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 If a piece of information is incorrect, a link outdated, or the presentation choppy or unclear, the user can just click "Edit Page" at the bottom and then fix the mistake.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?]
What is interesting is the ratio of intensity of 235/238. Of course, nuclide production, decay activity and contribution of Unat must be considered but it still seems off.
He did weigh the sample Steve, but then he digested it in Hydrofluoric and Nitric acid. after drying he must have measured it again? Anyhow I don't know but would guess yes they can do that.
----- Original Message -----
From: WILLIAM S Dubyk <sdubyk@...>
To: [email protected]
Sent: Tue, 29 Sep 2020 19:11:59 -0400 (EDT)
Subject: Re: [XRF] Trinitite
Is there any way to convert intensity to ppm or ppt?
"Neptunium", a YouTuber did an ICPMS mass-spectrum? of Trinitite.
From the data presented on isotope ratios these are of most interest to us:
Analysis? ? ?Intensity
? U-235? ? ? ? ? ?1523.1
? U-238? ? ? ?235679.6??
? Pu-239? ? ? ? ?6312.2
? Pu-240? ? ? ? ? ?167.5
? Pu-241? ? ? ? ? ? ? ?3.6?
Good to know. He did multiple runs, they were statistically the same.
We can start to make preliminary assumptions based on known T/2 of the isotopes and their daughters.
Pu-239 by far the most abundant species.?
Pu-241 is only T/2= 14.4 years so it's remarkable there is any left now. It decays 100% to Am-241 so we can get a calculation of it's T=0 quantity.
Pu-243 would have decayed away in one day, but it's 100% progeny Am-243 lasts a long time, so we have to at least consider the one report that identifies Am-243 as possible, while at the same time investigate the alternatives.
All-in-all we can probably claim a good half dozen X-Ray peaks to our personal Life-Lists, and either prove or debunk a few prior claims by others.
He did weigh the sample Steve, but then he digested it in Hydrofluoric and Nitric acid. after drying he must have measured it again? Anyhow I don't know but would guess yes they can do that.
"Neptunium", a YouTuber did an ICPMS mass-spectrum? of Trinitite.
From the data presented on isotope ratios these are of most interest to us:
Analysis? ? ?Intensity
? U-235? ? ? ? ? ?1523.1
? U-238? ? ? ?235679.6??
? Pu-239? ? ? ? ?6312.2
? Pu-240? ? ? ? ? ?167.5
? Pu-241? ? ? ? ? ? ? ?3.6?
Good to know. He did multiple runs, they were statistically the same.
We can start to make preliminary assumptions based on known T/2 of the isotopes and their daughters.
Pu-239 by far the most abundant species.?
Pu-241 is only T/2= 14.4 years so it's remarkable there is any left now. It decays 100% to Am-241 so we can get a calculation of it's T=0 quantity.
Pu-243 would have decayed away in one day, but it's 100% progeny Am-243 lasts a long time, so we have to at least consider the one report that identifies Am-243 as possible, while at the same time investigate the alternatives.
All-in-all we can probably claim a good half dozen X-Ray peaks to our personal Life-Lists, and either prove or debunk a few prior claims by others.
Good to know. He did multiple runs, they were statistically the same.
We can start to make preliminary assumptions based on known T/2 of the isotopes and their daughters.
Pu-239 by far the most abundant species.?
Pu-241 is only T/2= 14.4 years so it's remarkable there is any left now. It decays 100% to Am-241 so we can get a calculation of it's T=0 quantity.
Pu-243 would have decayed away in one day, but it's 100% progeny Am-243 lasts a long time, so we have to at least consider the one report that identifies Am-243 as possible, while at the same time investigate the alternatives.
All-in-all we can probably claim a good half dozen X-Ray peaks to our personal Life-Lists, and either prove or debunk a few prior claims by others.
Good to know. He did multiple runs, they were statistically the same.
We can start to make preliminary assumptions based on known T/2 of the isotopes and their daughters.
Pu-239 by far the most abundant species.?
Pu-241 is only T/2= 14.4 years so it's remarkable there is any left now. It decays 100% to Am-241 so we can get a calculation of it's T=0 quantity.
Pu-243 would have decayed away in one day, but it's 100% progeny Am-243 lasts a long time, so we have to at least consider the one report that identifies Am-243 as possible, while at the same time investigate the alternatives.
