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 If a piece of information is incorrect, a link outdated, or the presentation choppy or unclear, the user can just click "Edit Page" at the bottom and then fix the mistake.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?]
----- Original Message ----- From: Mike L. <loughlin3@...> To: [email protected] Sent: Wed, 14 Oct 2020 07:06:58 -0400 (EDT) Subject: Re: [XRF] Trinitite Sub Topic 1 Where's the Uranium?
On Tue, Oct 13, 2020 at 07:38 PM, <GEOelectronics@...> wrote:
----- Original Message ----- From: Dude <dfemer@...> To: [email protected] Sent: Tue, 13 Oct 2020 19:55:01 -0400 (EDT) Subject: Re: [XRF] Trinitite Sub Topic 1 Where's the Uranium?
Geo,
I wouldn¡¯t call the 1.001MeV Pa234m gamma prominent by any respects as it has a yield of only 0.8% while the Th-234 gamma yield is 4.8%.? The Th-234 will have a lower limit of detection for a given weight of material due to its higher yield. Now if the U-238 is shielded by soil or other factors then the Pa234m 1.001 line would be a better choice to look at.
First up is an excerpt from the best HPGe scan of Trinitite I could find, done by Jon Rosenstiel for the Pittauerova/Kolb et al paper attached.
If U-238 is responsible for the U L X-Rays by the decay down to U-234, then where are the other signs? of that short decay chain? We should see Th and Pa X-Rays and a very prominent 1001keV Gamma Ray from same U-234 being created by Pa-234m decay:
<br><br>----- Original Message -----<br>From: GEOelectronics@...<br>To: [email protected]<br>Sent: Tue, 13 Oct 2020 20:14:37 -0400 (EDT)<br>Subject: Re: [XRF] Trinitite Sub Topic 1 Where's the Uranium?<br><br><html><head><style>/*<![CDATA[*/body {<br> height: 100.0%;<br> color: rgb(0,0,0);<br> font-size: 12.0pt;<br> font-family: arial , helvetica , sans-serif;<br>}<br>/*]]>*/</style></head><body><div>Good point Dudley- they are also not in evidence.</div><div><br /></div><div><div>Th-234</div><div>Gamma Emissions:</div><div>Intensity Energy Decay <br />(%)? ? ? ? ? (keV) Mode</div><div>4.8000? ? ? 63.29 b-<br />2.8100? ? ? 92.38 b-<br />2.7700? ? ? 92.80 b-<br /></div></div><div><br /></div><div>----- Original Message -----<br />From: Dude <dfemer@cox.net><br />To: XRF@groups.io<br />Sent: Tue, 13 Oct 2020 19:55:01 -0400 (EDT)<br />Subject: Re: [XRF] Trinitite Sub Topic 1 Where's the Uranium?<br /></div><div><br /></div><div><style>/*<![CDATA[*/p.MsoNormal, li.MsoNormal, div.MsoNormal {<br>}<br>/*]]>*/</style></div><div class="Section1"><p class="MsoNormal"><span style="font-family:'arial' , 'sans-serif';color:black">Geo,</span></p><p class="MsoNormal"><span style="font-family:'arial' , 'sans-serif';color:black">I<br />wouldn¡¯t call the 1.001MeV Pa234m gamma prominent by any respects as it has a yield<br />of only 0.8% while the Th-234 gamma yield is 4.8%.? The Th-234 will have a<br />lower limit of detection for a given weight of material due to its higher yield.<br />Now if the U-238 is shielded by soil or other factors then the Pa234m 1.001 line<br />would be a better choice to look at.</span></p><p class="MsoNormal"><span style="font-family:'arial' , 'sans-serif';color:black">Dud<br /></span></p><p class="MsoNormal"><span style="font-family:'arial' , 'sans-serif';color:black">?