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.?
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Adding to the Wiki
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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?]
NOTE- every electron in all the elements together occupy an individual and discreet energy band. No two electrons from the same or different elements are the same. Geo
Of course, every electron, per se, is exactly identical to every other electron. In an atomic context: Electrons can, however, occupy discrete energy levels within any given atom of any given element. Identical elements, in their ground energy state, have all their electrons occupying identical energy levels. Identical elements in different energy states will have one or more electrons that occupy different energy levels. Two electrons can occupy one atomic energy level only if their spin states are opposed.
What you said is what I was trying to say I think. If we detect an X-Ray we can tell what shell it came from and what shell it was that filled it.
"Of course, every electron, per se, is exactly identical to every other electron. " At rest yes, but when not at rest, doesn't their weight increase as a factor of speed, especially at relativistic speeds (i.e. >511 keV kinetic)?
NOTE- every electron in all the elements together occupy an individual and discreet energy band. No two electrons from the same or different elements are the same. Geo
Of course, every electron, per se, is exactly identical to every other electron. In an atomic context: Electrons can, however, occupy discrete energy levels within any given atom of any given element. Identical elements, in their ground energy state, have all their electrons occupying identical energy levels. Identical elements in different energy states will have one or more electrons that occupy different energy levels. Two electrons can occupy one atomic energy level only if their spin states are opposed.
NOTE- every electron in all the elements together occupy an individual and discreet energy band. No two electrons from the same or different elements are the same. Geo
Of course, every electron, per se, is exactly identical to every other electron. In an atomic context: Electrons can, however, occupy discrete energy levels within any given atom of any given element. Identical elements, in their ground energy state, have all their electrons occupying identical energy levels. Identical elements in different energy states will have one or more electrons that occupy different energy levels. Two electrons can occupy one atomic energy level only if their spin states are opposed.
Americium? vs. Plutonium via? Neptunium vs. Uranium Daughter XRF.
?
Part 2.1
?
Gathering baseline scans of? Uranium XRF.
?
Equipment used:
Amptek GEO-1-2-3 with integral DPP/PC5 electronics and Si-PIN detector with preamplifier, external Amptek 5V 2A switching power supply wall-wart for power.
Controlling computer is a 32 bit ACER ASPIRE ONE?NOTEBOOK with WIN10 running Amptek?DPPMCA control and analysis program, USB connected.
Source being tested, suspected Trinity debris suspected of containing a small amount of Am.
To the casual observer this might look perfectly normal for a simple Am scan, with the lower energies easily mistaken for Np XRF. Closer examination actually reveals, in my opinion at this time,? Np + U XRF combined in those peaks and they can be separated.
Americium? vs. Plutonium via? Neptunium vs. Uranium Daughter XRF.
?
Part 2
?
Gathering baseline scans of Neptunium XRF.
?
Equipment used:
Amptek GEO-1-2-3 with integral DPP/PC5 electronics and Si-PIN detector with preamplifier, external Amptek 5V 2A switching power supply wall-wart for power.
Controlling computer is a 32 bit ACER ASPIRE ONE?NOTEBOOK with WIN10 running Amptek DPPMCA control and analysis program, USB connected.
Source being tested, <1uCi Am in a smoke detector.
Procedure- By experiment it was determined that ~8 seconds of run time would give an approximate peak height of the selected Lb1 XRF peak as compared to the nearby peak of the unknow subject's 10H run.
The quick 8 second scan has provided us with all the information needed, will be used as a direct calibration reference later when the two are compared together on the same screen. Of particular importance is the slope line between 17.75 (Np-Lb1 X-Ray) and 59.5 (Am Gamma Ray). This gives a visual clue as to what Am actually should look like, when tested by this particular Si-PIN sensor. This becomes a key tool when we compare what we think are U XRF slope to 59.5. If the slope is different, then the peak we are looking at is possibly modified by another, otherwise invisible source.
Americium? vs. Plutonium via? Neptunium vs. Uranium Daughter XRF.
Part 1: PREFACE
We always see Gamma Rays and X-Rays listed in the decay chain of radioactive atoms. Also Alpha radiation and some sort of Beta radiation.
Alpha and Beta (includes negatrons and positrons, and electron capture) are decay modes of parent atoms, the photons all come from the newly created created daughters. Knowing this often confusing and overlooked fact immensely helps us determine a great deal from our measurements.
