Welcome to the XRF Wiki. This Wiki is a repository of information contributed by members of [email protected]. Members can view and edit the pages. The pages are currently not viewable by the public. The pages below represent a rough overview of the technology and techniques associated with X-Ray Florescence Spectroscopy as well as serving as a place for members to organize the spectra that they have contributed to the forum.?
As a starting point, the pages will be populated by information taken from member posts from the past few years - with references/attribution. Perhaps in time, these pages can be edited by members to make them more complete and less choppy. Members can also edit this page, making the structure of the content more organized.?
Pages can contain information about a particular topic, links to relevant resources (such as manuals, research papers, etc.), links to relevant forum discussions on the topic, book titles, or anything that might be useful.
What follows is very much a work in progress.
?
Adding to the Wiki
For those unfamiliar with the Wiki phenomenon, it is basically a user editable encyclopedia. The idea is that there are pages with different articles, which the user can read and also choose to edit if desired. If a piece of information is incorrect, a link outdated, or the presentation choppy or unclear, the user can just click "Edit Page" at the bottom and then fix the mistake. There is also a "Page History," so if you a user were to make a mistake or maliciously destroy a page (which wouldn't happen here) an editor can come along and restore the page to a previous version.?
If you have used MediaWiki (the engine that runs behind the scene of Wikipedia.org) you will be familiar with a certain style of creating an article. There are tags that one uses to change the formatting of the parts of the article. The Wiki on Groups.io uses a different background engine and so the standard MediaWiki syntax does not apply here. Rather, the page is edited using the same tools as one would use to compose a message on the forums. If you are a programmer or someone who likes using the tagged syntax directly, you can access the underlying page source code, be activating the advanced editing toolbar (the icon with three lines on the far right of the basic toolbar) and then clicking on the source code icon <> on the far right of the Advance Editing Toolbar. You will immediately notice that the underlying source code is HTML. Most things can be done just by using the various icons, but advanced features like table can only be implemented by manually writing the source code. (Although there are website available that will generate the source code for you through a graphical interface.)
This section describes the hardware used for XRF. We will describe the basic theory of operation of each stage in the processing tool chain and then present different commercial systems that are available as these systems are often integrated together.
[Editor note: General theory needs to be in an independent page separate from specific manufacturer information.
[Editor note - question: Should this be arranged by category, e.g detectors, preamps, etc or by manufacturer with the manufacturers product line on one page. Perhaps it's best to put a list of products with theory but the details of the products on a manufacture page...]
Detectors?- what's available, theory of operation, tradeoffs
Detector Cooling?- keeping detectors cool to avoid thermal noise and keeping the TEC from overheating
Preamps?- theory of operation, brief summary of what out there (and what not to do - such as trying to use a PMT preamp for a SiPIN diode...)
Pulse Processing Theory - high level overview of the stages of going from detector pulse to channel peaks on the computer
Commercial Systems - many commercial systems are integrated so it seems to make sense to present, for example all Amptek products together. [question: are their other affordable integrated systems besides Amptek?]
Dud, here are the .mca files along with another one that I did of Nb last night.? I would be interested in seeing what calibration points you can come up with.? These were scanned on different days.? It takes hours to create each scan so there is no point in trying to recalibrate each day.? If this Si-PIN has any drift I have not been able to detect it.
"Dud, I made a special decluttered plot just for you.? And in the process I discovered that the SmKa1 peak that I had previously identified is actually CeKb2 so this Ce metal is actually a little purer than I thought!
Charles"
Be sure to pay attention to L-gamma and M- shell lines too.?
Geo
----- Original Message ----- From: Charles David Young <charlesdavidyoung@...> To: [email protected] Sent: Wed, 04 Mar 2020 23:07:58 -0500 (EST) Subject: Re: [XRF] Si-PIN with a view
Ok, so the deal is that using AgKa1 as one of the points on the E cal line is not very accurate by the time it gets up to CeKa1 so the peak finder in DppMCA
assumed that peak was BaKa1.? Use these cal points instead in DppMCA:
2955 34.72
270 2.98
You may ask why I never noticed this discrepancy?? The reason is that I use DppMCA strictly for collecting data.? The E cal in DppMCA is not critical.? All analysis is done in my highly customized Theremino where I can label things nicely.? The table format of DppMCA just doesn't cut it for me.
Dud, I made a special decluttered plot just for you.? And in the process I discovered that the SmKa1 peak that I had previously identified is actually CeKb2 so this Ce metal is actually a little purer than I thought!