</span></p><div><div style="border:none;border-top:solid #b5c4df 1pt;padding:3pt 0in 0in 0in"><p class="MsoNormal"><b><span style="font-size:10pt;font-family:'tahoma' , 'sans-serif'">From:</span></b><span style="font-size:10pt;font-family:'tahoma' , 'sans-serif'"> XRF@groups.io<br />[mailto:XRF@groups.io] <b>On Behalf Of </b>GEOelectronics@rallstech.net<br /><b>Sent:</b> Tuesday, October 13, 2020 3:53 PM<br /><b>To:</b> XRF@groups.io<br /><b>Subject:</b> [XRF] Trinitite Sub Topic 1 Where's the Uranium?</span></p></div></div><p class="MsoNormal">?</p><p class="MsoNormal">Let's hash this out in a separate sub-topic<br /><br /><br />First up is an excerpt from the best HPGe scan of Trinitite I could find, done<br />by Jon Rosenstiel for the Pittauerova/Kolb et al paper attached.<br /><br /><img id="_x0000_i1025" src="cid:image001.png@01D6A17F.C5167470" alt="Trinitie-HIGH-AND-LOW-J-Rosentiel-1.png" data-mce-src="cid:image001.png@01D6A17F.C5167470" /><br /><br /><br /><br /><br />If U-238 is responsible for the U L X-Rays by the decay down to U-234, then<br />where are the other signs? of that short decay chain? We should see Th and<br />Pa X-Rays and a very prominent 1001keV Gamma Ray from same U-234 being created<br />by Pa-234m decay:<br /><br /><br /><br /><img id="_x0000_i1026" src="cid:image002.png@01D6A17F.C5167470" alt="U-238_Decay_and_Progeny_X-Rays.png" data-mce-src="cid:image002.png@01D6A17F.C5167470" /><br /><br /><br />Geo</p><div><p class="MsoNormal"><br /></p><br /></div></div><div><br /></div><div><br /></div><div><br /></div></body></html><div style="color:white"></div> <br><br><br>
----- Original Message ----- From: Dude <dfemer@...> To: [email protected] Sent: Tue, 13 Oct 2020 19:55:01 -0400 (EDT) Subject: Re: [XRF] Trinitite Sub Topic 1 Where's the Uranium?
Geo,
I wouldn¡¯t call the 1.001MeV Pa234m gamma prominent by any respects as it has a yield of only 0.8% while the Th-234 gamma yield is 4.8%.? The Th-234 will have a lower limit of detection for a given weight of material due to its higher yield. Now if the U-238 is shielded by soil or other factors then the Pa234m 1.001 line would be a better choice to look at.
First up is an excerpt from the best HPGe scan of Trinitite I could find, done by Jon Rosenstiel for the Pittauerova/Kolb et al paper attached.
If U-238 is responsible for the U L X-Rays by the decay down to U-234, then where are the other signs? of that short decay chain? We should see Th and Pa X-Rays and a very prominent 1001keV Gamma Ray from same U-234 being created by Pa-234m decay:
I
wouldn¡¯t call the 1.001MeV Pa234m gamma prominent by any respects as it has a yield
of only 0.8% while the Th-234 gamma yield is 4.8%.? The Th-234 will have a
lower limit of detection for a given weight of material due to its higher yield.
Now if the U-238 is shielded by soil or other factors then the Pa234m 1.001 line
would be a better choice to look at.
First up is an excerpt from the best HPGe scan of Trinitite I could find, done
by Jon Rosenstiel for the Pittauerova/Kolb et al paper attached.
If U-238 is responsible for the U L X-Rays by the decay down to U-234, then
where are the other signs? of that short decay chain? We should see Th and
Pa X-Rays and a very prominent 1001keV Gamma Ray from same U-234 being created
by Pa-234m decay:
First up is an excerpt from the best HPGe scan of Trinitite I could find, done by Jon Rosenstiel for the Pittauerova/Kolb et al paper attached.