The radioactive element (radioisotope)? Gamma Ray Isotope ID?charts and programs list all the electromagnetic emissions from each radioisotope, but some list them all together while others list them as to their origins, for example Gamma Rays (that come from nuclei), and X-Rays (that come from the electron shell area). Older references didn't recognize the origin so listed them by an arbitrary energy limit that to them represented the mythical dividing line between low X-Rays, and higher Gamma Ray energies. In truth there can be Gamma rays at low energies and X-Rays at incredibly high energies. Also in truth the concept of "low" and "high" are misnomers and should be stated as merely lower or higher in some form of reference. If the source is not known, the correct reference to a measured electromagnetic photon in the ionizing range is simply "photon".
Fortunately Gamma Rays and X-Rays come in very precise energies so we can use them to determine the origin but only by comparing to known XRF periodic tables and Gamma Spectrum analysis "catalogs".
Still today there is a great deal of inaccurate information coming from so called learned people RE: X? vs. Gamma Rays
Geo,
The plutonium teardrop is wonderful...beautiful indeed.
My question was for the examples in Feb 18th post #814 - they do not resemble
any of the typical Trinitite examples I have seen, where these obtained via H.
Baldwin?
Thanks,
TM
Geo,
The plutonium teardrop is wonderful...beautiful indeed.
My question was for the examples in Feb 18th post #814 - they do not resemble
any of the typical Trinitite examples I have seen, where these obtained via H.
Baldwin?
Thanks,
TM
Good
summary Geo. Technically Trinitite is the surface soils flash melted in-situ by
the fireball prompt gamma and x-rays. The beads and dumb bells are fallout
which has both a volatile and refractory component which separates out over
time and distance. Fallout ranges from mm size beads, dumbbells and tear drops to
nm size particulates. The larger heavier material (tear drops and dumb bells) drop
out down along the shaft while the lighter refractory material is carried further
downwind segregating by size and wt as spherical beads. These are seen as dark spherical
beads decreasing in size as you go down range in the plume and are easy to find
even a mile or so away. The finer refractory¡¯s and the volatiles are carried
long distances and are what most would consider the proper fallout. The
isotopic composition also changes with distance in the plume and the distance
from SGZ in the trinitite.
Tektites
are formed in freefall (in the atmosphere) and cool to solid before hitting the
ground. Notice the clear glass like appearance and inclusions both inside and
on the surface. The dots are actually spheres of melt glass that collided with
the falling, already solidified base. These teardrops are actually broken
halves of a spinning dogbone shape which formed in the cloud from a rapidly
spinning glob. Many pieces of ground based Trinitite contain perfectly formed
spheres of dark (appear black) tektites (genesis from iron I'm told), some I have
are inside the still hot but solidified surface craters that have already burst
from hot gasses from the soil.?
?
Red
Trinitite was formed by the jets of copper plasma travelling down the sensor
feed coaxial cable bundles as can be seen in the first few microseconds of the
flashball forming. These look like spikes on the still small ball. Steel guy
wires on other tower shots exhibit similar spike features.
?
Only
a small portion of the plutonium was consumed, the rest still exists in the
Trinitite and somewhat in the fallout. Unlike the radio-iodine's, cesium and
strontium fission products which would gasify easily,? plutonium and
uranium probably didn't propagate to far away places (my opinion).
?
Ground
based Trinitite contains the Europium isotopes, which were mostly formed from
natural europium in the soil by neutron activation, helped by water in the soil
from early morning rainfall before the shot. Ordinary water is of course
hydrogenous (hydrogen bearing) and hydrogen is a good moderator (slowing down
of) fast neutrons. Moderated neutrons have a much easier time of activating
other atoms than fast ones.
Geo,
I have to ask, I have never seen Trinitite look like the samples with the
painted dots, maybe because of the magnification but again I have not seen any
without broken edges that show the typical porous glassy appearance.
I must be missing something here.
TM
OK I'm with you now TM. No those are solid metal (mild steel), probably from the bomb casing and/or the tower. I know of 3 such samples only and have tested all 3 for fission product inclusion. Only the surface was melted, except for one sample which is roundish and melted all the way around (I named it the blob), as if it was spinning in a great heat, but even then not liquified.