Charles
On Wed, Mar 4, 2020 at 2:44 PM Dude <dfemer@...> wrote:
Charles,
Check your ¡°slider¡± calibration. This is Ba not Ce. Go back to the .mca file and look at it with the original cal using the DppMCA program. It looks like you used Ag for a cal but when was that cal done? Before you ran the ¡°Ce¡± or was it an old one?
Please clean up the theremino plot, you have so many lines and labels on their it¡¯s hard to tell what is what. Get rid of anything that¡¯s not ID¡¯d or an interference anything else is clutter.? One shouldn¡¯t ?do an interp based on pre-established labels. Treat each peak separately starting at the low energy and work your way up ruling out close interferences. Then put an ROI and ?ID label on it and use a real MCA program.? Thermino is great for NaI but it¡¯ll get you in trouble with these high res detectors.
There is no Sm , La or Ce in here and it looks like you were at 83% dead time which is too high which can shift energy and FWHM.
Think scientifically. The hypothesis was its Ce. You need to prove that.? I¡¯ll guess you used your pre-established Ce labels and did the ¡°slider¡± thing to line it all up to a preconceived notion. ??Wrong approach and guaranteed to get you in trouble- Don¡¯t use a secondary Cal - use the data acquisition program to ID peaks.? Look at the periodic table ¨C Ba, La, and Ce line up so they are going to have the same spectral structure close energies and look alike if the cal isn¡¯t right.? An interp starts by looking at each individual peak energy and any surrounding interferences with no pre-conceived notions, then decide based on Ka,b and La,b and move on to the next. If it doesn¡¯t take you an hour or more you¡¯re not doing it right. Computer picks suck, stay a long way away ¨C use your eyes, brains and an energy table.
This is from Gunnar Faerber who did his own analysis.? He is also the one that identified the Betafo speciman as brannerite.
?
?
Meanwhile, this is an interesting scan of Ce metal.? It is evidently hard to purify it of the other lanthanides because it shows plenty of Sm and even detectable La.? The La1 and Lb1 peaks echo the Ka1 and Kb1 peaks nicely.? Taken together this set of peaks is quite useful for calibration from low to high.
?
Charles
?
On Tue, Mar 3, 2020 at 9:03 PM WILLIAM S Dubyk <sdubyk@...> wrote:
Charles, who did you get your specimen of ishikawaite from, and do you have a microprobe analysis for it? The reason I ask is that out of curiosity I looked at some of the samarskite analyses from the Petaca district, and several of the Queen mine specimens may be that mineral. I will ask Al Falster, who is somewhat of an expert on the samarskite minerals, about what analyses to use to determine this - oxides versus cation ratios. From my understanding, this mineral has U+Th greater than Y+REE, and that is what I see in the Queen mine specimens.
I
agree the library is sparse and it doesn¡¯t have both La,b and Ka,b In one library. The auto
peak search routine sucks on noisy data and is hard to tweak. Its best to set
ROI¡¯s manually once you¡¯ve ID¡¯d the peak. It is easy add and make custom
libraries though.
The
DPP Libraries are too general, causing confusion and miss labeling a lot. I've
been making specialty .lib files with special combinations of elements, XRF
lines and Gamma lines. Very few elements in each, but related. They already
have a few like that called "Accident" and "Sources".
?
Geo
?
-----
Original Message -----
From: Charles David Young <charlesdavidyoung@...>
To: [email protected]
Sent: Wed, 04 Mar 2020 23:07:58 -0500 (EST)
Subject: Re: [XRF] Si-PIN with a view
?
Ok,
so the deal is that using AgKa1 as one of the points on the E cal line is not
very accurate by the time it gets up to CeKa1 so the peak finder in DppMCA
?
assumed
that peak was BaKa1.? Use these cal points instead in DppMCA:
?
2955
34.72
270
2.98
?
You
may ask why I never noticed this discrepancy?? The reason is that I use
DppMCA strictly for collecting data.? The E cal in DppMCA is not
critical.? All analysis is done in my highly customized Theremino where I
can label things nicely.? The table format of
DppMCA just doesn't cut it for me.
?
Dud,
I made a special decluttered plot just for you.? And in the process I
discovered that the SmKa1 peak that I had previously identified is actually
CeKb2 so this Ce metal is actually a little purer than I thought!
?
Charles
?