If U-238 is responsible for the U L X-Rays by the decay down to U-234, then where are the other signs? of that short decay chain? We should see Th and Pa X-Rays and a very prominent 1001keV Gamma Ray from same U-234 being created by Pa-234m decay:
Ok
that explains what I was confused about. I thought we were talking about the Fe
loaded Trinitite. That also addressed the problem of source vs self XRF of the Fe
samples.
How
do you do a background subtraction, energy cal, and Region Of Interest in Theremino?
Does it give net or integral areas, centroids, FWHM, uncertainties, change a data
base, do peak ID, calculate activity¡etc. ?If it¡¯s not linear you fit it to a
polynomial. Does the linearization slider tell you error of fit? How do you
know its correct at all energies. Energy cals use known energy cal sources from
a low to high energy and then do a linear or polynomial fit which ever gives
the best fit. Can Theremino even do that?
LOD
is Limit of Detection the point at which statistically you can¡¯t say for certain
it¡¯s there.? i.e. is 4 counts noise or signal in a 2 count background.
There
are no calibrations in your MCA files, you need a cal file in there to see what
you¡¯re looking at or you¡¯re just guessing at peaks which will get you in big
trouble with unknowns or the unexpected, especially with the close interference
energies in XRF. Gathering the spectra in Dpp and moving it over to a program that
was never intended for this kind of work to calibrate it is exceedingly poor practice.
We all go through the ¡°but it¡¯s what I grew up with and know¡± but there is a time
to move up to the next step where things are done differently and in a
professional and proper manner.
You¡¯re
one of the better problem thinkers and solvers here you should match that with proper
software.
Dud,? There is nothing special about Trinitite #1.?
It is just a piece I own.? Charles Young knew I was doing a multi-day
Trinitite X-Ray Spectrum w/o excitation.? He said GEO was looking for one
so that is why I parachuted into this thread.? Attached is the last, best
spectrum I did of Trintite #1 and a NaI spectrum of it.?
GEO then wanted a Am241 button spectrum for comparison, so I gave that a
try.? I didn't post this MCA because I knew it was not what he was looking
for, but I wanted something to look at for further direction.
I look forward to learning the DPPmca software, but Theremino is OK.? The GEO
1-2-3 SiPin is so beautifully linear, all the Theremino features you are
complaining about are turned off.? These same features do a good job
of? linearizing NaI probes below 100 keV and sometimes the superposition
of spectrums is very informative.
----- Original Message ----- From: Mike L. <loughlin3@...> To: [email protected] Sent: Tue, 13 Oct 2020 16:08:46 -0400 (EDT) Subject: Re: [XRF] Trinitite
On Mon, Oct 12, 2020 at 09:16 PM, <GEOelectronics@...> wrote:
To test the effect, try to measure your Am internally excited XRF X-Rays vs its Np daughter self XRF X-Rays - this will give a hint as to the efficiency of? internal XRF.
Yes,? I have always been impressed with the relative strength of "internally excited XRF X-rays".? My first realization of what they were was with the Bi/Pb x-rays in the Ra226 spectrum (NaI), in which they are always very prominent.? ?
I was at first confused by your description of? "internally excited XRF X-rays".? In Dr. Gilmore's usage these are "X-rays associated with nuclides".? Florescence comes from energy arriving from outside the atom, whether XRF or self-florescence.? I am not saying your usage is wrong, just not what I am used to.? I think I like Dud's "decay X-Ray" best.
Yes Dr. Gilmore also held that the external excitation be X-Rays, which is incorrect.
"To fluoresce by the application of X-Rays" is too narrow a description. Otherwise I learned a great deal from our discussions with Dr. Gilmore on the old Yahoo group.
Encyclopedia Britannica defines it: "Fluorescence, emission of?, usually visible?, caused by??of??in a material,"? which is also either incorrect or narrow minded. The term visible light should be dropped.?
Inner electron transitions = X-Rays, outer orbitals are visible light. The term electromagnetic radiation or photon is correct for both.
