Good points and I'll definitely experiment with that when the equipment can go back into "experiment" mode. Right now everything is tied up taking measurements for my database with the current sensors before bringing the SDD on line for some specific measurements.
Also we need a few new Amptek XRF libraries to quickly search for some of the individual elements and some small groupings of elements. The single element ones can contain all the XRF peaks in the K and L shells. Such a tool would be very handy at times, especially when searching a wide and complex scan such as comes from Trinitite.
Also it seems from the literature, my 24 hour long scans are just the beginning, they need to be tripled at least it seems to correlate with what NIST is doing....can you imagine that on a Ln2 cooled sensor? By the way I want to get back in touch with the college to see if their T.E. cooled HPGe is back on line and book some time there for some scans and especially to get access to their calibration samples.
G
----- Original Message -----
From: Dude <dfemer@...>
To:
[email protected]Sent: Fri, 28 Feb 2020 20:52:35 -0500 (EST)
Subject: Re: [XRF] Zircon- Malawi vs Sri Lanka
Geo,
To look at the smaller ?lower energies reduce the kV below the 15keV
Zr peak.? In general keep the kV 2-3 times the energy of the peak you are
looking for. Use a filter that has a k-edge about 1.5 times energy of that peak
to tweak stuff.? So you need to reduce the kV below 15kV to kill the Zr and higher
energy peaks and use ?no filters which should be good for Ti, Fe, Ni and Zn. ?uA
is set to keep your count time within limits, 30K cps or lower.
If you go WAY back in the original NaI ?emails you¡¯ll see we
talked about XRF from internal radiation and decay produced.
Dud
?
?
?
Here's
the longer run time Dude, there is information in the smaller peaks, but the
overwhelming peaks are swamping some of them. Should I try less Kv or less uA?
?
In the past I never noticed stable element XRF from internal radiation, not
that I was specifically looking for it. Charles' experiment have me looking
now, at least being aware.
I'm trying to keep one eye on the deadtime too, as you suggested. This scan
attached reflects the already lowered kV and uA to try to accomplish an
improvement.
For new members:?
"XRF scan" means there is an external energy source of some kind
applied to the item being tested. This can be X-Rays, Gamma-Rays, beta
particle. electron beams, protons etc.
"Gamma Spectrum Scan" is a passive scan where only the rays naturally
coming from the sample are being detected and charted. Thanks to a Charles
Youngs experiments, we are looking for and are aware of internal sources of
energy in radioactive samples causing XRF without the use of externally applied
energy. Generally this is orders of magnitude lower than externally applied
energy to excite XRF.
Geo