On
Wed, Mar 4, 2020 at 2:44 PM Dude <dfemer@...> wrote:
Charles,
Check
your ¡°slider¡± calibration. This is Ba not Ce. Go back to the
.mca file and look at it with the original cal using the DppMCA program. It
looks like you used Ag for a cal but when was that cal done? Before you ran the
¡°Ce¡± or was it an old one?
Please
clean up the theremino plot, you have so many lines and
labels on their it¡¯s hard to tell what is what. Get rid of anything that¡¯s not
ID¡¯d or an interference anything else is clutter.? One shouldn¡¯t ?do
an interp
based on pre-established labels. Treat each peak separately starting at the low
energy and work your way up ruling out close interferences. Then put an ROI and
?ID label on it and use a real MCA program.? Thermino is great for
NaI but it¡¯ll
get you in trouble with these high res detectors.
There
is no Sm , La or Ce in here and it looks like you were at
83% dead time which is too high which can shift energy and FWHM.
Think
scientifically. The hypothesis was its Ce. You need to prove
that.? I¡¯ll guess you used your pre-established Ce labels and did the
¡°slider¡±
thing to line it all up to a preconceived notion. ??Wrong approach
and guaranteed
to get you in trouble- Don¡¯t use a secondary Cal - use the data acquisition
program to ID peaks.? Look at the periodic table ¨C Ba, La, and Ce line up
so
they are going to have the same spectral structure close energies and look
alike if the cal isn¡¯t right.? An interp starts by looking at each
individual peak
energy and any surrounding interferences with no pre-conceived notions, then
decide
based on Ka,b and La,b and move on to the next. If it doesn¡¯t take you an hour
or more you¡¯re not doing it right. Computer picks suck, stay a long way away ¨C
use your eyes, brains and an energy table.
This is from Gunnar Faerber who did his own analysis.?
He is also the one that identified the Betafo speciman as brannerite.
?
?
Meanwhile, this is an interesting scan of Ce metal.?
It
is evidently hard to purify it of the other lanthanides because it shows plenty
of Sm and even detectable La.? The La1 and Lb1 peaks echo the Ka1 and Kb1
peaks nicely.? Taken together this set of peaks is quite useful for
calibration from low to high.
?
Charles
?
On Tue, Mar 3, 2020 at 9:03 PM WILLIAM S Dubyk <sdubyk@...> wrote:
Charles, who did you get your specimen of ishikawaite from,
and do you have a microprobe analysis for it? The reason I ask is that out of
curiosity I looked at some of the samarskite analyses from the Petaca district,
and several of the Queen mine specimens may be that mineral. I will ask Al
Falster, who is somewhat of an expert on the samarskite minerals, about what
analyses to use to determine this - oxides versus cation ratios. From my
understanding, this mineral has U+Th greater than Y+REE, and that is what I see
in the Queen mine specimens.
"Dud, I made a special decluttered plot just for you.? And in the process I discovered that the SmKa1 peak that I had previously identified is actually CeKb2 so this Ce metal is actually a little purer than I thought!
Charles"
Be sure to pay attention to L-gamma and M- shell lines too.?
----- Original Message ----- From: Charles David Young <charlesdavidyoung@...> To: [email protected] Sent: Wed, 04 Mar 2020 23:07:58 -0500 (EST) Subject: Re: [XRF] Si-PIN with a view
Ok, so the deal is that using AgKa1 as one of the points on the E cal line is not very accurate by the time it gets up to CeKa1 so the peak finder in DppMCA
assumed that peak was BaKa1.? Use these cal points instead in DppMCA:
2955 34.72
270 2.98
You may ask why I never noticed this discrepancy?? The reason is that I use DppMCA strictly for collecting data.? The E cal in DppMCA is not critical.? All analysis is done in my highly customized Theremino where I can label things nicely.? The table format of DppMCA just doesn't cut it for me.
Dud, I made a special decluttered plot just for you.? And in the process I discovered that the SmKa1 peak that I had previously identified is actually CeKb2 so this Ce metal is actually a little purer than I thought!
Charles
On Wed, Mar 4, 2020 at 2:44 PM Dude <dfemer@...> wrote:
Charles,
Check your ¡°slider¡± calibration. This is Ba not Ce. Go back to the .mca file and look at it with the original cal using the DppMCA program. It looks like you used Ag for a cal but when was that cal done? Before you ran the ¡°Ce¡± or was it an old one?
Please clean up the theremino plot, you have so many lines and labels on their it¡¯s hard to tell what is what. Get rid of anything that¡¯s not ID¡¯d or an interference anything else is clutter.? One shouldn¡¯t ?do an interp based on pre-established labels. Treat each peak separately starting at the low energy and work your way up ruling out close interferences. Then put an ROI and ?ID label on it and use a real MCA program.? Thermino is great for NaI but it¡¯ll get you in trouble with these high res detectors.