Geo, The plutonium teardrop is wonderful...beautiful indeed. My question was for the examples in Feb 18th post #814 - they do not resemble any of the typical Trinitite examples I have seen, where these obtained via H. Baldwin? Thanks, TM
Tektites are formed in freefall (in the atmosphere) and cool to solid before hitting the ground. Notice the clear glass like appearance and inclusions both inside and on the surface. The dots are actually spheres of melt glass that collided with the falling, already solidified base. These teardrops are actually broken halves of a spinning dogbone shape which formed in the cloud from a rapidly spinning glob. Many pieces of ground based Trinitite contain perfectly formed spheres of dark (appear black) tektites (genesis from iron I'm told), some I have are inside the still hot but solidified surface craters that have already burst from hot gasses from the soil.?
Red Trinitite was formed by the jets of copper plasma travelling down the sensor feed coaxial cable bundles as can be seen in the first few microseconds of the flashball forming. These look like spikes on the still small ball. Steel guy wires on other tower shots exhibit similar spike features.
Only a small portion of the plutonium was consumed, the rest still exists in the Trinitite and somewhat in the fallout. Unlike the radio-iodine's, cesium and strontium fission products which would gasify easily,? plutonium and uranium probably didn't propagate to far away places (my opinion).
Ground based Trinitite contains the Europium isotopes, which were mostly formed from natural europium in the soil by neutron activation, helped by water in the soil from early morning rainfall before the shot. Ordinary water is of course hydrogenous (hydrogen bearing) and hydrogen is a good moderator (slowing down of) fast neutrons. Moderated neutrons have a much easier time of activating other atoms than fast ones.
Geo, I have to ask, I have never seen Trinitite look like the samples with the painted dots, maybe because of the magnification but again I have not seen any without broken edges that show the typical porous glassy appearance. I must be missing something here. TM
Geo, I have to ask, I have never seen Trinitite look like the samples with the painted dots, maybe because of the magnification but again I have not seen any without broken edges that show the typical porous glassy appearance. I must be missing something here. I created a Trinitite photo album on this site but not sure how members can view or contribute or if they are desirable. TM
I
can run a quantitative XRF analysis on your specimen and have a background in
nuclear forensics having worked on post-det debris analysis at the Nevada Test
Site. Red Trinitite is pretty unusual and a nice piece for your collection.
Hello forum,
I enjoyed reading your posts on the Red Trinitite...
Briefly,
I am a avid collector of Trinitite, Atomic material from Hiroshima and
Nagasaki. I? have many specimens from H. Baldwin collection and have
emailed communication with W. Kolb.?
I have some very unusual pieces, the one that stands out to me I put as my
profile picture. Deeply embedded metallic spheres and chunks of metal...
None of my specimens have been tested, other that the analysis done by
scientists who have worked with the examples that Baldwin provided to them.
My asking is that I would love to have an non destructive analysis done to this
unique sample...and in so, would donate a Red Trinitite sample for a written
copy of the test results for my records and use. Thank you if any interest,
Cheers.
TM?
I would be happy to do a detailed XRF of your specimen.? I can provide you with sample scans to show you what I can do.? Attached is a trinitite scan that I recently did.
Note that with my XRF I can show peaks up to about 100keV.? Beyond that I would use NaI to see higher energy isotopes.
Hello forum, I enjoyed reading your posts on the Red Trinitite... Briefly, I am a avid collector of Trinitite, Atomic material from Hiroshima and Nagasaki. I? have many specimens from H. Baldwin collection and have emailed communication with W. Kolb.? I have some very unusual pieces, the one that stands out to me I put as my profile picture. Deeply embedded metallic spheres and chunks of metal... None of my specimens have been tested, other that the analysis done by scientists who have worked with the examples that Baldwin provided to them. My asking is that I would love to have an non destructive analysis done to this unique sample...and in so, would donate a Red Trinitite sample for a written copy of the test results for my records and use. Thank you if any interest, Cheers. TM?