All-in-all we can probably claim a good half dozen X-Ray peaks to our personal Life-Lists, and either prove or debunk a few prior claims by others.
I
think you’ve gone as far as you can without calculating a Pu concentration from
the Am and determining the x-ray yields. The Pu derived U x-ray peaks of La1, Lb1,
Lg1 and Ll you see in the spectra are enough evidence for the presence Pu 238,
239, 240 and 241 as there are no interfering x-rays. Any U decay Th x-ray’s are
going to be very hard to detect due to the long half life and low yield at 93.1
keV.
A closer look at a Gamma RaySpectrum scan of Red
Trinitite? (see pics in first post of this thread).
The picture and .mca attached are of a previous (19FED2020) scan of Red
Trinitite
In the photo you are seeing an automatic peak search identifying the lowest
major X-Ray
as being 13.6? which is of course the La1 line of Uranium. Many other
scans using higher energy?
probes don't indicate the presence of significant, especially the first few
daughters in the various U isotope's decay chains (U-234, U-235, U238)
Hundreds, even thousands of Trinitite Gamma Scans show the 3 X-Ray peaks,
universally identified as U-X-Rays or U-Pb X-Rays or even Am-241 X-Rays. They
are indeed U X-Rays, all 3 are there- U- La1, Lb1, Ly1.? It is my goal to
prove them to be from the decay of Pu to Uranium, especially Pu-239>U-235.
Let's walk through Uranium Radioactive Decay Schemes, one U isotope at a time to clarify the? reason we see certain peaks on spectroscopy scans.
We use the convention in this science that:
X-Rays are generated in the electron shells of atoms. Gamma Rays are generated in the nucleus of atoms. Regardless of their energies.
U-238 is the most abundant isotope of uranium on earth. It's total decay scheme ends in Pb but we can break the whole down into smaller groups of decay chains that may or may not be included in the samples we study. An easy example is the Radium decay chain. Radium has been separated from raw Uranium ore for a long time now. Even longer, the U-238/U-235 decay chain has been separated from rocks by mankind, the most obvious practical use being for making pretty colored pottery glaze (not just red either- different oxide states can make ivory and black). This kind of separation is chemical and the processes can easily differentiate Uranium from Lead daughters for example. Simple separation cannot tell U-234, U-235 and U-238 from one another, so in all chemical types of processes the preexisting mixture of isotopes remain in the same ratio.
In the study of Trinitite we know a few things about the Uranium that was used in the Gadget, for example the tamper was made of natural uranium metal, so it had a normal complement of U-235. Some scientists calculate that 30% of the total yield came from U-235 fission, so we can expect the natural radio to be altered. in the remains.
If we had a perfect sample of depleted uranium to test, it would have started with pure U-238 and the decay chain would be simple:
As illustrated, the U-238 is present in the greatest numbers in the sample, but daughter products immediately begin to build up. First U-238 decays to Thorium-234 by Alpha Decay. Let's examine this first decay in detail.
A particular atom of U-238 decays by expelling an Alpha Particle at great speed. The nucleus of that? atom has instantly lost 2 positive particles and 2 neutral particles. At that instant the Alpha Particle takes off in some direction, and because it is going so fast, the remaining nucleus goes off in the other direction, the speed of which travel if in a vacuum would be a simple ratio of the mass of the two components (4 and 234). Sometimes this motion is probably fast enough to expel some outer electrons from the remaining atom, which at this time is already a Thorium-234 atom.
Now lets discussed this newly created Th-234 atom. It's pretty much the same as all the other Th-234 atoms but not identical because it must rearrange it's nucleus and electron shell before it can be a proper daughter. While doing this, it spits out unneeded energy to stabilize the nucleus (we call some of that energy Gamma Rays) which must of course interact with the electron shell area as it exits the atom and tries to find it's way to our Geiger Counters. Of these interaction with the electron shells, a certain number of them will generate a displaced electron, which of course must be replaced, leading to what we know as and XRF X-Ray, which we also want to find our sensor array for identification purposes.
Many other interactions happen during this process but we don't need to consider them in this discussion.