There is no Sm , La or Ce in here and it looks like you were at 83% dead time which is too high which can shift energy and FWHM.
Think scientifically. The hypothesis was its Ce. You need to prove that.? I¡¯ll guess you used your pre-established Ce labels and did the ¡°slider¡± thing to line it all up to a preconceived notion. ??Wrong approach and guaranteed to get you in trouble- Don¡¯t use a secondary Cal - use the data acquisition program to ID peaks.? Look at the periodic table ¨C Ba, La, and Ce line up so they are going to have the same spectral structure close energies and look alike if the cal isn¡¯t right.? An interp starts by looking at each individual peak energy and any surrounding interferences with no pre-conceived notions, then decide based on Ka,b and La,b and move on to the next. If it doesn¡¯t take you an hour or more you¡¯re not doing it right. Computer picks suck, stay a long way away ¨C use your eyes, brains and an energy table.
This is from Gunnar Faerber who did his own analysis.? He is also the one that identified the Betafo speciman as brannerite.
?
?
Meanwhile, this is an interesting scan of Ce metal.? It is evidently hard to purify it of the other lanthanides because it shows plenty of Sm and even detectable La.? The La1 and Lb1 peaks echo the Ka1 and Kb1 peaks nicely.? Taken together this set of peaks is quite useful for calibration from low to high.
?
Charles
?
On Tue, Mar 3, 2020 at 9:03 PM WILLIAM S Dubyk <sdubyk@...> wrote:
Charles, who did you get your specimen of ishikawaite from, and do you have a microprobe analysis for it? The reason I ask is that out of curiosity I looked at some of the samarskite analyses from the Petaca district, and several of the Queen mine specimens may be that mineral. I will ask Al Falster, who is somewhat of an expert on the samarskite minerals, about what analyses to use to determine this - oxides versus cation ratios. From my understanding, this mineral has U+Th greater than Y+REE, and that is what I see in the Queen mine specimens.
The DPP Libraries are too general, causing confusion and miss labeling a lot. I've been making specialty .lib files with special combinations of elements, XRF lines and Gamma lines. Very few elements in each, but related. They already have a few like that called "Accident" and "Sources".
----- Original Message ----- From: Charles David Young <charlesdavidyoung@...> To: [email protected] Sent: Wed, 04 Mar 2020 23:07:58 -0500 (EST) Subject: Re: [XRF] Si-PIN with a view
Ok, so the deal is that using AgKa1 as one of the points on the E cal line is not very accurate by the time it gets up to CeKa1 so the peak finder in DppMCA
assumed that peak was BaKa1.? Use these cal points instead in DppMCA:
2955 34.72
270 2.98
You may ask why I never noticed this discrepancy?? The reason is that I use DppMCA strictly for collecting data.? The E cal in DppMCA is not critical.? All analysis is done in my highly customized Theremino where I can label things nicely.? The table format of DppMCA just doesn't cut it for me.
Dud, I made a special decluttered plot just for you.? And in the process I discovered that the SmKa1 peak that I had previously identified is actually CeKb2 so this Ce metal is actually a little purer than I thought!
Charles
On Wed, Mar 4, 2020 at 2:44 PM Dude <dfemer@...> wrote:
Charles,
Check your ¡°slider¡± calibration. This is Ba not Ce. Go back to the .mca file and look at it with the original cal using the DppMCA program. It looks like you used Ag for a cal but when was that cal done? Before you ran the ¡°Ce¡± or was it an old one?
Please clean up the theremino plot, you have so many lines and labels on their it¡¯s hard to tell what is what. Get rid of anything that¡¯s not ID¡¯d or an interference anything else is clutter.? One shouldn¡¯t ?do an interp based on pre-established labels. Treat each peak separately starting at the low energy and work your way up ruling out close interferences. Then put an ROI and ?ID label on it and use a real MCA program.? Thermino is great for NaI but it¡¯ll get you in trouble with these high res detectors.
There is no Sm , La or Ce in here and it looks like you were at 83% dead time which is too high which can shift energy and FWHM.
