I asked before with no response but since you are now down at Ca, it seems appropriate to check again.
Does anyone want a small sample of sodium metal, sealed under argon in glass.
Sounds fancy but it is (they are) just low pressure sodium vapor lamps pulled from
working fixtures. When cooled, the sodium vapor condenses to a small lump at the tip
of the bulb (they normally run upside down).
(I have the sockets and the 120VAC ballasts as well)
Randall
|
Re: FW: [XRF] 59.5keV spectrum cleanup
Charles,
My
mistake, I now see the problem you¡¯re using a log energy axis. That should always
be linear, counts can be log, lin or sqr as appropriate.
Dud
?
toggle quoted message
Show quoted text
From: [email protected]
[mailto:[email protected]] On Behalf Of Dude
Sent: Wednesday, October 28, 2020 10:10 AM
To: [email protected]
Subject: Re: FW: [XRF] 59.5keV spectrum cleanup
?
Charles,
Looking
at the png you sent there is something seriously wrong on the low energy below
4 keV. Send the mca file for a look as it may just be a Theremino problem. For
these low energies you¡¯ll want to keep the Np in there, but to pull these
elements out you really need a high flux rate which the Am source isn¡¯t doing.
Even with a tube the efficiencies are very poor and the counts are low making
it hard to quantify. However, the Al Si, P, S, Ca and K ?are absolutely
essential to determining the basic mineralogy types and every effort should be
made to verify their presence.
To
get the count times up readjust the gain to look only at the low energy range
say from 10 on down and see ff that helps pull them out. Using a tight focused
beam and close up to the target will also help concentrate the flux.
Dud
?
From: [email protected]
[mailto:[email protected]] On Behalf Of Charles David Young
Sent: Wednesday, October 28, 2020 8:12 AM
To: XRF
Subject: Re: FW: [XRF] 59.5keV spectrum cleanup
?
I agree and I did not mean to dis this exercise, even if it
turns out to be primarily academic.
When I get a chance I'll try the paper filter with a mineral
like Brannerite (UTi2O6) to see how it affects the Ti peak at 4.5keV.?
That is typically the lowest element that is essential to my application.?
Other peaks like P, K, Ca would be nice but I have learned to live without
them.? If we could somehow dig those out by an adjustment it would be
great.
?
"The filter comes at a cost.? Am I reading it
correctly that it reduced the input count to %25 of the non-filtered?? Do
we need to wait 4x longer for equal counts when this is used as an exciter?
"
All that is to be determined Charles. It well may be much
worse than that, if the low energies in the beam are what's helping to dig out
the low energy XRF signals we are looking for.
I agree about our perspective points of view too.?
You system is as ideal as can be for your main task, and
your display program is an advancement in the area of display and
identification, especially for the audience of that group. Now the photography
meets the same standard too. No one has added all those dimensions in one place
to the amateur mineral group before.? All for science' sake, and I applaud
that.
For you and others I would recommend trying a paper filter
over the exciter source, just to see.
The rest is for the X-Ray Physics and X-Ray Optics crowd. We
now have an inexpensive but powerful tool in our toolbox that wasn't there 2
days ago.
----- Original Message -----
From: Charles David Young <charlesdavidyoung@...>
To: XRF <[email protected]>
Sent: Wed, 28 Oct 2020 08:33:01 -0400 (EDT)
Subject: Re: FW: [XRF] 59.5keV spectrum cleanup
The filter comes at a cost.? Am I reading it correctly
that it reduced the input count to %25 of the non-filtered?? Do we need to
wait 4x longer for equal counts when this is used as an exciter?? Was all
that low energy activity that is filtered out detrimental or beneficial when
the button is used to stimulate XRF in the target?
I come at this from a different perspective.? I use the
Si-PIN with an Am241 exciter to identify minerals.? In my experience the
XRF coming from the target is much stronger than the noise introduced by the
Am241, which is mounted on a shield and facing away from the detector.?
Attached is a scan of xenotime, which shows a large Y component as well as some
U and Pb.? I turned on the Am241 reference lines to show that the Np and
Au peaks are very small in comparison.? One quickly learns to recognize
and ignore them when identifying the important peaks that emanate from the
target: Ti, Mn, Fe, Ta, Th, U, Y, Zr, Nb, REEs.
After trying many slight thickness variations of Source
Filter components, the best result is show in the second picture.
First up is the spectra coming out of the Am exciter source with just a paper
alpha blocking filter. That alone made significant improvements at the low end
vs no alpha filter. The goal of this project is to apply a filter to the source
that will effectively remove most of the low energy component that is caused by
Np- daughter and self-XRF of elements in the button, such as Au, Ag, Fe.
Error! Filename not specified.
