Re: [GammaSpectroscopy] Terracotta Floor Tile
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The log base is just one of the many options that Theremino offers.? I had not paid much attention to it until you brought it up.? The log scale for energy is nice for me because I tend to be more interested in the low energies.? As you know the spectral lines can get crowded down there.
So I did a 24 hour scan of the roof tile.? I agree that the Th is questionable but the Rb, Sr, and Ba are much stronger.? It turns out that Sr and Ba are commonly used in glazing:
However, this appears to be unglazed tile. I found another reference where Ba is used in roof tiles to reduce
efflorescence.
I am speculating that the company (US Tile) uses a compound containing both Ba and Sr for both their glazes and for mixing with the clay to give the unglazed tile a uniform appearance.
I don't yet know where the Rb comes from.
Charles
On Tue, Apr 14, 2020 at 8:49 PM Dude < dfemer@...> wrote:
Charles,
Interesting Am Au interference, I didn¡¯t know they had gold in there.
I missed your log space in the png as I was looking at your .mca file
after looking at Mike¡¯s and Taray¡¯s with your comment to scale it up off the
screen. I assumed it was in linear.? I was referring ?to mike¡¯s plot on the
scaling to use a log scale which would do the job much better pulling the Tl-208
2.6 and the Bi 1764 out.
You¡¯re weird, sir. Can¡¯t say I¡¯ve ever seen anyone use a log other
than a base 10, 2, or e with an odd ball exponent grid interval other than base
10 and why are you using a log interval for energy?
Dud
?
?
Note that I did not identify Au as an element.? It is
just one of the reference peaks because it shows up due to the Au in the Am241
button.
I always plot in log space.? See the Xlog and Ylog
buttons on the bottom?? The exponent for Ylog was set to 1.2 so I redid it
with an exponent of 2.
Mike, if you want more squishing in the Y scale you can go
in the INI file and change it.? Of course, you have to activate the Ylog
button as well.
?Scale options
===========================================
XlogExponent= ? ? ? ? ?1.5
YlogExponent= ? ? ? ? ?2.0
ThickLines= ? ? ? ? ? ?False
?
On Tue, Apr 14, 2020 at 11:16 AM Dude <dfemer@...> wrote:
Charles,
Looks
good. Note that the Au ¡°peak¡± is really just noise(4 counts).? Its good to
have the Am and Np tags turned on to save time when doing energy ID¡¯s.
You
don¡¯t need to scale up the graph to see small peaks just switch to the Log Y
plot. It will show all the peaks and enhances the low count peaks. Ok it¡¯s not
as pretty and doesn¡¯t have all those tall sharp peaks everyone seems to like,
but it has much more information in it and is the only way to look at
spectra ?when interpreting what you got.
Look
at the Silver dollar raw spectra plotted in linear space. The low energy
instrument noise dominates the spectra with over 4500 counts and all you can
see is the Ag peak with 227 counts. Switch to Log space and everything is
seen.? I might point out the MCA was spending most of its time counting
the low energy noise below 1 keV. The lower limit discriminator (LLD %) should
have been set to cut out this noise to improve the count real time it takes to
get a peak defined.
?
Look
at the terra cotta spectra ?in log space then you¡¯ll see the weaker high
energy peaks displayed much better.
Dud
?
?
?
Mike,
you might scale up the graphs and let the large peaks go off the top.?
Then we might be able to see the 2.6 peak better.
Dud,
here is the scan of a silver dollar that has both Ag and Cu.? I scaled it
up to allow the Am241 reference peaks to be more clearly visible.
?
On
Mon, Apr 13, 2020 at 08:16 PM, Mike L. wrote:
On
Mon, Apr 13, 2020 at 08:46 AM, <charlesdavidyoung@...> wrote:
And
here are my preliminary NaI results.
Charles,
You should extend your energy out to at least K40 or to Tl208 at 2.62 MeV (as
Dud keeps suggesting).? I discovered something kind of interesting out
there.? My spectrum is not good enough to post yet, but it shows a honking
big K40 peak.? If you look at my earlier spectrum that overlays the
mantle, there is a peak a little north of 500 KeV (I labeled it Tl208) that is
not duplicated in the mantle spectrum.? I believe it might be an
annihilation peak from all those powerful K40 photons flying around.? So,
go look for antimatter reactions in your Mexican Frog ceramic flower pot.
Mike L.
My
Spectrum out to 2.6 MeV.? My probe is not very efficient on the high
energy end, but it shows a slight peak at 2.62 and the? K40 peak at 1.46
MeV.? The exposure time with the shard was about 19 hours and just a few
minutes with the mantle.? I had to use a different PMT adapter to achieve
linearity.? I need to understand what causes HV pileup and poor linearity
with my other amplifier to try and improve the hardware.
Mike L.?
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