Inner orbitals don't pay any attention to what is going on in the valence shells.
----- Original Message ----- From: Mike L. <loughlin3@...> To: [email protected] Sent: Tue, 13 Oct 2020 16:08:46 -0400 (EDT) Subject: Re: [XRF] Trinitite
On Mon, Oct 12, 2020 at 09:16 PM, <GEOelectronics@...> wrote:
To test the effect, try to measure your Am internally excited XRF X-Rays vs its Np daughter self XRF X-Rays - this will give a hint as to the efficiency of? internal XRF.
Yes,? I have always been impressed with the relative strength of "internally excited XRF X-rays".? My first realization of what they were was with the Bi/Pb x-rays in the Ra226 spectrum (NaI), in which they are always very prominent.? ?
I was at first confused by your description of? "internally excited XRF X-rays".? In Dr. Gilmore's usage these are "X-rays associated with nuclides".? Florescence comes from energy arriving from outside the atom, whether XRF or self-florescence.? I am not saying your usage is wrong, just not what I am used to.? I think I like Dud's "decay X-Ray" best.
On Mon, Oct 12, 2020 at 09:16 PM, <GEOelectronics@...> wrote:
To test the effect, try to measure your Am internally excited XRF X-Rays vs its Np daughter self XRF X-Rays - this will give a hint as to the efficiency of? internal XRF.
Yes,? I have always been impressed with the relative strength of "internally excited XRF X-rays".? My first realization of what they were was with the Bi/Pb x-rays in the Ra226 spectrum (NaI), in which they are always very prominent.? ?
I was at first confused by your description of? "internally excited XRF X-rays".? In Dr. Gilmore's usage these are "X-rays associated with nuclides".? Florescence comes from energy arriving from outside the atom, whether XRF or self-florescence.? I am not saying your usage is wrong, just not what I am used to.? I think I like Dud's "decay X-Ray" best.
On Tue, Oct 13, 2020 at 10:40 AM, <GEOelectronics@...> wrote:
There you will find a brief introduction to this group, and especially (message#1) the definitions we use in the XRF field, especially te definition of "X-Ray" and "Gamma-Ray" which may or may not be what you are used to.
¡°The beginning of wisdom is to call things by their proper name."? ---?Confucius
Dud,? There is nothing special about Trinitite #1.? It is just a piece I own.? Charles Young knew I was doing a multi-day Trinitite X-Ray Spectrum w/o excitation.? He said GEO was looking for one so that is why I parachuted into this thread.? Attached is the last, best spectrum I did of Trintite #1 and a NaI spectrum of it.?
GEO then wanted a Am241 button spectrum for comparison, so I gave that a try.? I didn't post this MCA because I knew it was not what he was looking for, but I wanted something to look at for further direction.
I look forward to learning the DPPmca software, but Theremino is OK.? The GEO 1-2-3 SiPin is so beautifully linear, all the Theremino features you are complaining about are turned off.? These same features do a good job of? linearizing NaI probes below 100 keV and sometimes the superposition of spectrums is very informative.
One thing I liked better on the Yahoo Group platform was the idea of threads, in which you could change the subject title but keep that message associated with the intended thread. Evidently if you try that with Groups.io, it automatically starts up a different thread..
Let me make a suggestion to anyone who wants to post to this particular thread, "Trinitite, Testing Trinitite with different methods".
1) Go back to the first messages posted to this group by the owner, and read it plus the first half-dozen or so messages following. There you will find a brief introduction to this group, and especially (message#1) the definitions we use in the XRF field, especially te definition of "X-Ray" and "Gamma-Ray" which may or may not be what you are used to. Here's a link to message #1:
From: "DFEMER" <dfemer@...> To: [email protected] Sent: Monday, October 12, 2020 11:26:45 PM Subject: Re: [XRF] Trinitite
Mike,
What
is Trinite #1? We have so many different Trinitite¡¯s runs here it¡¯s hard to
figure out which one we are looking at. Please everyone describe how and what
you¡¯re running and please put the mca file up along with the screen grab.