Now a filter applied to the source and another Gamma Spectrum ran.
Error! Filename not specified.
Thanks to member Dudley Emer for the design of the filter elements and thicknesses,
based on selective filtering using the K-edge X-Ray absorption effect.
Geo
?
?
|
PLEASE
send the mca files A picture is pretty but allows nothing useful
Dud
toggle quoted message
Show quoted text
From: [email protected]
[mailto:[email protected]] On Behalf Of GEOelectronics@...
Sent: Wednesday, October 28, 2020 10:15 AM
To: [email protected]
Subject: [XRF] Ca Calcium XRF
?
Small piece of a broken CaF2 crystal.
Lot of room to the left of the 3.69 keV Ca Ka1 peak. The other peak to the
right is Kb1.
Exciter by ~35sec in 10 microampere 25kVp microfocus beam, unfiltered and in
STP air.
All the other junk is tube source artifacts.
Geo
|
Good on your calcium scan Charles. Here's same CaF2 shard with AmX8 exciter- again the other peaks are from the exciter- This one scan explains my quest for a Source Filter. 
|
Yeah, I forgot that I actually see Ca pretty well.? It just does not show up too often in my minerals.? Here is a yttrofluorite: (Ca1-xYx)F2+x
Small piece of a broken CaF2 crystal. Lot of room to the left of the 3.69 keV Ca Ka1 peak. The other peak to the right is Kb1. Exciter by ~35sec in 10 microampere 25kVp microfocus beam, unfiltered and in STP air. All the other junk is tube source artifacts. Geo 
|
Small piece of a broken CaF2 crystal. Lot of room to the left of the 3.69 keV Ca Ka1 peak. The other peak to the right is Kb1. Exciter by ~35sec in 10 microampere 25kVp microfocus beam, unfiltered and in STP air. All the other junk is tube source artifacts. Geo 
|
Re: FW: [XRF] 59.5keV spectrum cleanup
Charles,
Looking
at the png you sent there is something seriously wrong on the low energy below
4 keV. Send the mca file for a look as it may just be a Theremino problem. For
these low energies you¡¯ll want to keep the Np in there, but to pull these
elements out you really need a high flux rate which the Am source isn¡¯t doing.
Even with a tube the efficiencies are very poor and the counts are low making
it hard to quantify. However, the Al Si, P, S, Ca and K ?are absolutely
essential to determining the basic mineralogy types and every effort should be made
to verify their presence.
To
get the count times up readjust the gain to look only at the low energy range
say from 10 on down and see ff that helps pull them out. Using a tight focused
beam and close up to the target will also help concentrate the flux.
Dud
?
toggle quoted message
Show quoted text
From: [email protected]
[mailto:[email protected]] On Behalf Of Charles David Young
Sent: Wednesday, October 28, 2020 8:12 AM
To: XRF
Subject: Re: FW: [XRF] 59.5keV spectrum cleanup
?
I agree and I did not mean to dis this exercise, even if it
turns out to be primarily academic.
When I get a chance I'll try the paper filter with a mineral
like Brannerite (UTi2O6) to see how it affects the Ti peak at 4.5keV.?
That is typically the lowest element that is essential to my application.?
Other peaks like P, K, Ca would be nice but I have learned to live without
them.? If we could somehow dig those out by an adjustment it would be
great.
?
"The filter comes at a cost.? Am I reading it
correctly that it reduced the input count to %25 of the non-filtered?? Do
we need to wait 4x longer for equal counts when this is used as an exciter?
"
All that is to be determined Charles. It well may be much
worse than that, if the low energies in the beam are what's helping to dig out
the low energy XRF signals we are looking for.
I agree about our perspective points of view too.?
You system is as ideal as can be for your main task, and
your display program is an advancement in the area of display and
identification, especially for the audience of that group. Now the photography
meets the same standard too. No one has added all those dimensions in one place
to the amateur mineral group before.? All for science' sake, and I applaud
that.
For you and others I would recommend trying a paper filter
over the exciter source, just to see.
The rest is for the X-Ray Physics and X-Ray Optics crowd. We
now have an inexpensive but powerful tool in our toolbox that wasn't there 2
days ago.
----- Original Message -----
From: Charles David Young <charlesdavidyoung@...>
To: XRF <[email protected]>
Sent: Wed, 28 Oct 2020 08:33:01 -0400 (EDT)
Subject: Re: FW: [XRF] 59.5keV spectrum cleanup
The filter comes at a cost.? Am I reading it correctly
that it reduced the input count to %25 of the non-filtered?? Do we need to
wait 4x longer for equal counts when this is used as an exciter?? Was all
that low energy activity that is filtered out detrimental or beneficial when
the button is used to stimulate XRF in the target?
