radium Clock

Post by Go-Figure » 21 May 2019, 07:31

Steven Sesselmann wrote:
20 May 2019, 07:55
Massimo,

Pleased to see you have identified the little Pb210 peak, it was discussed in another post recently.

Stevenhttps://www.gammaspectacular.com/phpBB3/viewtopic.php?f=5&t=506
That was the first time it showed as a genuine peak in my spectra.
I already detected it, but much less clearly, in my first Autunite's spectrum, but it didn't materialise in the spectrum of the second sample. I have three more to test and I am curious to see what will happen. I will post results here.
First two spectra are here https://www.gammaspectacular.com/phpBB3 ... ?f=5&t=506

Massimo

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