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 If a piece of information is incorrect, a link outdated, or the presentation choppy or unclear, the user can just click "Edit Page" at the bottom and then fix the mistake.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?]
Yikes, Logans are classic, lathes too-sweet but dangerous.
Geo
From: "Nick Andrews" <nickjandrews@...> To: [email protected] Sent: Thursday, December 3, 2020 12:37:25 PM Subject: Re: [XRF] Welcome new member Justin.
Yes, welcome!? And to add on Geo's statement, many of us are into all sorts of related topics, like vacuum tube tech, high voltage, high energy physics/chemistry, and many are wannabe machinists.? I just bought a 8" Logan metal shaper when visiting my parents.? Talk about semi-obsolete technology...
Hi Justin and welcome to our small but intense group of XRF'ers. Also noticed you joined GammaSpectrometryGroup.
We try to keep XRF Group centered on advanced XRF topics (SDD, SI-PIN, CdTe, CZT detectors, NIM etc), and GammaSpectrometry for everything else having to do with advanced Gamma Spec work.?
For general radiation, detection thereof,? and all things THEREMINO, use the GammaSpectroscopy? (not GammaSPectrometry) group.
George Dowell "Geo"
PS many of us on all these groups are also Ham Radio enthusiasts.
Yikes, Logans are classic, lathes too-sweet but dangerous.
Geo
From: "Nick Andrews" <nickjandrews@...> To: [email protected] Sent: Thursday, December 3, 2020 12:37:25 PM Subject: Re: [XRF] Welcome new member Justin.
Yes, welcome!? And to add on Geo's statement, many of us are into all sorts of related topics, like vacuum tube tech, high voltage, high energy physics/chemistry, and many are wannabe machinists.? I just bought a 8" Logan metal shaper when visiting my parents.? Talk about semi-obsolete technology...
Hi Justin and welcome to our small but intense group of XRF'ers. Also noticed you joined GammaSpectrometryGroup.
We try to keep XRF Group centered on advanced XRF topics (SDD, SI-PIN, CdTe, CZT detectors, NIM etc), and GammaSpectrometry for everything else having to do with advanced Gamma Spec work.?
For general radiation, detection thereof,? and all things THEREMINO, use the GammaSpectroscopy? (not GammaSPectrometry) group.
George Dowell "Geo"
PS many of us on all these groups are also Ham Radio enthusiasts.
Long ago the inventor of "Thongs" the shoe not the underwear- was being interviewed. She said that she invented a way to glue layers of a certain plastic together to make them- in her kitchen. Only afterwards did she learn that scientists and plastics manufacturers considered glue that material successfully was impossible. Not being a trained chemist she was too stupid to know that.
sometimes trial-and-error actually works.
Geo
From: "Nick Andrews" <nickjandrews@...> To: [email protected] Sent: Thursday, December 3, 2020 12:37:25 PM Subject: Re: [XRF] Welcome new member Justin.
Yes, welcome!? And to add on Geo's statement, many of us are into all sorts of related topics, like vacuum tube tech, high voltage, high energy physics/chemistry, and many are wannabe machinists.? I just bought a 8" Logan metal shaper when visiting my parents.? Talk about semi-obsolete technology...
Hi Justin and welcome to our small but intense group of XRF'ers. Also noticed you joined GammaSpectrometryGroup.
We try to keep XRF Group centered on advanced XRF topics (SDD, SI-PIN, CdTe, CZT detectors, NIM etc), and GammaSpectrometry for everything else having to do with advanced Gamma Spec work.?
For general radiation, detection thereof,? and all things THEREMINO, use the GammaSpectroscopy? (not GammaSPectrometry) group.
George Dowell "Geo"
PS many of us on all these groups are also Ham Radio enthusiasts.
On Thu, Dec 3, 2020 at 2:19 PM Soren <justinhuber@...> wrote:
I bought a venerable old Tektronix 2645b for the same reason - last reparable oscilloscope.?
This microscope is an old Zeiss (West Germany) with some snazzy add-ons like the Epi-Illumination attachments (which offer great options for custom Raman and Fluorescence work) as well as some polarizers for petrographic analysis.?
It's nice to know of people's experience with vacuum tubes, HV, etc. There are a bunch of Spellman HV power supplies on eBay. And, the old Glassman service manuals give some good insights into basic HV power supply design topology. Reading through the Newton Scientific Patent on the mini X-ray tube make one wonder what is really novel about the design since it just uses most of the classic HV building blocks only in miniature.