The take-away is the a U-238 DECAY makes a specific X-Ray come about from it's daughter. The XRF energy is NOT of a Uranium atom, but it's Daughter atom. Contrast this to the actual Uranium XRF X-Ray that is elicited by external excitement of? U, which is the actual Uranium XRF- these are two different and very distinct energies.
So it's clear to look for U-238 we have to look for Th-234 and Pa-234 Gamma Rays and especially XRF X-Rays.
There is one more Uranium atom to come out of this U-238 decay in fairly short order, the U-234. Notice the extremely long half-life T/2 of U-234. It is actually the head of a distinct decay chain but for that chain to reach equilibrium again, it will require centuries to go by. What's important to realize is that this is the ONLY Uranium being created in this Decay Chain, therefore the ONLY place a true Uranium XRF photon can be generated.
On the other hand, Many Plutonium isotopes decay into Uranium! The one of most interest in Trinitite is Pu-239 which decays into U-235.
My hypothesis is if we can PROVE U-XRF and can't prove any other logical reason (Th and Pa XRF) for it to be so predominant in every Trinitite sample, it might well be an indication of the presence of, and by analysis the quantity of Plutonium atoms.
A closer look at a Gamma RaySpectrum scan of Red Trinitite? (see pics in first post of this thread).
The picture and .mca attached are of a previous (19FED2020) scan of Red Trinitite
In the photo you are seeing an automatic peak search identifying the lowest major X-Ray as being 13.6? which is of course the La1 line of Uranium. Many other scans using higher energy? probes don't indicate the presence of significant, especially the first few daughters in the various U isotope's decay chains (U-234, U-235, U238)
Hundreds, even thousands of Trinitite Gamma Scans show the 3 X-Ray peaks, universally identified as U-X-Rays or U-Pb X-Rays or even Am-241 X-Rays. They are indeed U X-Rays, all 3 are there- U- La1, Lb1, Ly1.? It is my goal to prove them to be from the decay of Pu to Uranium, especially Pu-239>U-235.
It
looked like a 1024 conversion gain. Most Si detectors will use 2048 even at the
expense of counting time. Count time, FWHM, and noise can be traded off using peaking
time…its always something.
Dude,
I did the energy cal here when I built it. Used test sources.
?
Geo
?
?
?
From:
"DFEMER"
<dfemer@...> To: [email protected] Sent: Monday, September 28, 2020 12:42:20 PM Subject: Re: [XRF] Si pin xrf ..1st go
?
Nice
clean spectra, lookin’ good.?
You
can take the conversion gain up to 2048 channels which will get a bit more
resolution at the expense of a longer count time.
If
you are talking about a peak please put the cursor on it so we can read the
energy and counts. This program really needs to have the x-axis numbers to be
below the spectra as it’s really hard to see the energy which is covered up by
the spectra baseline noise.
Also
post the.mca files along with the photos so some of us can play with the data.
I’m
surprised we don’t see a large Am peak.? How do you do the energy cal?
Using 6 Am241 /ludlum??lead disc??glued to cardboard box
Si pin??near orifice
Due to the shape of
detector and fear of samples potentially damaging Be window,I opted for this
way
Anyway it is only a
prototype.
Accidentally glued one the
Am buttons upside down and it is really stuck
Will fix it next time..
Samples as follows?
1 Selenium
Was discussed in the old
forum
My sample is a centrifuged
suspension of selenium sulphide(selsen) in a??plastic sample container
.It has remained the same since preparation about 2 years ago
It sticks like a coating so
without a container,alpha is active.
?
2 X ray apron polymer
Nowadays they are lead free
and consist of polymers mixed??with antimony,tungsten or
bismuth etc to make it light weight?
I always thought there was
antimony present in my sample from my previous xrf experiments.It appears to
Tin here??
Some mass spectrometer test of Trinitite et. al? results are out there on the internet, will gather a few and see if they are showing parent, decay and fission products among the findings.
----- Original Message ----- From: Dude <dfemer@...> To: [email protected] Sent: Mon, 28 Sep 2020 16:01:16 -0400 (EDT) Subject: Re: [XRF] Si pin xrf ..1st go
LOD depends on the element but in general the XRF limit of detection at best is 0.5 ppm and above, so for a ppb range element you’ll need to do ICP/MS. That can also get stable element isotopic ratios of end member decays for forensics.