You¡¯re
not seeing any U x-rays with the active source due the limit of detection . A
count time of 135 sec with such a strong source has over whelmed any weak U
signal and buried it in the noise. Just eyeballing off the png the U La1 has
about 650 counts in 96 hours of counting or ?
about
0.002 counts per second, so you have only 0.2 U counts in the 136 sec counting
window.? No amount of normalizing to a peak is going to get around that fact.
Which
points out one of my many objections to using Theremino with all the fudging
factor sliders that have been included to make something look pretty but have
no real use in understanding and interpreting the data, it¡¯s a poor crutch. While
it may be ok for a good cheap entry for NaI it¡¯s not for using with a high end XRF
professional system. Stick with the DPPmca or the Spectrgryph software.
I
think you¡¯re right on the U-Xrays being from Pu as the U-238 has a specific activity
of 3.3E-7Ci/g vs 6.2 E-2 Ci/g for Pu239 and that coupled with the short in-growth
time is going to be rough to measure much less separate. It would be better to
use the Th-234 decay gamma and Pa decay x-ray to try and sort out the different
U ?X- rays but I think it will be a LOD problem all over again due to low mass
and activity.
On Sun, Oct 11, 2020 at 10:14 AM,
<GEOelectronics@...> wrote:
Charles' software is beautiful
Absolutely, the guy is a wizard!
I really like the Pu239 ID chart you attached.? Is that isotope identifier
and library part of the free AMTEK DPP software download???
So far I have only been using the DPP software to acquire the MCA file and then
processing it with Theremino.? I need to spend some time and learn the DPP
MCA software also.
I don't understand your request about a Am241 only spectrum.? There is no
clear 17.22 keV peak??(or other U x-rays) with Am241.? I
equalized at the 59.5 keV counts and the two superimposed spectrums are
attached.??
If you are trying to determine were the U x-rays are coming from in Trinitite,
I think they are almost all associated with Pu239.? Yes the NU tamper was
probably much larger than the Pu core, but if I am reading the charts
right,? the specific activity of Pu239 is something like 5 orders of
magnitude greater than U238/Pa234m.? The paper below indicates to me that
Pu239 is much more active (see figure 2 and table 2) than the U238.? Maybe
I just don't understand what you are doing.
Just for fun, I took a look at NU Fiestaware with the SiPin.? I saw a lot
of Th x-rays (associated with U238 and U235 decay?) and Pb x-rays (florescence
from the glaze?).? Surprisingly, I didn't see much in the way of U x-rays
What
is Trinite #1? We have so many different Trinitite¡¯s runs here it¡¯s hard to
figure out which one we are looking at. Please everyone describe how and what
you¡¯re running and please put the mca file up along with the screen grab.
You¡¯re
not seeing any U x-rays with the active source due the limit of detection . A
count time of 135 sec with such a strong source has over whelmed any weak U
signal and buried it in the noise. Just eyeballing off the png the U La1 has
about 650 counts in 96 hours of counting or ?
about
0.002 counts per second, so you have only 0.2 U counts in the 136 sec counting
window.? No amount of normalizing to a peak is going to get around that fact.
Which
points out one of my many objections to using Theremino with all the fudging
factor sliders that have been included to make something look pretty but have
no real use in understanding and interpreting the data, it¡¯s a poor crutch. While
it may be ok for a good cheap entry for NaI it¡¯s not for using with a high end XRF
professional system. Stick with the DPPmca or the Spectrgryph software.
I
think you¡¯re right on the U-Xrays being from Pu as the U-238 has a specific activity
of 3.3E-7Ci/g vs 6.2 E-2 Ci/g for Pu239 and that coupled with the short in-growth
time is going to be rough to measure much less separate. It would be better to
use the Th-234 decay gamma and Pa decay x-ray to try and sort out the different
U ?X- rays but I think it will be a LOD problem all over again due to low mass
and activity.