There is a channel on YouTube - "Glasslinger" - where you get to watch the construction of custom vacuum tubes. If glassblowing is an esoteric art, then scientific vacuum tube glassblowing is something else entirely. There is even an episode on build a custom mini X-ray tube:?
Another great youtube channel is "Applied Science" where this guy Ben in California shows some interesting DIY projects - if you consider sputter coating, building a scanning electronic microscope from scratch, or cooling things to 4K with the cryocooler in your garage to be a DIY project. He has a few episodes on XRF and even one on making X-Rays by unrolling plastic tape (a process that has actually been patented). See:?
Another very well made channel is "Tech Ingredients" but focuses more on lasers, plasma, and magnetics.
I would agree with Charles
on the SiPin detector on the basis of cost vs resolution. The Si-Pins that we
see on ebay are 25mm^2 which is the lowest resolution version of these
detectors. An SDD has much better resolution and count rate but at a price. A
6mm^2 Si-Pin has about the same resolution as a 25mm^2 SDD but the SDD has a
10x better count rate while maintaining the resolution.? SDD¡¯s are useful in
high count rate high resolution situations and excel down in the lower energies
and at lower peaking times. At the higher energies where broadening is a factor
the two are getting to be comparable.
For a hobbyist application
the excitation source is really weak so the count rates are low and a Si-Pin
can use a higher peaking time to get better resolution while not worrying low
energy noise and about count rate limitations. And the price is much better and
does the job needed.
The digital stacks are tailored
to the detector at the factory and aren¡¯t interchangeable without a new software
flashcode as I understand it, Geo will know more about that.
Dud
?
From:[email protected] [mailto:[email protected]] On
Behalf Of Charles David Young Sent: Thursday, December 3, 2020
10:54 AM To: XRF Subject: Re: [XRF] Amptek SiPIN vs
FastSDD - Recommendations?
?
Hi Soren,
?
I'll just relate my experience with the Amptek SiPIN that I have been
using for a year or so.? It is great for helping me identify
minerals.? Even if I had the budget for an SDD I doubt I would go that
way.
?
You on the other hand may have an application where the SDD would have
serious advantages.? If you can justify the expense then by all means, go
for it.
?
You might give us an idea of your application.? If you don't have
anything specific and are just interested in learning about XRF then I would go
with the Amptek SiPIN.
On Thu, Dec 3, 2020 at 10:41 AM Soren <justinhuber@...> wrote:
I'm a bit new to the world of XRF and am currently using an old
scintillator probe and some NIM modules - but the resolution isn't great.
I've been looking at some Amptek setups on eBay and have been corresponding
with GEO and it was recommended that I post this question on the forum:
There are several complete Amptek systems for sale on eBay. (I hope this
question doesn't encourage someone to buy them before I do!) I'm trying to
understand the tradeoffs.
SiPIN system
25mm
SiPIN detector
PA230
preamp
DP5/PC5
stack for power and pulse processing.
This is one of the systems that Geo posted pictures of in June and
July. It would seem that the electronics are current model products.
FastSDD system
25mm Fast SDD - 500um - 0.5mm Be Window
PA230 - looks to be an early model of the PA230 Board
- Red PCB vs. normal Green/Blue PCB with fewer parts
DP5X - looks to be a simpler integrated version of the
DP5/PC5 board combo.
I've studied the pictures of the PA boards for which I could find pictures to
see how they have evolved over time. I've seen about four different versions,
which increase in complexity. But I'm not sure if this is a function of product
development over time or that one board may be designed for SiPIN vs SDD.
Anyway, I wonder if
anyone has some insight into the tradeoffs between the two complete systems
mentioned SiPIN vs FastSDD. One has the obviously better detector (SDD). The
other seems to have the better backend electronics (SiPIN) and is cheaper. I'd
love to have anyone's expertise if figuring out which may be the better option.
BTW, if anyone is curious, here are some of the patents which seem to show the
inner workings of some of the Amptek Systems:
US6,587,003B2 - Charge Sensitive Preamplifier
with Pulsed Reset Source - the secret sauce in low noise preamplifiers,
besides a good FET and OpAmp, is using a pulsed reset instead of a large
drain resister, which adds noise. This approach is explained in Amptek's
Reset Preamplifier Application Note.