Dud, with the XRF gun, what is the likelihood of detecting a unique element in a large Trinitite sample, when the element dispersed and total weight is 1x10e-9 grams? Say the sample was 28 grams.
?
Geo
?
From: "DFEMER" <dfemer@...> To: [email protected] Sent: Monday, September 28, 2020 1:25:20 PM Subject: Re: [XRF] Si pin xrf ..1st go
?
The same scale expansion can be done selecting the Select View box on the tool bar. The cursor changes to a + and by holding the left mouse button you can select the range to expand. Click the? < > button and it expands back to full scale. Unclick the Selec View Box to get back to the Arrow pointer for selecting peak readouts
Your sensor box and RAPCAP (AmX6 ring) are in good geometry. The case of the GEO-1-2-3 is also a heat sink so make sure there is airflow around it.No blower needed, just natural air. The case gets warm like a puppy, not hot.
?
?
?
Try this-The 1-2-3 does not have to be connected or turned on for this:
?
On your selenium scan-
?
?
Bring up the saved .mca file by using
FILE; OPEN FILE function. If no other files are loaded, it will appear as Live_Data2.
?
?
Press F6 to show SPECTRA LIST drop down (if it is not on the screen already).
Click on? title Live_Data2, there will be a drop down menu, one of the options is MODIFY- select that. Within the page that comes up, you can rename the scan, maybe Se-1_Septxx2020
?
?
?
?
When that's done ,select the selenium scan, and change one setting on that- in the RANGE boxes at the bottom change the first box from 0 to 3 and the second one change from 133 to 62.
?
This will eliminate the noise at the bottom (far left) and spread out the data more and give much more detail on the screen. This is the main useful range of Si-PIN sensors. I include 62 in all my scans to preserve 59.5 as a calibration point.
?
Later you will want to examine even smaller groups of? peaks, so you can then change the RANGE boxes to say maybe 2 and 25 or whatever range contains the details you want to investigate at that moment.
?
?
By the way for all members using this same device, my recent posts on Trinitite were made with one, notice some scans are from January-February 2020 and some are from Sept2020. These are all made with same sensor s/n and still use same calibration factors after being turned off for 6+ month! No drift.?
?
have fun
Geo
From: "taray singh via groups.io" <sukhjez@...> To: [email protected] Sent: Monday, September 28, 2020 6:00:07 AM Subject: [XRF] Si pin xrf ..1st go
?
Hi guys
Using 6 Am241 /ludlum??lead disc??glued to cardboard box
Si pin??near orifice
Due to the shape of detector and fear of samples potentially damaging Be window,I opted for this way
Anyway it is only a prototype.
Accidentally glued one the Am buttons upside down and it is really stuck
Will fix it next time..
Samples as follows?
1 Selenium
Was discussed in the old forum
My sample is a centrifuged suspension of selenium sulphide(selsen) in a??plastic sample container .It has remained the same since preparation about 2 years ago
It sticks like a coating so without a container,alpha is active.
?
2 X ray apron polymer
Nowadays they are lead free and consist of polymers mixed??with antimony,tungsten or bismuth etc to make it light weight?
I always thought there was antimony present in my sample from my previous xrf experiments.It appears to Tin here??
LOD
depends on the element but in general the XRF limit of detection at best is 0.5
ppm and above, so for a ppb range element you’ll need to do ICP/MS. That can
also get stable element isotopic ratios of end member decays for forensics.
Dud,
with the XRF gun, what is the likelihood of detecting a unique element in a
large Trinitite sample, when the element dispersed and total weight is 1x10e-9
grams? Say the sample was 28 grams.
?
Geo
?
From:
"DFEMER"
<dfemer@...> To: [email protected] Sent: Monday, September 28, 2020 1:25:20 PM Subject: Re: [XRF] Si pin xrf ..1st go
?
The
same scale expansion can be done selecting the Select View box on the tool bar.
The cursor changes to a + and by holding the left mouse button you can select
the range to expand. Click the? < > button and it expands back to
full scale. Unclick the Selec View Box to get back to the Arrow pointer for
selecting peak readouts
Your
sensor box and RAPCAP (AmX6 ring) are in good geometry. The case of the
GEO-1-2-3 is also a heat sink so make sure there is airflow around it.No blower
needed, just natural air. The case gets warm like a puppy, not hot.