I come at this from a different perspective.? I use the
Si-PIN with an Am241 exciter to identify minerals.? In my experience the
XRF coming from the target is much stronger than the noise introduced by the
Am241, which is mounted on a shield and facing away from the detector.?
Attached is a scan of xenotime, which shows a large Y component as well as some
U and Pb.? I turned on the Am241 reference lines to show that the Np and
Au peaks are very small in comparison.? One quickly learns to recognize
and ignore them when identifying the important peaks that emanate from the
target: Ti, Mn, Fe, Ta, Th, U, Y, Zr, Nb, REEs.
After trying many slight thickness variations of Source
Filter components, the best result is show in the second picture.
First up is the spectra coming out of the Am exciter source with just a paper
alpha blocking filter. That alone made significant improvements at the low end
vs no alpha filter. The goal of this project is to apply a filter to the source
that will effectively remove most of the low energy component that is caused by
Np- daughter and self-XRF of elements in the button, such as Au, Ag, Fe.
Error! Filename not specified.
Now a filter applied to the source and another Gamma Spectrum ran.
Error! Filename not specified.
Thanks to member Dudley Emer for the design of the filter elements and
thicknesses, based on selective filtering using the K-edge X-Ray absorption
effect.
Geo
?
?
|
Re: FW: [XRF] 59.5keV spectrum cleanup
Wanna try this one again
Dud
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of GEOelectronics@... Sent: Wednesday, October 28, 2020 9:22 AM To: [email protected]Subject: Re: FW: [XRF] 59.5keV spectrum cleanup <div>Thickness of the layers of the most aggressive Source Filter Stack (to make it less aggressive, reduce the Cu first then the Ti) </div><div>Cu= .004" = 4mil = 100um</div><div>Ti= .001" = 1 mil = 25um</div><div>Al= .004" = 4mil = 100um</div><div><br data-mce-bogus="1"></div><div>The thinnest copper tried was 2mil, the thinnest Ti was 0.5mil, thinnest Al 4mil (Pepsi can material)<br data-mce-bogus="1"></div><div>Starting at the side the source injects the beam Cu then Ti then Al on the side facing the target, be that a sensor or a target being XRF'ed.</div><div><br data-mce-bogus="1"></div><div><div><br></div><div>The particular order of the elements is required just as we do in graded shielding of Gamma Ray probes and for the same reasons.</div></div><div><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>All worked, it was just the matter of degree of attenuation desired at the lows and tolerable attenuation at 59.5, which is subjective.</div><div><br data-mce-bogus="1"></div><div>This combination of elements relies on the K-edge effect of selective X-Ray absorption at a particular element's K-edge energy, where an abrupt discontinuity exists, all elements having a unique energy. For the curious, yes there are other "edges" for each electron shell.</div><div><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>My first approach was using the more subtle attenuation characteristic curve of only one element - Al (aluminum). This is still of interest and was the first step that would have lead to edge-absorption, but that was going to be in a future chapter. I like to learn by doing, and in a linear way. One step at a time usually.</div><div><br data-mce-bogus="1"></div><div>Geo</div><div><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div><br></div><div>----- Original Message -----<br>From: Dude <dfemer@...><br>To: [email protected]<br>Sent: Tue, 27 Oct 2020 19:28:26 -0400 (EDT)<br>Subject: Re: FW: [XRF] 59.5keV spectrum cleanup<br></div><div><br></div><div><style>/*<![CDATA[*/p.MsoNormal, li.MsoNormal, div.MsoNormal {<br> margin: 0.0in;<br> font-size: 12.0pt;<br> font-family: "Times New Roman" , serif;<br>}<br>a:link, span.MsoHyperlink {<br> color: blue;<br> text-decoration: underline;<br>}<br>a:visited, span.MsoHyperlinkFollowed {<br> color: purple;<br> text-decoration: underline;<br>}<br>p {<br> margin-right: 0.0in;<br> margin-left: 0.0in;<br> font-size: 12.0pt;<br> font-family: "Times New Roman" , serif;<br>}<br>p.MsoNoSpacing, li.MsoNoSpacing, div.MsoNoSpacing {<br> margin: 0.0in;<br> font-size: 16.0pt;<br> font-family: Arial , sans-serif;<br> color: black;<br>}<br>span.EmailStyle19 {<br> font-family: Arial , sans-serif;<br> color: black;<br> font-weight: normal;<br> font-style: normal;<br>}<br>*.MsoChpDefault {<br>}<br>div.Section1 {<br> page: Section1;<br>}<br>/*]]>*/</style></div><div