US7448802 - Integrated X-Ray Source Module - The
X-ray source that Amptek sells appears to be made by Newton Scientific -
this is the schematic of the inner electronics which could be useful for
someone trying to repair one of these units. The reference for U10 which
is the main controller IC is conspicuously absent - but it looks to be the
UC1872/2872/3872 made by Unitrode
US7949099 - Compact High Voltage X Ray Source -
you can also look at how the tubes themselves are put together.
NOTE: These designs are
still under patent protect so I would not recommend that someone actually build
any of these - but they could be useful for repair. Thanks so much for your help.
I just reread you comments - I guess question 3 isn't as relevant...
Also, I see a lot of typos in my response. I really do know how to spell. It seems that some of my keyboard key are not working and spellcheck is working against me.
Thank. At this point I don't have many specific applications. I collect elements and minerals and it was be nice to analyze them for purity. I also have some artistic/archeological materials that would be nice to analyze - pigments, glass, etc. I imagine the SiPIN would be fine for that.?
I don't really care about the Fast in FastSDD as I don't have an sources that would produce enough cps to mater. The SDD seems appealing for several reasons:?
It gets you a little closer to 1keV which means some sensitivity to the lower-Z materials
It gives you more resolution for a given sized sensor.?
Given the two currently available options on eBay are a 25mm FastSDD and a 25mm SiPIN the SDD seems the better choice. If it was 25mm SDD vs 6mm SiPIN I think those are comparable. I realize that the DP5X is a stripped down board. It doesn't have a ethernet port and it doesn't have the DAC that gives you a signal output that you could view on an oscilloscope. I don't know how important those features are. The prices of the two are different, but within enough of a ballpark that both are worth considering.
I guess I have three concrete questions:
How much do you lose with with older electronics? Perhaps it's hard to get the FW6 upgrade?
How often does these things come up for sale that it's work waiting for the right setup?
Charles, you mention that you wouldn't go with the SDD, even if price wasn't an issue. Why is that? Is there a downside to the SDD?
I bought a venerable old Tektronix 2645b for the same reason - last reparable oscilloscope.?
This microscope is an old Zeiss (West Germany) with some snazzy add-ons like the Epi-Illumination attachments (which offer great options for custom Raman and Fluorescence work) as well as some polarizers for petrographic analysis.?
It's nice to know of people's experience with vacuum tubes, HV, etc. There are a bunch of Spellman HV power supplies on eBay. And, the old Glassman service manuals give some good insights into basic HV power supply design topology. Reading through the Newton Scientific Patent on the mini X-ray tube make one wonder what is really novel about the design since it just uses most of the classic HV building blocks only in miniature.
There is a channel on YouTube - "Glasslinger" - where you get to watch the construction of custom vacuum tubes. If glassblowing is an esoteric art, then scientific vacuum tube glassblowing is something else entirely. There is even an episode on build a custom mini X-ray tube:?
Another great youtube channel is "Applied Science" where this guy Ben in California shows some interesting DIY projects - if you consider sputter coating, building a scanning electronic microscope from scratch, or cooling things to 4K with the cryocooler in your garage to be a DIY project. He has a few episodes on XRF and even one on making X-Rays by unrolling plastic tape (a process that has actually been patented). See:?
Another very well made channel is "Tech Ingredients" but focuses more on lasers, plasma, and magnetics.
I wanted to weigh in on this thread about machine shops, lathes, etc.? As a farm kid who grew up around shop equipment and exposed PTO (power take off) shafts on tractors, I gained a lot of respect for moving equipment.?
?
I¡¯m not sure if this posted link will work for the rest of the group, but I thought it worth sharing as it is relevant to the discussion.? I just got this from an old high school buddy back in the farm country of Nebraska, although given the clothing in the video, I suspect it was likely in an oil field in the hinterlands of somewhere north.
?
?? ***WARNING*** !!? Graphic Content!!? As gruesome as this video is, I think it should be shown as required training in every machine shop, and even every high school shop class as to what damage an operating machine can produce.
?
?
Sorry if this upsets anyone, but it is a somber reminder of the power of equipment designed to easily cut and machine big metal parts.? A human body is a trifle to these machines.
Yikes, Logans are classic, lathes too-sweet but dangerous.
Geo
?
From: "Nick Andrews" <nickjandrews@...> To: [email protected] Sent: Thursday, December 3, 2020 12:37:25 PM Subject: Re: [XRF] Welcome new member Justin.
?
Yes, welcome!? And to add on Geo's statement, many of us are into all sorts of related topics, like vacuum tube tech, high voltage, high energy physics/chemistry, and many are wannabe machinists.? I just bought a 8" Logan metal shaper when visiting my parents.? Talk about semi-obsolete technology...