?
?
?
Try
this-The 1-2-3 does not have to be connected or turned on for this:
?
On
your selenium scan-
?
?
Bring
up the saved .mca file by using
FILE;
OPEN FILE function. If no other files are loaded, it will appear as Live_Data2.
?
?
Press
F6 to show SPECTRA LIST drop down (if it is not on the screen already).
Click
on? title Live_Data2, there will be a drop down menu, one of the options
is MODIFY- select that. Within the page that comes up, you can rename the scan,
maybe Se-1_Septxx2020
?
?
?
?
When
that's done ,select the selenium scan, and change one setting on that- in the RANGE
boxes at the bottom change the first box from 0 to 3 and the second one change
from 133 to 62.
?
This
will eliminate the noise at the bottom (far left) and spread out the data more
and give much more detail on the screen. This is the main useful range of
Si-PIN sensors. I include 62 in all my scans to preserve 59.5 as a calibration
point.
?
Later
you will want to examine even smaller groups of? peaks, so you can then
change the RANGE boxes to say maybe 2 and 25 or whatever range contains the details
you want to investigate at that moment.
?
?
By
the way for all members using this same device, my recent posts on Trinitite
were made with one, notice some scans are from January-February 2020 and some
are from Sept2020. These are all made with same sensor s/n and still use same
calibration factors after being turned off for 6+ month! No drift.?
?
have
fun
Geo
From:
"taray
singh via groups.io" <sukhjez@...> To: [email protected] Sent: Monday, September 28, 2020 6:00:07 AM Subject: [XRF] Si pin xrf ..1st go
?
Hi guys
Using 6 Am241 /ludlum??lead disc??glued to cardboard box
Si pin??near orifice
Due to the shape of detector and fear of samples potentially
damaging Be window,I opted for this way
Anyway it is only a prototype.
Accidentally glued one the Am buttons upside down and it is really
stuck
Will fix it next time..
Samples as follows?
1 Selenium
Was discussed in the old forum
My sample is a centrifuged suspension of selenium sulphide(selsen)
in a??plastic sample container .It has remained the same since preparation
about 2 years ago
It sticks like a coating so without a container,alpha is active.
?
2 X ray apron polymer
Nowadays they are lead free and consist of polymers mixed??with antimony,tungsten or bismuth
etc to make it light weight?
I always thought there was antimony present in my sample from my
previous xrf experiments.It appears to Tin here??
Another bummer. Been trying to load DECAY_v4 since last night. No go. Install program insists the program be loaded to PROGRAM FILES, but WIN10 wont let me mess with that folder, even tho logged in as administrator. Had same issues when first loaded WIN 10 into all the notebooks.
Pictured attached this post is from Pu-238_? pdf in FILES, shows all the different L X-Rays. When added together the sum is approx. what DECAYv3 says. But we know the energies are slightly different than the one listed in V3.
Thanks for Decay4.zip, will load that into a folder other than PROGRAM FILES, to see will it run from there. That's how we had to do V3 too. Perhaps I need V3 removed?
Also perhaps we could swap out the relative tables in V3 with V4 tables?
Another bummer. Been trying to load DECAY_v4 since last
night. No go. Install program insists the program be loaded to PROGRAM FILES,
but WIN10 wont let me mess with that folder, even tho logged in as
administrator. Had same issues when first loaded WIN 10 into all the notebooks.
Pictured attached this post is from Pu-238_? pdf in FILES, shows all the
different L X-Rays. When added together the sum is approx. what DECAYv3 says.
But we know the energies are slightly different than the one listed in V3.
Thanks for Decay4.zip, will load that into a folder other than PROGRAM FILES,
to see will it run from there. That's how we had to do V3 too. Perhaps I need
V3 removed?
Also perhaps we could swap out the relative tables in V3 with V4 tables?
Dud, with the XRF gun, what is the likelihood of detecting a unique element in a large Trinitite sample, when the element dispersed and total weight is 1x10e-9 grams? Say the sample was 28 grams.
From: "DFEMER" <dfemer@...> To: [email protected] Sent: Monday, September 28, 2020 1:25:20 PM Subject: Re: [XRF] Si pin xrf ..1st go
The
same scale expansion can be done selecting the Select View box on the tool bar.