class="Section1"><p class="MsoNormal"><span style="font-family: 'arial' , 'sans-serif'; color: black;" data-mce-style="font-family: 'arial' , 'sans-serif'; color: black;">This<br>will be interesting, What thicknesses are you running on these? </span></p><p class="MsoNormal"><span style="font-family: 'arial' , 'sans-serif'; color: black;" data-mce-style="font-family: 'arial' , 'sans-serif'; color: black;">Dud</span></p><p class="MsoNormal"><span style="font-family: 'arial' , 'sans-serif'; color: black;" data-mce-style="font-family: 'arial' , 'sans-serif'; color: black;"> </span></p><div style="border: none; border-top: solid #b5c4df 1pt; padding: 3pt 0in 0in 0in;" data-mce-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';" data-mce-style="font-size: 10pt; font-family: 'tahoma' , 'sans-serif';">From:</span></b><span style="font-size: 10pt; font-family: 'tahoma' , 'sans-serif';" data-mce-style="font-size: 10pt; font-family: 'tahoma' , 'sans-serif';"> [email protected]<br>[mailto: [email protected]] <b>On Behalf Of </b>GEOelectronics@...<br><b>Sent:</b> Tuesday, October 27, 2020 3:00 PM<br><b>To:</b> [email protected]<br><b>Subject:</b> Re: FW: [XRF] 59.5keV spectrum cleanup</span></p></div><p class="MsoNormal"> </p><p class="MsoNormal">No but we're analyzing it's ray pattern.<br><br><br>Here's the next step, it's a redo of the Source Filter test (which I built<br>close to but not exactly to your specifications, will clean that up later in<br>the shop) with the Cu close to the source rather than the sensor side, allowing<br>the Ti and Al to attenuate the cu characteristic X-Rays that showed up on the<br>last plot.<br><br><br>More tests tomorrow, this has been real-time, making adjustments per<br>recommendations.<br><br><br>Great fun<br><br><br>PS in between these trials, the Ba-133 testing was running on another<br>instrument. Will post that tomorrow. Looks good.<br><br><br>Geo</p><div><p class="MsoNormal"><br></p><br></div></div><div style="color: white;" data-mce-style="color: white;"></div><div><br></div><div><br></div><div><br></div>
|
Re: FW: [XRF] 59.5keV spectrum cleanup
Charles
and Geo
Attach
the mca files so we can look at the data, it¡¯s really hard to interpret
anything from a picture.
The
loss of the low energy Np will be detrimental to xrf of the low energy elements
where it helps to activate them but it will be beneficial to clear up the Np interferences
and allow a better LOD and confirmations for Zr, Mo, Sr, U, Y Nb and others.
Geo
try a shot on a rock target with and without the filter for a long count time.
Lest see what we get difference wise.
Dud
?
toggle quoted message
Show quoted text
From: [email protected]
[mailto:[email protected]] On Behalf Of Charles David Young
Sent: Wednesday, October 28, 2020 5:33 AM
To: XRF
Subject: Re: FW: [XRF] 59.5keV spectrum cleanup
?
The filter comes at a cost.? Am I reading it correctly
that it reduced the input count to %25 of the non-filtered?? Do we need to
wait 4x longer for equal counts when this is used as an exciter?? Was all
that low energy activity that is filtered out detrimental or beneficial when
the button is used to stimulate XRF in the target?
I come at this from a different perspective.? I use the
Si-PIN with an Am241 exciter to identify minerals.? In my experience the
XRF coming from the target is much stronger than the noise introduced by the
Am241, which is mounted on a shield and facing away from the detector.?
Attached is a scan of xenotime, which shows a large Y component as well as some
U and Pb.? I turned on the Am241 reference lines to show that the Np and
Au peaks are very small in comparison.? One quickly learns to recognize
and ignore them when identifying the important peaks that emanate from the
target: Ti, Mn, Fe, Ta, Th, U, Y, Zr, Nb, REEs.
?
After trying many slight thickness variations of Source
Filter components, the best result is show in the second picture.
First up is the spectra coming out of the Am exciter source with just a paper
alpha blocking filter. That alone made significant improvements at the low end
vs no alpha filter. The goal of this project is to apply a filter to the source
that will effectively remove most of the low energy component that is caused by
Np- daughter and self-XRF of elements in the button, such as Au, Ag, Fe.
Now a filter applied to the source and another Gamma Spectrum ran.
Thanks to member Dudley Emer for the design of the filter elements and
thicknesses, based on selective filtering using the K-edge X-Ray absorption
effect.