Think scientifically. The hypothesis was its Ce. You need to prove that.? I¡¯ll guess you used your pre-established Ce labels and did the ¡°slider¡± thing to line it all up to a preconceived notion. ??Wrong approach and guaranteed to get you in trouble- Don¡¯t use a secondary Cal - use the data acquisition program to ID peaks.? Look at the periodic table ¨C Ba, La, and Ce line up so they are going to have the same spectral structure close energies and look alike if the cal isn¡¯t right.? An interp starts by looking at each individual peak energy and any surrounding interferences with no pre-conceived notions, then decide based on Ka,b and La,b and move on to the next. If it doesn¡¯t take you an hour or more you¡¯re not doing it right. Computer picks suck, stay a long way away ¨C use your eyes, brains and an energy table.
This is from Gunnar Faerber who did his own analysis.? He is also the one that identified the Betafo speciman as brannerite.
?
?
Meanwhile, this is an interesting scan of Ce metal.? It is evidently hard to purify it of the other lanthanides because it shows plenty of Sm and even detectable La.? The La1 and Lb1 peaks echo the Ka1 and Kb1 peaks nicely.? Taken together this set of peaks is quite useful for calibration from low to high.
?
Charles
?
On Tue, Mar 3, 2020 at 9:03 PM WILLIAM S Dubyk <sdubyk@...> wrote:
Charles, who did you get your specimen of ishikawaite from, and do you have a microprobe analysis for it? The reason I ask is that out of curiosity I looked at some of the samarskite analyses from the Petaca district, and several of the Queen mine specimens may be that mineral. I will ask Al Falster, who is somewhat of an expert on the samarskite minerals, about what analyses to use to determine this - oxides versus cation ratios. From my understanding, this mineral has U+Th greater than Y+REE, and that is what I see in the Queen mine specimens.
Ok, so the deal is that using AgKa1 as one of the points on
the E cal line is not very accurate by the time it gets up to CeKa1 so the peak
finder in DppMCA assumed that peak was BaKa1.? Use these cal points
instead in DppMCA:
?
2955 34.72
270 2.98
?
You may ask why I never noticed this discrepancy?? The
reason is that I use DppMCA strictly for collecting data.? The E cal in
DppMCA is not critical.? All analysis is done in my highly customized
Theremino where I can label things nicely.? The table format of DppMCA
just doesn't cut it for me.
?
Dud, I made a special decluttered plot just for you.?
And in the process I discovered that the SmKa1 peak that I had previously
identified is actually CeKb2 so this Ce metal is actually a little purer than I
thought!
?
Charles
?
On Wed, Mar 4, 2020 at 2:44 PM Dude <dfemer@...> wrote:
Charles,
Check
your ¡°slider¡± calibration. This is Ba not Ce. Go back to the .mca file and look
at it with the original cal using the DppMCA program. It looks like you used Ag
for a cal but when was that cal done? Before you ran the ¡°Ce¡± or was it an old
one?
Please
clean up the theremino plot, you have so many lines and labels on their it¡¯s
hard to tell what is what. Get rid of anything that¡¯s not ID¡¯d or an
interference anything else is clutter.? One shouldn¡¯t ?do an interp
based on pre-established labels. Treat each peak separately starting at the low
energy and work your way up ruling out close interferences. Then put an ROI and
?ID label on it and use a real MCA program.? Thermino is great for
NaI but it¡¯ll get you in trouble with these high res detectors.
There
is no Sm , La or Ce in here and it looks like you were at 83% dead time which
is too high which can shift energy and FWHM.
Think
scientifically. The hypothesis was its Ce. You need to prove that.? I¡¯ll
guess you used your pre-established Ce labels and did the ¡°slider¡± thing to
line it all up to a preconceived notion. ??Wrong approach and
guaranteed to get you in trouble- Don¡¯t use a secondary Cal - use the data
acquisition program to ID peaks.? Look at the periodic table ¨C Ba, La, and
Ce line up so they are going to have the same spectral structure close energies
and look alike if the cal isn¡¯t right.? An interp starts by looking at
each individual peak energy and any surrounding interferences with no
pre-conceived notions, then decide based on Ka,b and La,b and move on to the next.
If it doesn¡¯t take you an hour or more you¡¯re not doing it right. Computer
picks suck, stay a long way away ¨C use your eyes, brains and an energy table.
This
is from Gunnar Faerber who did his own analysis.? He is also the one that
identified the Betafo speciman as brannerite.
?
?
Meanwhile,
this is an interesting scan of Ce metal.? It is evidently hard to purify
it of the other lanthanides because it shows plenty of Sm and even detectable La.?
The La1 and Lb1 peaks echo the Ka1 and Kb1 peaks nicely.? Taken together
this set of peaks is quite useful for calibration from low to high.