The cursor changes to a + and by holding the left mouse button you can select
the range to expand. Click the? < > button and it expands back to full
scale. Unclick the Selec View Box to get back to the Arrow pointer for
selecting peak readouts
Your
sensor box and RAPCAP (AmX6 ring) are in good geometry. The case of the
GEO-1-2-3 is also a heat sink so make sure there is airflow around it.No blower
needed, just natural air. The case gets warm like a puppy, not hot.
?
?
?
Try
this-The 1-2-3 does not have to be connected or turned on for this:
?
On
your selenium scan-
?
?
Bring
up the saved .mca file by using
FILE;
OPEN FILE function. If no other files are loaded, it will appear as Live_Data2.
?
?
Press
F6 to show SPECTRA LIST drop down (if it is not on the screen already).
Click
on? title Live_Data2, there will be a drop down menu, one of the options
is MODIFY- select that. Within the page that comes up, you can rename the scan,
maybe Se-1_Septxx2020
?
?
?
?
When
that's done ,select the selenium scan, and change one setting on that- in the
RANGE boxes at the bottom change the first box from 0 to 3 and the second one
change from 133 to 62.
?
This
will eliminate the noise at the bottom (far left) and spread out the data more
and give much more detail on the screen. This is the main useful range of
Si-PIN sensors. I include 62 in all my scans to preserve 59.5 as a calibration
point.
?
Later
you will want to examine even smaller groups of? peaks, so you can then
change the RANGE boxes to say maybe 2 and 25 or whatever range contains the
details you want to investigate at that moment.
?
?
By
the way for all members using this same device, my recent posts on Trinitite
were made with one, notice some scans are from January-February 2020 and some
are from Sept2020. These are all made with same sensor s/n and still use same
calibration factors after being turned off for 6+ month! No drift.?
?
have
fun
Geo
From:
"taray
singh via groups.io" <sukhjez@...> To: [email protected] Sent: Monday, September 28, 2020 6:00:07 AM Subject: [XRF] Si pin xrf ..1st go
?
Hi guys
Using 6 Am241 /ludlum??lead disc??glued to cardboard box
Si pin??near orifice
Due to the shape of detector and fear of samples potentially
damaging Be window,I opted for this way
Anyway it is only a prototype.
Accidentally glued one the Am buttons upside down and it is really
stuck
Will fix it next time..
Samples as follows?
1 Selenium
Was discussed in the old forum
My sample is a centrifuged suspension of selenium sulphide(selsen)
in a??plastic sample container .It has remained the same since
preparation about 2 years ago
It sticks like a coating so without a container,alpha is active.
?
2 X ray apron polymer
Nowadays they are lead free and consist of polymers mixed??with antimony,tungsten or bismuth
etc to make it light weight?
I always thought there was antimony present in my sample from my
previous xrf experiments.It appears to Tin here??
The
same scale expansion can be done selecting the Select View box on the tool bar.
The cursor changes to a + and by holding the left mouse button you can select
the range to expand. Click the? < > button and it expands back to full
scale. Unclick the Selec View Box to get back to the Arrow pointer for
selecting peak readouts
Your
sensor box and RAPCAP (AmX6 ring) are in good geometry. The case of the
GEO-1-2-3 is also a heat sink so make sure there is airflow around it.No blower
needed, just natural air. The case gets warm like a puppy, not hot.
?
?
?
Try
this-The 1-2-3 does not have to be connected or turned on for this:
?
On
your selenium scan-
?
?
Bring
up the saved .mca file by using
FILE;
OPEN FILE function. If no other files are loaded, it will appear as Live_Data2.
?
?
Press
F6 to show SPECTRA LIST drop down (if it is not on the screen already).
Click
on? title Live_Data2, there will be a drop down menu, one of the options
is MODIFY- select that. Within the page that comes up, you can rename the scan,
maybe Se-1_Septxx2020
?
?
?
?
When
that's done ,select the selenium scan, and change one setting on that- in the
RANGE boxes at the bottom change the first box from 0 to 3 and the second one
change from 133 to 62.
?
This
will eliminate the noise at the bottom (far left) and spread out the data more
and give much more detail on the screen. This is the main useful range of
Si-PIN sensors. I include 62 in all my scans to preserve 59.5 as a calibration
point.