Geo
|
Re: FW: [XRF] 59.5keV spectrum cleanup
toggle quoted message
Show quoted text
<div>Thickness of the layers of the most aggressive Source Filter Stack (to make it less aggressive, reduce the Cu first then the Ti) </div><div>Cu= .004" = 4mil = 100um</div><div>Ti= .001" = 1 mil = 25um</div><div>Al= .004" = 4mil = 100um</div><div><br data-mce-bogus="1"></div><div>The thinnest copper tried was 2mil, the thinnest Ti was 0.5mil, thinnest Al 4mil (Pepsi can material)<br data-mce-bogus="1"></div><div>Starting at the side the source injects the beam Cu then Ti then Al on the side facing the target, be that a sensor or a target being XRF'ed.</div><div><br data-mce-bogus="1"></div><div><div><br></div><div>The particular order of the elements is required just as we do in graded shielding of Gamma Ray probes and for the same reasons.</div></div><div><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>All worked, it was just the matter of degree of attenuation desired at the lows and tolerable attenuation at 59.5, which is subjective.</div><div><br data-mce-bogus="1"></div><div>This combination of elements relies on the K-edge effect of selective X-Ray absorption at a particular element's K-edge energy, where an abrupt discontinuity exists, all elements having a unique energy. For the curious, yes there are other "edges" for each electron shell.</div><div><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>My first approach was using the more subtle attenuation characteristic curve of only one element - Al (aluminum). This is still of interest and was the first step that would have lead to edge-absorption, but that was going to be in a future chapter. I like to learn by doing, and in a linear way. One step at a time usually.</div><div><br data-mce-bogus="1"></div><div>Geo</div><div><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div><br></div><div>----- Original Message -----<br>From: Dude <dfemer@...><br>To: [email protected]<br>Sent: Tue, 27 Oct 2020 19:28:26 -0400 (EDT)<br>Subject: Re: FW: [XRF] 59.5keV spectrum cleanup<br></div><div><br></div><div><style>/*<![CDATA[*/p.MsoNormal, li.MsoNormal, div.MsoNormal {<br> margin: 0.0in;<br> font-size: 12.0pt;<br> font-family: "Times New Roman" , serif;<br>}<br>a:link, span.MsoHyperlink {<br> color: blue;<br> text-decoration: underline;<br>}<br>a:visited, span.MsoHyperlinkFollowed {<br> color: purple;<br> text-decoration: underline;<br>}<br>p {<br> margin-right: 0.0in;<br> margin-left: 0.0in;<br> font-size: 12.0pt;<br> font-family: "Times New Roman" , serif;<br>}<br>p.MsoNoSpacing, li.MsoNoSpacing, div.MsoNoSpacing {<br> margin: 0.0in;<br> font-size: 16.0pt;<br> font-family: Arial , sans-serif;<br> color: black;<br>}<br>span.EmailStyle19 {<br> font-family: Arial , sans-serif;<br> color: black;<br> font-weight: normal;<br> font-style: normal;<br>}<br>*.MsoChpDefault {<br>}<br>div.Section1 {<br> page: Section1;<br>}<br>/*]]>*/</style></div><div class="Section1"><p class="MsoNormal"><span style="font-family: 'arial' , 'sans-serif'; color: black;" data-mce-style="font-family: 'arial' , 'sans-serif'; color: black;">This<br>will be interesting, What thicknesses are you running on these? </span></p><p class="MsoNormal"><span style="font-family: 'arial' , 'sans-serif'; color: black;" data-mce-style="font-family: 'arial' , 'sans-serif'; color: black;">Dud</span></p><p class="MsoNormal"><span style="font-family: 'arial' , 'sans-serif'; color: black;" data-mce-style="font-family: 'arial' , 'sans-serif'; color: black;"> </span></p><div style="border: none; border-top: solid #b5c4df 1pt; padding: 3pt 0in 0in 0in;" data-mce-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';" data-mce-style="font-size: 10pt; font-family: 'tahoma' , 'sans-serif';">From:</span></b><span style="font-size: 10pt; font-family: 'tahoma' , 'sans-serif';" data-mce-style="font-size: 10pt; font-family: 'tahoma' , 'sans-serif';"> [email protected]<br>[mailto: [email protected]] <b>On Behalf Of </b>GEOelectronics@...<br><b>Sent:</b> Tuesday, October 27, 2020 3:00 PM<br><b>To:</b> [email protected]<br><b>Subject:</b> Re: FW: [XRF] 59.5keV spectrum cleanup</span></p></div><p class="MsoNormal"> </p><p class="MsoNormal">No but we're analyzing it's ray pattern.<br><br><br>Here's the next step, it's a redo of the Source Filter test (which I built<br>close to but not exactly to your specifications, will clean that up later in<br>the shop) with the Cu close to the source rather than the sensor side, allowing<br>the Ti and Al to attenuate the cu characteristic X-Rays that showed up on the<br>last plot.<br><br><br>More tests tomorrow, this has been real-time, making adjustments per<br>recommendations.<br><br><br>Great fun<br><br><br>PS in between these trials, the Ba-133 testing was running on another<br>instrument. Will post that tomorrow. Looks good.<br><br><br>Geo</p><div><p class="MsoNormal"><br></p><br></div></div><div style="color: white;" data-mce-style="color: white;"></div><div><br></div><div><br></div><div><br></div>
|
Re: FW: [XRF] 59.5keV spectrum cleanup
Geo,
I agree and I did not mean to dis this exercise, even if it turns out to be primarily academic.