From: "Soren" <justinhuber@...> To: [email protected] Sent: Thursday, December 3, 2020 1:43:33 PM Subject: Re: [XRF] Welcome new member Justin.
Dear Geo,
Thanks. I'm a wannabe wannabe machinist. Right now, a wannabe welder - next year a wannabe machinist. Nice to hear that people are into HAM radio. Being a young person, I come from the SDR world of GNUradio, HackRF, and RTLSDR.?
I like to build/repair analytical equipment - especially vintage stuff that is actually made of discrete components (and which was made before I was born). I'm currently retrofitting an old Zeiss (West Germany) microscope with the optics to do some Raman Spectroscopy. The amazing thing about it is that, every single part screws together - nothing is welded - everything comes apart - it was meant to be repaired.
Thanks. I'm a wannabe wannabe machinist. Right now, a wannabe welder - next year a wannabe machinist. Nice to hear that people are into HAM radio. Being a young person, I come from the SDR world of GNUradio, HackRF, and RTLSDR.?
I like to build/repair analytical equipment - especially vintage stuff that is actually made of discrete components (and which was made before I was born). I'm currently retrofitting an old Zeiss (West Germany) microscope with the optics to do some Raman Spectroscopy. The amazing thing about it is that, every single part screws together - nothing is welded - everything comes apart - it was meant to be repaired.
Long ago the inventor of "Thongs" the shoe not the underwear- was being interviewed. She said that she invented a way to glue layers of a certain plastic together to make them- in her kitchen. Only afterwards did she learn that scientists and plastics manufacturers considered glue that material successfully was impossible. Not being a trained chemist she was too stupid to know that.
From: "Nick Andrews" <nickjandrews@...> To: [email protected] Sent: Thursday, December 3, 2020 12:37:25 PM Subject: Re: [XRF] Welcome new member Justin.
Yes, welcome!? And to add on Geo's statement, many of us are into all sorts of related topics, like vacuum tube tech, high voltage, high energy physics/chemistry, and many are wannabe machinists.? I just bought a 8" Logan metal shaper when visiting my parents.? Talk about semi-obsolete technology...
Hi Justin and welcome to our small but intense group of XRF'ers. Also noticed you joined GammaSpectrometryGroup.
We try to keep XRF Group centered on advanced XRF topics (SDD, SI-PIN, CdTe, CZT detectors, NIM etc), and GammaSpectrometry for everything else having to do with advanced Gamma Spec work.?
For general radiation, detection thereof,? and all things THEREMINO, use the GammaSpectroscopy? (not GammaSPectrometry) group.
George Dowell "Geo"
PS many of us on all these groups are also Ham Radio enthusiasts.
From: "Nick Andrews" <nickjandrews@...> To: [email protected] Sent: Thursday, December 3, 2020 12:37:25 PM Subject: Re: [XRF] Welcome new member Justin.
Yes, welcome!? And to add on Geo's statement, many of us are into all sorts of related topics, like vacuum tube tech, high voltage, high energy physics/chemistry, and many are wannabe machinists.? I just bought a 8" Logan metal shaper when visiting my parents.? Talk about semi-obsolete technology...
Hi Justin and welcome to our small but intense group of XRF'ers. Also noticed you joined GammaSpectrometryGroup.
We try to keep XRF Group centered on advanced XRF topics (SDD, SI-PIN, CdTe, CZT detectors, NIM etc), and GammaSpectrometry for everything else having to do with advanced Gamma Spec work.?
For general radiation, detection thereof,? and all things THEREMINO, use the GammaSpectroscopy? (not GammaSPectrometry) group.
George Dowell "Geo"
PS many of us on all these groups are also Ham Radio enthusiasts.
The FAST-SDD has a few advantages that could come in handy later on. "Fast" means it can gather a tremendous # of counts in a burst. This would be handy if you were looking above 50 keV for some XRF, say of heavy rare earths. Unfortunately most XRF generators max out at 50keV so to get 100keV, a totally different type of generator is used, and they don't stay on for very long, but can be much more powerful. This is where FAST SDD shines. ALL SDD's have slightly better resolution and most will go all the way down to 1 to 2 keV. They go lower due to thinner entrance windows which = more fragile.
DP5X is not a stack, but a single stripped down board.?
If you want to reproduce what you've seen here with our Si-PINs, then the choice is clear.