On Sun, Oct 11, 2020 at 10:14 AM,
<GEOelectronics@...> wrote:
Charles' software is beautiful
Absolutely, the guy is a wizard!
I really like the Pu239 ID chart you attached.? Is that isotope identifier
and library part of the free AMTEK DPP software download???
So far I have only been using the DPP software to acquire the MCA file and then
processing it with Theremino.? I need to spend some time and learn the DPP
MCA software also.
I don't understand your request about a Am241 only spectrum.? There is no
clear 17.22 keV peak??(or other U x-rays) with Am241.? I
equalized at the 59.5 keV counts and the two superimposed spectrums are
attached.??
If you are trying to determine were the U x-rays are coming from in Trinitite,
I think they are almost all associated with Pu239.? Yes the NU tamper was
probably much larger than the Pu core, but if I am reading the charts
right,? the specific activity of Pu239 is something like 5 orders of
magnitude greater than U238/Pa234m.? The paper below indicates to me that
Pu239 is much more active (see figure 2 and table 2) than the U238.? Maybe
I just don't understand what you are doing.
Just for fun, I took a look at NU Fiestaware with the SiPin.? I saw a lot
of Th x-rays (associated with U238 and U235 decay?) and Pb x-rays (florescence
from the glaze?).? Surprisingly, I didn't see much in the way of U x-rays
"I understand that.? I expected there might be some U x-rays because the early U238 daughter Pa234m beta decays to U234."
Correct. That is where the decay U X-Ray would come? from U-234 being created. For every alpha decay of U-238, there will later be a U-234 atom created, and there is a known statistical relationship to an L X-Ray happening or not. This is a sure bet, and the 234 is already back into secular equilibrium with the 238, but nothing below is or will be for a very long time. By the way, old FW natural uranium was chemically separated, leaving it with a full boat of U-234? and 235
in equilibrium already.? NOTE we need to measure the U-238 load by monitoring the? Th and Pa X-Rays or the 1001 keV Gamma Rays.
There is a? chance of an alphas particle causing actual XRF of a uranium atom also exists as you say.
To test the effect, try to measure your Am internally excited XRF X-Rays vs its Np daughter self XRF X-Rays - this will give a hint as to the efficiency of? internal XRF. Don't forget, during decay the charge or energy must pass through the electron shells of the atom, while once free may not encounter another atom that intimately again.
Lots of fun stuff to try still.
It's a physical sequence
1=? A particle (Alpha or Beta) leaves parent nucleus -at this point it becomes daughter?nucleus
1.1= nucleus kicks back due to action/reaction in proportion to its mass vs the particle mass and speed.
----- Original Message ----- From: Mike L. <loughlin3@...> To: [email protected] Sent: Mon, 12 Oct 2020 21:20:36 -0400 (EDT) Subject: Re: [XRF] Trinitite
On Mon, Oct 12, 2020 at 07:25 PM, <GEOelectronics@...> wrote:
Uranium decaying does not bring on U X-Rays, only uranium being created by decay does that. U
I understand that.? I expected there might be some U x-rays because the early U238 daughter Pa234m beta decays to U234.? I also thought there might be some self florescence of the U (like there is of Pb), because of the high % of U in the glaze.? Is this wrong?? ?I think I see some tiny indications of U x-rays in the FW spectrum, but they are dwarfed by by the Th and Pb peaks.
"The alpha/ Gamma/ X-Ray emissions happen in sequence 1-2-3."
