[NewCandle] los artifactos

[Nick Reiter]

Hello, all,

Looks like I must take some egg on the face with this
one, and extend a thank you to John at the same time. 
It was not all that easy to weed out, but indeed, both
the Ag and Y pseudo-signals are apparently just that. 
I do have a call placed with the EDAX tech people to
see if they can supply me with some literature on
this, as little is mentioned in the "owners manual".

I'll not dwell on the long version, but in essence,
even a bona fide Ag signal (from looking at 200A of Ag
deposited on Al foil) loses the "second" 3.151keV line
in the grass when the magnitude drops low enough...
down to around 3 to 4% from the EDAX semi-quant.  You
really can only differentiate the double Al from a low
level but real Ag signal, by looking at a high purity
standard (I used a 99.999 Al evaporation slug)

The reason for the odd offset "Y" peak is totally
obscure to me, and I have no idea what count doubling
artifact is involved there.  However, I rounded up a
piece of 99.9% pure Al2O3 and examined that with EDS,
and sure enough, there it was.  The pseudo-Y peak does
seem to diminish more quickly when count rate is
lowered.  The count rate lowering technique for
discrimination isn't as empirically effective for the
Ag, as it lowers Fe also

So there we are.  Apologies to all for the runaround.

I do think I will look at the surface of one of our
pop-can anode glow "torches" though:)

Best,

nr

The Holy Grail 'neath ancient Roslin waits.
The blade and chalice guarding o'er Her gates. 
Adorned in the masters' loving art, She lies;
She rests at last beneath the starry skies.