?
Charles
?
On
Tue, Mar 3, 2020 at 9:03 PM WILLIAM S Dubyk <sdubyk@...> wrote:
Charles,
who did you get your specimen of ishikawaite from, and do you have a microprobe
analysis for it? The reason I ask is that out of curiosity I looked at some of
the samarskite analyses from the Petaca district, and several of the Queen mine
specimens may be that mineral. I will ask Al Falster, who is somewhat of an
expert on the samarskite minerals, about what analyses to use to determine this
- oxides versus cation ratios. From my understanding, this mineral has U+Th
greater than Y+REE, and that is what I see in the Queen mine specimens.
Ok, so the deal is that using AgKa1 as one of the points on the E cal line is not very accurate by the time it gets up to CeKa1 so the peak finder in DppMCA
assumed that peak was BaKa1.? Use these cal points instead in DppMCA:
2955 34.72
270 2.98
You may ask why I never noticed this discrepancy?? The reason is that I use DppMCA strictly for collecting data.? The E cal in DppMCA is not critical.? All analysis is done in my highly customized Theremino where I can label things nicely.? The table format of
DppMCA just doesn't cut it for me.
Dud, I made a special decluttered plot just for you.? And in the process I discovered that the SmKa1 peak that I had previously identified is actually CeKb2 so this Ce metal is actually a little purer than I thought!
On Wed, Mar 4, 2020 at 2:44 PM Dude <dfemer@...> wrote:
Charles,
Check your ¡°slider¡± calibration. This is Ba not Ce. Go back to the
.mca file and look at it with the original cal using the DppMCA program. It
looks like you used Ag for a cal but when was that cal done? Before you ran the
¡°Ce¡± or was it an old one?
Please clean up the theremino plot, you have so many lines and
labels on their it¡¯s hard to tell what is what. Get rid of anything that¡¯s not
ID¡¯d or an interference anything else is clutter.? One shouldn¡¯t ?do an interp
based on pre-established labels. Treat each peak separately starting at the low
energy and work your way up ruling out close interferences. Then put an ROI and
?ID label on it and use a real MCA program.? Thermino is great for NaI but it¡¯ll
get you in trouble with these high res detectors.
There is no Sm , La or Ce in here and it looks like you were at
83% dead time which is too high which can shift energy and FWHM.
Think scientifically. The hypothesis was its Ce. You need to prove
that.? I¡¯ll guess you used your pre-established Ce labels and did the ¡°slider¡±
thing to line it all up to a preconceived notion. ??Wrong approach and guaranteed
to get you in trouble- Don¡¯t use a secondary Cal - use the data acquisition
program to ID peaks.? Look at the periodic table ¨C Ba, La, and Ce line up so
they are going to have the same spectral structure close energies and look
alike if the cal isn¡¯t right.? An interp starts by looking at each individual peak
energy and any surrounding interferences with no pre-conceived notions, then decide
based on Ka,b and La,b and move on to the next. If it doesn¡¯t take you an hour
or more you¡¯re not doing it right. Computer picks suck, stay a long way away ¨C
use your eyes, brains and an energy table.
This is from Gunnar Faerber who did his own analysis.?
He is also the one that identified the Betafo speciman as brannerite.
?
?
Meanwhile, this is an interesting scan of Ce metal.? It
is evidently hard to purify it of the other lanthanides because it shows plenty
of Sm and even detectable La.? The La1 and Lb1 peaks echo the Ka1 and Kb1
peaks nicely.? Taken together this set of peaks is quite useful for
calibration from low to high.
?
Charles
?
On Tue, Mar 3, 2020 at 9:03 PM WILLIAM S Dubyk <sdubyk@...> wrote:
Charles, who did you get your specimen of ishikawaite from,
and do you have a microprobe analysis for it? The reason I ask is that out of
curiosity I looked at some of the samarskite analyses from the Petaca district,
and several of the Queen mine specimens may be that mineral. I will ask Al
Falster, who is somewhat of an expert on the samarskite minerals, about what
analyses to use to determine this - oxides versus cation ratios. From my
understanding, this mineral has U+Th greater than Y+REE, and that is what I see
in the Queen mine specimens.
Check your ¡°slider¡± calibration. This is Ba not Ce. Go back to the
.mca file and look at it with the original cal using the DppMCA program. It
looks like you used Ag for a cal but when was that cal done? Before you ran the
¡°Ce¡± or was it an old one?