Hello forum, I enjoyed reading your posts on the Red Trinitite... Briefly, I am a avid collector of Trinitite, Atomic material from Hiroshima and Nagasaki. I? have many specimens from H. Baldwin collection and have emailed communication with W. Kolb.? I have some very unusual pieces, the one that stands out to me I put as my profile picture. Deeply embedded metallic spheres and chunks of metal... None of my specimens have been tested, other that the analysis done by scientists who have worked with the examples that Baldwin provided to them. My asking is that I would love to have an non destructive analysis done to this unique sample...and in so, would donate a Red Trinitite sample for a written copy of the test results for my records and use. Thank you if any interest, Cheers. TM?
Hello forum, I enjoyed reading your posts on the Red Trinitite... Briefly, I am a avid collector of Trinitite, Atomic material from Hiroshima and Nagasaki. I? have many specimens from H. Baldwin collection and have emailed communication with W. Kolb.? I have some very unusual pieces, the one that stands out to me I put as my profile picture. Deeply embedded metallic spheres and chunks of metal... None of my specimens have been tested, other that the analysis done by scientists who have worked with the examples that Baldwin provided to them. My asking is that I would love to have an non destructive analysis done to this unique sample...and in so, would donate a Red Trinitite sample for a written copy of the test results for my records and use. Thank you if any interest, Cheers. TM?
Okay, seller refunded purchase cost right away!? No word on returning broken item yet, will see.? But at most I'm disappointed to not get a working tube, but not out any money.? If they don't want it back, then I have a few parts to play with.? Would be very interesting to test shielding capacity of the housing.? Obviously it works very well for xrays at least!
On Sat, Aug 1, 2020 at 12:53 PM Nick Andrews via <nickjandrews=[email protected]> wrote:
Yes the glass is very dark as you can see.? My guess is the spring goes between the end of the copper anode(?) and the brass contact patch in the HV end of the housing to conduct the hv.? That's how my powder XRD machine is set up.? Just odd that there's a tapped hole in the end. Notice the copper rod is bent.? ?I kept it out when I reassembled the housing,? for testing.?
Don't know if the ring around the Be window is stainless or what. Or how it's sealed to the copper, probably epoxy.? Very nicely made stainless housing.? Joints sealed with o rings.?
I may not get a response from seller until Monday.?
Yes the tungsten would be on the angled part, just at the beryllium window. The copper rod helps carry away the heat as most of the electrons are turned into heat.
What a mess and someone knew, hoping to pass it off as shipping damage?
I would suspect considerable lead glass in the envelope.
Geo
From: "Nick Andrews" <nickjandrews@...> To: "XRF" <[email protected]> Sent: Saturday, August 1, 2020 2:55:36 AM Subject: Re: [XRF] Impulse offer accepted...
I think someone has been into it already,? unless the threaded hole in the copper central rod was simply from manufacturing.? The zip ties seen in auction listing pictures aren't on it,? just some packing tape.? ?
Not seeing the target,? unless the silvery spot on angled end of the rod is a piece of W.? Or is the silver ring around the window part of it?? ?The Be window might be salvageable.?
Most of the oil was gone from the cavity.? While there was blue paint on one screw at each joint,? that could easily be a dot of applied loctite or something.?
If you get to keep it with a full refund, maybe you can scrap it for the tungsten and other XRF-able elements inside?
Geo
----- Original Message ----- From: Nick Andrews <nickjandrews@...> To: [email protected] Sent: Fri, 31 Jul 2020 18:59:59 -0400 (EDT) Subject: Re: [XRF] Impulse offer accepted...
Well carp.? I finally got to the office and opened this up.? It's huge,? bigger than I expected.? ?Rattling noise sounds like a broken glass tube inside.? I imagine I should be able to open the housing and confirm.? Don't think it could be anything else.? ?Hope they don't hassle me about a return or refund.?
Guys I'm not familiar with that tube but I swear I saw a power supply for that 125- number recently. Maybe do a Google or even eBay search for that model # see what comes up. tick "include description".
The tag says tungsten target, that's good. So the tube has "a lot of potential" pun intended.
Not sure what it was originally used with.? But I have a few power supplies around here.? Several of the Glassman but they are -50kV as set up now.? Not sure how fine the control on those is but intend to do a test using precision pots to see how low the current can be managed.
I also have a Lixi PS-500 that has very fine control on the PS.? Not super high voltage either.
And I do happen to have a PGT HPGe unit!