When I get a chance I'll try the paper filter with a mineral like Brannerite (UTi2O6) to see how it affects the Ti peak at 4.5keV.? That is typically the lowest element that is essential to my application.? Other peaks like P, K, Ca would be nice but I have learned to live without them.? If we could somehow dig those out by an adjustment it would be great.
Charles
"The filter comes at a cost.? Am I reading it correctly that it reduced the input count to %25 of the non-filtered?? Do we need to wait 4x longer for equal counts when this is used as an exciter? "
All that is to be determined Charles. It well may be much worse than that, if the low energies in the beam are what's helping to dig out the low energy XRF signals we are looking for.
I agree about our perspective points of view too.?
You system is as ideal as can be for your main task, and your display program is an advancement in the area of display and identification, especially for the audience of that group. Now the photography meets the same standard too. No one has added all those dimensions in one place to the amateur mineral group before.? All for science' sake, and I applaud that.
For you and others I would recommend trying a paper filter over the exciter source, just to see.
The rest is for the X-Ray Physics and X-Ray Optics crowd. We now have an inexpensive but powerful tool in our toolbox that wasn't there 2 days ago.
Geo
----- Original Message ----- From: Charles David Young < charlesdavidyoung@...> To: XRF < [email protected]> Sent: Wed, 28 Oct 2020 08:33:01 -0400 (EDT) Subject: Re: FW: [XRF] 59.5keV spectrum cleanup
The filter comes at a cost.? Am I reading it correctly that it reduced the input count to %25 of the non-filtered?? Do we need to wait 4x longer for equal counts when this is used as an exciter?? Was all that low energy activity that is filtered out detrimental or beneficial when the button is used to stimulate XRF in the target?
I come at this from a different perspective.? I use the Si-PIN with an Am241 exciter to identify minerals.? In my experience the XRF coming from the target is much stronger than the noise introduced by the Am241, which is mounted on a shield and facing away from the detector.? Attached is a scan of xenotime, which shows a large Y component as well as some U and Pb.? I turned on the Am241 reference lines to show that the Np and Au peaks are very small in comparison.? One quickly learns to recognize and ignore them when identifying the important peaks that emanate from the target: Ti, Mn, Fe, Ta, Th, U, Y, Zr, Nb, REEs.
Charles
After trying many slight thickness variations of Source Filter components, the best result is show in the second picture. First up is the spectra coming out of the Am exciter source with just a paper alpha blocking filter. That alone made significant improvements at the low end vs no alpha filter. The goal of this project is to apply a filter to the source that will effectively remove most of the low energy component that is caused by Np- daughter and self-XRF of elements in the button, such as Au, Ag, Fe. ![Single_Button_Alpha_Blocked_ONLY.png]() Now a filter applied to the source and another Gamma Spectrum ran. ![1-2.5milCu-3Ti-.090Al-Source_Filter.png]() Thanks to member Dudley Emer for the design of the filter elements and thicknesses, based on selective filtering using the K-edge X-Ray absorption effect. Geo
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Re: FW: [XRF] 59.5keV spectrum cleanup
"The filter comes at a cost.? Am I reading it correctly that it reduced the input count to %25 of the non-filtered?? Do we need to wait 4x longer for equal counts when this is used as an exciter? "
All that is to be determined Charles. It well may be much worse than that, if the low energies in the beam are what's helping to dig out the low energy XRF signals we are looking for.
I agree about our perspective points of view too.?
You system is as ideal as can be for your main task, and your display program is an advancement in the area of display and identification, especially for the audience of that group. Now the photography meets the same standard too. No one has added all those dimensions in one place to the amateur mineral group before.? All for science' sake, and I applaud that.
For you and others I would recommend trying a paper filter over the exciter source, just to see.
The rest is for the X-Ray Physics and X-Ray Optics crowd. We now have an inexpensive but powerful tool in our toolbox that wasn't there 2 days ago.
Geo
----- Original Message ----- From: Charles David Young <charlesdavidyoung@...> To: XRF < [email protected]> Sent: Wed, 28 Oct 2020 08:33:01 -0400 (EDT) Subject: Re: FW: [XRF] 59.5keV spectrum cleanup
The filter comes at a cost.? Am I reading it correctly that it reduced the input count to %25 of the non-filtered?? Do we need to wait 4x longer for equal counts when this is used as an exciter?? Was all that low energy activity that is filtered out detrimental or beneficial when the button is used to stimulate XRF in the target?