Please clean up the theremino plot, you have so many lines and
labels on their it¡¯s hard to tell what is what. Get rid of anything that¡¯s not
ID¡¯d or an interference anything else is clutter. ?One shouldn¡¯t ?do an interp
based on pre-established labels. Treat each peak separately starting at the low
energy and work your way up ruling out close interferences. Then put an ROI and
?ID label on it and use a real MCA program.? Thermino is great for NaI but it¡¯ll
get you in trouble with these high res detectors.
There is no Sm , La or Ce in here and it looks like you were at
83% dead time which is too high which can shift energy and FWHM.
Think scientifically. The hypothesis was its Ce. You need to prove
that. ?I¡¯ll guess you used your pre-established Ce labels and did the ¡°slider¡±
thing to line it all up to a preconceived notion. ??Wrong approach and guaranteed
to get you in trouble- Don¡¯t use a secondary Cal - use the data acquisition
program to ID peaks. ?Look at the periodic table ¨C Ba, La, and Ce line up so
they are going to have the same spectral structure close energies and look
alike if the cal isn¡¯t right. ?An interp starts by looking at each individual peak
energy and any surrounding interferences with no pre-conceived notions, then decide
based on Ka,b and La,b and move on to the next. If it doesn¡¯t take you an hour
or more you¡¯re not doing it right. Computer picks suck, stay a long way away ¨C
use your eyes, brains and an energy table.
This is from Gunnar Faerber who did his own analysis.?
He is also the one that identified the Betafo speciman as brannerite.
?
?
Meanwhile, this is an interesting scan of Ce metal.? It
is evidently hard to purify it of the other lanthanides because it shows plenty
of Sm and even detectable La.? The La1 and Lb1 peaks echo the Ka1 and Kb1
peaks nicely.? Taken together this set of peaks is quite useful for
calibration from low to high.
?
Charles
?
On Tue, Mar 3, 2020 at 9:03 PM WILLIAM S Dubyk <sdubyk@...> wrote:
Charles, who did you get your specimen of ishikawaite from,
and do you have a microprobe analysis for it? The reason I ask is that out of
curiosity I looked at some of the samarskite analyses from the Petaca district,
and several of the Queen mine specimens may be that mineral. I will ask Al
Falster, who is somewhat of an expert on the samarskite minerals, about what
analyses to use to determine this - oxides versus cation ratios. From my
understanding, this mineral has U+Th greater than Y+REE, and that is what I see
in the Queen mine specimens.
----- Original Message ----- From: Charles David Young <charlesdavidyoung@...> To: [email protected] Sent: Wed, 04 Mar 2020 07:25:08 -0500 (EST) Subject: Re: [XRF] Si-PIN with a view
Steve,
This is from Gunnar Faerber who did his own analysis.? He is also the one that identified the Betafo speciman as brannerite.
Meanwhile, this is an interesting scan of Ce metal.? It is evidently hard to purify it of the other lanthanides because it shows plenty of Sm and even detectable La.? The La1 and Lb1 peaks echo the Ka1 and Kb1 peaks nicely.? Taken together this set of peaks is quite useful for calibration from low to high.
Charles
On Tue, Mar 3, 2020 at 9:03 PM WILLIAM S Dubyk <sdubyk@...> wrote:
Charles, who did you get your specimen of ishikawaite from, and do you have a microprobe analysis for it? The reason I ask is that out of curiosity I looked at some of the samarskite analyses from the Petaca district, and several of the Queen mine specimens may be that mineral. I will ask Al Falster, who is somewhat of an expert on the samarskite minerals, about what analyses to use to determine this - oxides versus cation ratios. From my understanding, this mineral has U+Th greater than Y+REE, and that is what I see in the Queen mine specimens.
----- Original Message ----- From: Charles David Young <charlesdavidyoung@...> To: [email protected] Sent: Wed, 04 Mar 2020 07:25:08 -0500 (EST) Subject: Re: [XRF] Si-PIN with a view
Steve,
This is from Gunnar Faerber who did his own analysis.? He is also the one that identified the Betafo speciman as brannerite.
Meanwhile, this is an interesting scan of Ce metal.? It is evidently hard to purify it of the other lanthanides because it shows plenty of Sm and even detectable La.? The La1 and Lb1 peaks echo the Ka1 and Kb1 peaks nicely.? Taken together this set of peaks is quite useful for calibration from low to high.