?
Later
you will want to examine even smaller groups of? peaks, so you can then
change the RANGE boxes to say maybe 2 and 25 or whatever range contains the
details you want to investigate at that moment.
?
?
By
the way for all members using this same device, my recent posts on Trinitite
were made with one, notice some scans are from January-February 2020 and some
are from Sept2020. These are all made with same sensor s/n and still use same
calibration factors after being turned off for 6+ month! No drift.?
?
have
fun
Geo
From:
"taray
singh via groups.io" <sukhjez@...> To: [email protected] Sent: Monday, September 28, 2020 6:00:07 AM Subject: [XRF] Si pin xrf ..1st go
?
Hi guys
Using 6 Am241 /ludlum??lead disc??glued to cardboard box
Si pin??near orifice
Due to the shape of detector and fear of samples potentially
damaging Be window,I opted for this way
Anyway it is only a prototype.
Accidentally glued one the Am buttons upside down and it is really
stuck
Will fix it next time..
Samples as follows?
1 Selenium
Was discussed in the old forum
My sample is a centrifuged suspension of selenium sulphide(selsen)
in a??plastic sample container .It has remained the same since
preparation about 2 years ago
It sticks like a coating so without a container,alpha is active.
?
2 X ray apron polymer
Nowadays they are lead free and consist of polymers mixed??with antimony,tungsten or bismuth
etc to make it light weight?
I always thought there was antimony present in my sample from my
previous xrf experiments.It appears to Tin here??
From: "DFEMER" <dfemer@...> To: [email protected] Sent: Monday, September 28, 2020 12:42:20 PM Subject: Re: [XRF] Si pin xrf ..1st go
Nice
clean spectra, lookin’ good.?
You
can take the conversion gain up to 2048 channels which will get a bit more
resolution at the expense of a longer count time.
If
you are talking about a peak please put the cursor on it so we can read the
energy and counts. This program really needs to have the x-axis numbers to be
below the spectra as it’s really hard to see the energy which is covered up by
the spectra baseline noise.
Also
post the.mca files along with the photos so some of us can play with the data.
I’m
surprised we don’t see a large Am peak.? How do you do the energy cal?
Using 6 Am241 /ludlum??lead disc??glued to cardboard box
Si pin??near orifice
Due to the shape of detector and fear of samples potentially
damaging Be window,I opted for this way
Anyway it is only a prototype.
Accidentally glued one the Am buttons upside down and it is really
stuck
Will fix it next time..
Samples as follows?
1 Selenium
Was discussed in the old forum
My sample is a centrifuged suspension of selenium sulphide(selsen)
in a??plastic sample container .It has remained
the same since preparation about 2 years ago
It sticks like a coating so without a container,alpha is active.
?
2 X ray apron polymer
Nowadays they are lead free and consist of polymers mixed??with antimony,tungsten or
bismuth etc to make it light weight?
I always thought there was antimony present in my sample from my
previous xrf experiments.It appears to Tin here??
You
can take the conversion gain up to 2048 channels which will get a bit more
resolution at the expense of a longer count time.
If
you are talking about a peak please put the cursor on it so we can read the
energy and counts. This program really needs to have the x-axis numbers to be
below the spectra as it’s really hard to see the energy which is covered up by
the spectra baseline noise.
Also
post the.mca files along with the photos so some of us can play with the data.
I’m
surprised we don’t see a large Am peak.? How do you do the energy cal?
Using 6 Am241 /ludlum??lead disc??glued to cardboard box
Si pin??near orifice
Due to the shape of detector and fear of samples potentially
damaging Be window,I opted for this way
Anyway it is only a prototype.
Accidentally glued one the Am buttons upside down and it is really
stuck
Will fix it next time..
Samples as follows?
1 Selenium
Was discussed in the old forum
My sample is a centrifuged suspension of selenium sulphide(selsen)
in a??plastic sample container .It has remained
the same since preparation about 2 years ago
It sticks like a coating so without a container,alpha is active.
?
2 X ray apron polymer
Nowadays they are lead free and consist of polymers mixed??with antimony,tungsten or
bismuth etc to make it light weight?
I always thought there was antimony present in my sample from my
previous xrf experiments.It appears to Tin here??