I come at this from a different perspective.? I use the Si-PIN with an Am241 exciter to identify minerals.? In my experience the XRF coming from the target is much stronger than the noise introduced by the Am241, which is mounted on a shield and facing away from the detector.? Attached is a scan of xenotime, which shows a large Y component as well as some U and Pb.? I turned on the Am241 reference lines to show that the Np and Au peaks are very small in comparison.? One quickly learns to recognize and ignore them when identifying the important peaks that emanate from the target: Ti, Mn, Fe, Ta, Th, U, Y, Zr, Nb, REEs.
Charles
After trying many slight thickness variations of Source Filter components, the best result is show in the second picture.
First up is the spectra coming out of the Am exciter source with just a paper alpha blocking filter. That alone made significant improvements at the low end vs no alpha filter. The goal of this project is to apply a filter to the source that will effectively remove most of the low energy component that is caused by Np- daughter and self-XRF of elements in the button, such as Au, Ag, Fe.
Now a filter applied to the source and another Gamma Spectrum ran.
Thanks to member Dudley Emer for the design of the filter elements and thicknesses, based on selective filtering using the K-edge X-Ray absorption effect.
Geo
|
Re: FW: [XRF] 59.5keV spectrum cleanup
The filter comes at a cost.? Am I reading it correctly that it reduced the input count to %25 of the non-filtered?? Do we need to wait 4x longer for equal counts when this is used as an exciter?? Was all that low energy activity that is filtered out detrimental or beneficial when the button is used to stimulate XRF in the target?
I come at this from a different perspective.? I use the Si-PIN with an Am241 exciter to identify minerals.? In my experience the XRF coming from the target is much stronger than the noise introduced by the Am241, which is mounted on a shield and facing away from the detector.? Attached is a scan of xenotime, which shows a large Y component as well as some U and Pb.? I turned on the Am241 reference lines to show that the Np and Au peaks are very small in comparison.? One quickly learns to recognize and ignore them when identifying the important peaks that emanate from the target: Ti, Mn, Fe, Ta, Th, U, Y, Zr, Nb, REEs.
Charles
After trying many slight thickness variations of Source Filter components, the best result is show in the second picture. First up is the spectra coming out of the Am exciter source with just a paper alpha blocking filter. That alone made significant improvements at the low end vs no alpha filter. The goal of this project is to apply a filter to the source that will effectively remove most of the low energy component that is caused by Np- daughter and self-XRF of elements in the button, such as Au, Ag, Fe.  Now a filter applied to the source and another Gamma Spectrum ran.  Thanks to member Dudley Emer for the design of the filter elements and thicknesses, based on selective filtering using the K-edge X-Ray absorption effect. Geo
|
Re: FW: [XRF] 59.5keV spectrum cleanup
After trying many slight thickness variations of Source Filter components, the best result is show in the second picture. First up is the spectra coming out of the Am exciter source with just a paper alpha blocking filter. That alone made significant improvements at the low end vs no alpha filter. The goal of this project is to apply a filter to the source that will effectively remove most of the low energy component that is caused by Np- daughter and self-XRF of elements in the button, such as Au, Ag, Fe.  Now a filter applied to the source and another Gamma Spectrum ran.  Thanks to member Dudley Emer for the design of the filter elements and thicknesses, based on selective filtering using the K-edge X-Ray absorption effect. Geo
|
Re: 59.5keV spectrum cleanup
Dud, I used the thickness you recommended. " you would use 150 um Cu , 25 um Ti, and a 300 um Al filter"
Super thin stuff. The AL is an alloy, it should be pure. Will work on that more tomorrow. These are shop-made, not the real ones which cost a fortune (hundreds$$) and are NIST certified etc.
Geo
From: "DFEMER" <dfemer@...> To: [email protected]Sent: Tuesday, October 27, 2020 6:28:26 PM Subject: Re: FW: [XRF] 59.5keV spectrum cleanup
This
will be interesting, What thicknesses are you running on these?
Dud
?
?
No but we're analyzing it's ray pattern.
Here's the next step, it's a redo of the Source Filter test (which I built
close to but not exactly to your specifications, will clean that up later in
the shop) with the Cu close to the source rather than the sensor side, allowing
the Ti and Al to attenuate the cu characteristic X-Rays that showed up on the
last plot.
More tests tomorrow, this has been real-time, making adjustments per
recommendations.
Great fun
PS in between these trials, the Ba-133 testing was running on another
instrument. Will post that tomorrow. Looks good.