On Fri, Jul 10, 2020 at 4:53 PM Dude <dfemer@...> wrote:
What does the HV plug in to? They don¡¯t show the end of the connector. What power supply does it use. Looks good enough to dose yourself with. It would be be nice with a CdTe or HPGe detector for high end XRF.
Well, I should've thought more before making offers, right?? Looks like a nice one though and up to 125kV, 10W tube.? Any thoughts?
--
Nick A
--
Nick A
"You know what I wish?? I wish that all the scum of the world had but a single throat, and I had my hands about it..."? Rorschach, 1975
"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety."- Benjamin Franklin, Historical Review of Pennsylvania, 1759
"Suburbia is where the developer bulldozes out the trees, then names the streets after them." Bill Vaughan
"The price of apathy towards public affairs is to be ruled by evil men." Plato
Yes the glass is very dark as you can see.? My guess is the spring goes between the end of the copper anode(?) and the brass contact patch in the HV end of the housing to conduct the hv.? That's how my powder XRD machine is set up.? Just odd that there's a tapped hole in the end. Notice the copper rod is bent.? ?I kept it out when I reassembled the housing,? for testing.?
Don't know if the ring around the Be window is stainless or what. Or how it's sealed to the copper, probably epoxy.? Very nicely made stainless housing.? Joints sealed with o rings.?
I may not get a response from seller until Monday.?
Yes the tungsten would be on the angled part, just at the beryllium window. The copper rod helps carry away the heat as most of the electrons are turned into heat.
What a mess and someone knew, hoping to pass it off as shipping damage?
I would suspect considerable lead glass in the envelope.
Geo
From: "Nick Andrews" <nickjandrews@...> To: "XRF" <[email protected]> Sent: Saturday, August 1, 2020 2:55:36 AM Subject: Re: [XRF] Impulse offer accepted...
I think someone has been into it already,? unless the threaded hole in the copper central rod was simply from manufacturing.? The zip ties seen in auction listing pictures aren't on it,? just some packing tape.? ?
Not seeing the target,? unless the silvery spot on angled end of the rod is a piece of W.? Or is the silver ring around the window part of it?? ?The Be window might be salvageable.?
Most of the oil was gone from the cavity.? While there was blue paint on one screw at each joint,? that could easily be a dot of applied loctite or something.?
If you get to keep it with a full refund, maybe you can scrap it for the tungsten and other XRF-able elements inside?
Geo
----- Original Message ----- From: Nick Andrews <nickjandrews@...> To: [email protected] Sent: Fri, 31 Jul 2020 18:59:59 -0400 (EDT) Subject: Re: [XRF] Impulse offer accepted...
Well carp.? I finally got to the office and opened this up.? It's huge,? bigger than I expected.? ?Rattling noise sounds like a broken glass tube inside.? I imagine I should be able to open the housing and confirm.? Don't think it could be anything else.? ?Hope they don't hassle me about a return or refund.?
Guys I'm not familiar with that tube but I swear I saw a power supply for that 125- number recently. Maybe do a Google or even eBay search for that model # see what comes up. tick "include description".
The tag says tungsten target, that's good. So the tube has "a lot of potential" pun intended.
Not sure what it was originally used with.? But I have a few power supplies around here.? Several of the Glassman but they are -50kV as set up now.? Not sure how fine the control on those is but intend to do a test using precision pots to see how low the current can be managed.
I also have a Lixi PS-500 that has very fine control on the PS.? Not super high voltage either.
And I do happen to have a PGT HPGe unit!
On Fri, Jul 10, 2020 at 4:53 PM Dude <dfemer@...> wrote:
What does the HV plug in to? They don¡¯t show the end of the connector. What power supply does it use. Looks good enough to dose yourself with. It would be be nice with a CdTe or HPGe detector for high end XRF.
Well, I should've thought more before making offers, right?? Looks like a nice one though and up to 125kV, 10W tube.? Any thoughts?
--
Nick A
--
Nick A
"You know what I wish?? I wish that all the scum of the world had but a single throat, and I had my hands about it..."? Rorschach, 1975
"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety."- Benjamin Franklin, Historical Review of Pennsylvania, 1759
"Suburbia is where the developer bulldozes out the trees, then names the streets after them." Bill Vaughan
"The price of apathy towards public affairs is to be ruled by evil men." Plato
SCOTT CAMPBELL
Nick Andrews