On Mon, Oct 12, 2020 at 07:25 PM, <GEOelectronics@...> wrote:
Uranium decaying does not bring on U X-Rays, only uranium being created by decay does that. U
I understand that.? I expected there might be some U x-rays because the early U238 daughter Pa234m beta decays to U234.? I also thought there might be some self florescence of the U (like there is of Pb), because of the high % of U in the glaze.? Is this wrong?? ?I think I see some tiny indications of U x-rays in the FW spectrum, but they are dwarfed by by the Th and Pb peaks.
"The alpha/ Gamma/ X-Ray emissions happen in sequence 1-2-3."
On the Am, as well as the U, it's the daughter's X-Rays we see.? Am decays by alpha particle emission to Np-237, the X-Rays and gamma rays come from the Np atom and are part of the normal decay process of the new nucleus giving off extra energy (59.5) and that energy crossing the electron shells, which sometimes causes one of the electrons to gain energy and leave it's orbit. When another electron (from another orbit) fills the missing space, the electromagnetic X-Ray energy being the difference between kinetic energy of the two orbital spaces.
Uranium decaying does not bring on U X-Rays, only uranium being created by decay does that. Uranium decaying gives rise to X-Rays of the daughter element, whatever that may be.
The alpha/ Gamma/ X-Ray emissions happen in sequence 1-2-3.
----- Original Message ----- From: Mike L. <loughlin3@...> To: [email protected] Sent: Mon, 12 Oct 2020 19:41:05 -0400 (EDT) Subject: Re: [XRF] Trinitite
On Sun, Oct 11, 2020 at 10:14 AM, <GEOelectronics@...> wrote:
Charles' software is beautiful
Absolutely, the guy is a wizard!
I really like the Pu239 ID chart you attached.? Is that isotope identifier and library part of the free AMTEK DPP software download??? So far I have only been using the DPP software to acquire the MCA file and then processing it with Theremino.? I need to spend some time and learn the DPP MCA software also.
I don't understand your request about a Am241 only spectrum.? There is no clear 17.22 keV peak??(or other U x-rays) with Am241.? I equalized at the 59.5 keV counts and the two superimposed spectrums are attached.??
If you are trying to determine were the U x-rays are coming from in Trinitite, I think they are almost all associated with Pu239.? Yes the NU tamper was probably much larger than the Pu core, but if I am reading the charts right,? the specific activity of Pu239 is something like 5 orders of magnitude greater than U238/Pa234m.? The paper below indicates to me that Pu239 is much more active (see figure 2 and table 2) than the U238.? Maybe I just don't understand what you are doing.
Just for fun, I took a look at NU Fiestaware with the SiPin.? I saw a lot of Th x-rays (associated with U238 and U235 decay?) and Pb x-rays (florescence from the glaze?).? Surprisingly, I didn't see much in the way of U x-rays
On Sun, Oct 11, 2020 at 10:14 AM, <GEOelectronics@...> wrote:
Charles' software is beautiful
Absolutely, the guy is a wizard!
I really like the Pu239 ID chart you attached.? Is that isotope identifier and library part of the free AMTEK DPP software download??? So far I have only been using the DPP software to acquire the MCA file and then processing it with Theremino.? I need to spend some time and learn the DPP MCA software also.
I don't understand your request about a Am241 only spectrum.? There is no clear 17.22 keV peak??(or other U x-rays) with Am241.? I equalized at the 59.5 keV counts and the two superimposed spectrums are attached.??
If you are trying to determine were the U x-rays are coming from in Trinitite, I think they are almost all associated with Pu239.? Yes the NU tamper was probably much larger than the Pu core, but if I am reading the charts right,? the specific activity of Pu239 is something like 5 orders of magnitude greater than U238/Pa234m.? The paper below indicates to me that Pu239 is much more active (see figure 2 and table 2) than the U238.? Maybe I just don't understand what you are doing.
Just for fun, I took a look at NU Fiestaware with the SiPin.? I saw a lot of Th x-rays (associated with U238 and U235 decay?) and Pb x-rays (florescence from the glaze?).? Surprisingly, I didn't see much in the way of U x-rays
Mike L.