Geo
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Re: FW: [XRF] 59.5keV spectrum cleanup
This
will be interesting, What thicknesses are you running on these?
Dud
?
toggle quoted message
Show quoted text
From: [email protected]
[mailto:[email protected]] On Behalf Of GEOelectronics@...
Sent: Tuesday, October 27, 2020 3:00 PM
To: [email protected]
Subject: Re: FW: [XRF] 59.5keV spectrum cleanup
?
No but we're analyzing it's ray pattern.
Here's the next step, it's a redo of the Source Filter test (which I built
close to but not exactly to your specifications, will clean that up later in
the shop) with the Cu close to the source rather than the sensor side, allowing
the Ti and Al to attenuate the cu characteristic X-Rays that showed up on the
last plot.
More tests tomorrow, this has been real-time, making adjustments per
recommendations.
Great fun
PS in between these trials, the Ba-133 testing was running on another
instrument. Will post that tomorrow. Looks good.
Geo
|
Re: FW: [XRF] 59.5keV spectrum cleanup
No but we're analyzing it's ray pattern.
Here's the next step, it's a redo of the Source Filter test (which I built close to but not exactly to your specifications, will clean that up later in the shop) with the Cu close to the source rather than the sensor side, allowing the Ti and Al to attenuate the cu characteristic X-Rays that showed up on the last plot.
More tests tomorrow, this has been real-time, making adjustments per recommendations.
Great fun
PS in between these trials, the Ba-133 testing was running on another instrument. Will post that tomorrow. Looks good.
Geo
|
Re: FW: [XRF] 59.5keV spectrum cleanup
Actually
there not much we can do for looking at the Am button as a sample. What the source
filter is designed for is using the Am buttons as a source where we need to get
rid of the Np interferences and how to optimize that.
What
thickness¡¯s were you using? Try this filter on an Am source and a mid to low Z target
sample with and without the filter.
Dud
?
toggle quoted message
Show quoted text
From: [email protected]
[mailto:[email protected]] On Behalf Of GEOelectronics@...
Sent: Tuesday, October 27, 2020 2:28 PM
To: [email protected]
Subject: Re: FW: [XRF] 59.5keV spectrum cleanup
?
Here's a better demonstration test.
An 1800sec scan was made using a single Am button, pointed directly at the
Si-PIN detector
Next the filter stack (Al-Ti-CU) was placed between the source and the Si-PIN.
This test was ran until the 59.5 peaks matched (1500s), as this is the area of
interest.
There was dramatic effect on the Np- X-Rays.
Fault- did pick up Cu XRF from filter. Next time will reverse the order of the
sheets in the stack, keeping copper more towards the source.
Geo
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Re: 59.5keV spectrum cleanup
It¡¯s
a source filter it goes in front of the excitation x-ray tube source. It relies
on the materials K-edges where the attenuation factors drop below that energy edge
but are attenuated above it. Energies below get lit up above are knocked down.
In this case we want to minimize the Np energies from the source and let the sample
energies shine through the interference. ?
So
state ?what¡¯s the objective, what filter, where, with what metal, what
thickness, what target, what source, count times? What¡¯s an edge filter?
Not
everyone knows what we¡¯re doing here¡fill in the blanks
Dud
?
?
toggle quoted message
Show quoted text
From: [email protected]
[mailto:[email protected]] On Behalf Of GEOelectronics@...
Sent: Tuesday, October 27, 2020 1:54 PM
To: [email protected]
Subject: Re: [XRF] 59.5keV spectrum cleanup
?
You
called it a source filter. It works by K-edge?
sFrom:
"DFEMER" <dfemer@...>
To:
[email protected]
Sent: Tuesday, October 27, 2020 3:40:29 PM
Subject: Re: FW: [XRF] 59.5keV spectrum cleanup
Geo,
We
know you know what you¡¯re doing but none of us know what you were doing. Please
also be descriptive in what we¡¯re looking at. Pretty pictures don¡¯t do much
without context. Write the experiment up
What
the objective, what filter, where, with what metal, what thickness, what
target, what source, count times? What¡¯s an edge filter?
Dud
?
?
Not a bad trial for a quicky. The
ratio of 59.5 to the lows really changed. Needs tweaking this end.
?
|
Re: FW: [XRF] 59.5keV spectrum cleanup
Here's a better demonstration test. An 1800sec scan was made using a single Am button, pointed directly at the Si-PIN detector Next the filter stack (Al-Ti-CU) was placed between the source and the Si-PIN. This test was ran until the 59.5 peaks matched (1500s), as this is the area of interest. There was dramatic effect on the Np- X-Rays. Fault- did pick up Cu XRF from filter. Next time will reverse the order of the sheets in the stack, keeping copper more towards the source. Geo 
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