Charles
On Tue, Mar 3, 2020 at 9:03 PM WILLIAM S Dubyk <sdubyk@...> wrote:
Charles, who did you get your specimen of ishikawaite from, and do you have a microprobe analysis for it? The reason I ask is that out of curiosity I looked at some of the samarskite analyses from the Petaca district, and several of the Queen mine specimens may be that mineral. I will ask Al Falster, who is somewhat of an expert on the samarskite minerals, about what analyses to use to determine this - oxides versus cation ratios. From my understanding, this mineral has U+Th greater than Y+REE, and that is what I see in the Queen mine specimens.
This is from Gunnar Faerber who did his own analysis.? He is also the one that identified the Betafo speciman as brannerite.
Meanwhile, this is an interesting scan of Ce metal.? It is evidently hard to purify it of the other lanthanides because it shows plenty of Sm and even detectable La.? The La1 and Lb1 peaks echo the Ka1 and Kb1 peaks nicely.? Taken together this set of peaks is quite useful for calibration from low to high.
On Tue, Mar 3, 2020 at 9:03 PM WILLIAM S Dubyk <sdubyk@...> wrote:
Charles, who did you get your specimen of ishikawaite from, and do you have a microprobe analysis for it? The reason I ask is that out of curiosity I looked at some of the samarskite analyses from the Petaca district, and several of the Queen mine specimens may be that mineral. I will ask Al Falster, who is somewhat of an expert on the samarskite minerals, about what analyses to use to determine this - oxides versus cation ratios. From my understanding, this mineral has U+Th greater than Y+REE, and that is what I see in the Queen mine specimens.
Charles, who did you get your specimen of ishikawaite from, and do you have a microprobe analysis for it? The reason I ask is that out of curiosity I looked at some of the samarskite analyses from the Petaca district, and several of the Queen mine specimens may be that mineral. I will ask Al Falster, who is somewhat of an expert on the samarskite minerals, about what analyses to use to determine this - oxides versus cation ratios. From my understanding, this mineral has U+Th greater than Y+REE, and that is what I see in the Queen mine specimens.
This chart is from an article (attributed below) showing the mass spectrometer analysis of ordinary Trinity area desert sand contains 0.62% FeO and only 0.02% SrO in its natural state.
"A synchrotron X-ray spectroscopy study of titanium co-ordination in explosive melt glass derived from the trinity nuclear test"?
That would be a question better for BELLJAR GROUP I think. Personally I use a commercial exciter, it is very safe in every respect, the HV is generated inside the head, only 12V goes from the control box.
----- Original Message ----- From: taray singh via Groups.Io <sukhjez@...> To: [email protected] Sent: Mon, 02 Mar 2020 23:55:44 -0500 (EST) Subject: Re: [XRF] Zircon- Malawi vs Sri Lanka
Geo My setup HV is fixed at about 30 kvp. So I do not measure it. Do you ground ur any of ur ?electrodes ? Taray
----- Original Message ----- From: taray singh via Groups.Io <sukhjez@...> To: [email protected] Sent: Tue, 03 Mar 2020 04:24:24 -0500 (EST) Subject: Re: [XRF] Zircon- Malawi vs Sri Lanka
Geo
My multimeter max is 1000ohm
Theoretically for??HV measurements ,If I place a 1000 ohm resistor in series with my sensor,I should be able to ..
Potential danger of arcing and inexperience is stopping me
No I mean measure the beam itself with your sensor. Look at the Bremsstrahlung bump. Where it ends is the max HV, very easy, but reduce sensitivity of the probe with Pb and a tiny hole, like a collimator.
----- Original Message ----- From: taray singh via Groups.Io <sukhjez@...> To: [email protected] Sent: Tue, 03 Mar 2020 04:24:24 -0500 (EST) Subject: Re: [XRF] Zircon- Malawi vs Sri Lanka
Geo
My multimeter max is 1000ohm
Theoretically for??HV measurements ,If I place a 1000 ohm resistor in series with my sensor,I should be able to ..
Potential danger of arcing and inexperience is stopping me
----- Original Message ----- From: taray singh via Groups.Io <sukhjez@...> To: [email protected] Sent: Mon, 02 Mar 2020 21:34:33 -0500 (EST) Subject: Re: [XRF] Zircon- Malawi vs Sri Lanka
Hi guys?
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. U..
Couldn¡¯t agree more?
If lower Z element is present in sufficient quantities ,higher energies??will still have a higher probability to??xrf low Z elements?
?
Only issue is minimizing??the??bg noise??when using lower energies .
Anyone successfully grounded his cathode to generate more low energy x rays .Good for low Z elements?