Please go back to the first message on this board if you have not done so, and follow our progress and improvements with this remarkable setup. Keep your Scintillator outfit, you'll need it to verify energies above 50- with good sensitivity.
Just recently I started running my Si-PIN from 0-100, but that's because of working with uranium and wanting to see the ~63 and 93 keV peaks. It's not sensitive up there but if you can be patient for a signal to build up, it is still accurate like crazy on them.
Yes, welcome!? And to add on Geo's statement, many of us are into all sorts of related topics, like vacuum tube tech, high voltage, high energy physics/chemistry, and many are wannabe machinists.? I just bought a 8" Logan metal shaper when visiting my parents.? Talk about semi-obsolete technology...
Hi Justin and welcome to our small but intense group of XRF'ers. Also noticed you joined GammaSpectrometryGroup.
We try to keep XRF Group centered on advanced XRF topics (SDD, SI-PIN, CdTe, CZT detectors, NIM etc), and GammaSpectrometry for everything else having to do with advanced Gamma Spec work.?
For general radiation, detection thereof,? and all things THEREMINO, use the GammaSpectroscopy? (not GammaSPectrometry) group.
George Dowell "Geo"
PS many of us on all these groups are also Ham Radio enthusiasts.
I'll just relate my experience with the Amptek SiPIN that I have been using for a year or so.? It is great for helping me identify minerals.? Even if I had the budget for an SDD I doubt I would go that way.
You on the other hand may have an application where the SDD would have serious advantages.? If you can justify the expense then by all means, go for it.
You might give us an idea of your application.? If you don't have anything specific and are just interested in learning about XRF then I would go with the
Amptek
SiPIN.
On Thu, Dec 3, 2020 at 10:41 AM Soren <justinhuber@...> wrote:
I'm a bit new to the world of XRF and am currently using an old scintillator probe and some NIM modules - but the resolution isn't great.
I've been looking at some Amptek setups on eBay and have been corresponding with GEO and it was recommended that I post this question on the forum:
There are several complete Amptek systems for sale on eBay. (I hope this question doesn't encourage someone to buy them before I do!) I'm trying to understand the tradeoffs.
SiPIN system
25mm SiPIN detector
PA230 preamp
DP5/PC5 stack for power and pulse processing.
This is one of the systems that Geo posted pictures of in June and July. It would seem that the electronics are current model products.
FastSDD system
25mm Fast SDD - 500um - 0.5mm Be Window
PA230 - looks to be an early model of the PA230 Board - Red PCB vs. normal Green/Blue PCB with fewer parts
DP5X - looks to be a simpler integrated version of the DP5/PC5 board combo.
I've studied the pictures of the PA boards for which I could find pictures to see how they have evolved over time. I've seen about four different versions, which increase in complexity. But I'm not sure if this is a function of product development over time or that one board may be designed for SiPIN vs SDD.
Anyway, I wonder if anyone has some insight into the tradeoffs between the two complete systems mentioned SiPIN vs FastSDD. One has the obviously better detector (SDD). The other seems to have the better backend electronics (SiPIN) and is cheaper. I'd love to have anyone's expertise if figuring out which may be the better option.
BTW, if anyone is curious, here are some of the patents which seem to show the inner workings of some of the Amptek Systems:
US6,587,003B2 - Charge Sensitive Preamplifier with Pulsed Reset Source - the secret sauce in low noise preamplifiers, besides a good FET and OpAmp, is using a pulsed reset instead of a large drain resister, which adds noise. This approach is explained in Amptek's Reset Preamplifier Application Note.
US7448802 - Integrated X-Ray Source Module - The X-ray source that Amptek sells appears to be made by Newton Scientific - this is the schematic of the inner electronics which could be useful for someone trying to repair one of these units. The reference for U10 which is the main controller IC is conspicuously absent - but it looks to be the UC1872/2872/3872 made by Unitrode
US7949099 - Compact High Voltage X Ray Source - you can also look at how the tubes themselves are put together.
NOTE: These designs are still under patent protect so I would not recommend that someone actually build any of these - but they could be useful for repair.
Hi Justin and welcome to our small but intense group of XRF'ers. Also noticed you joined GammaSpectrometryGroup.
We try to keep XRF Group centered on advanced XRF topics (SDD, SI-PIN, CdTe, CZT detectors, NIM etc), and GammaSpectrometry for everything else having to do with advanced Gamma Spec work.?
For general radiation, detection thereof,? and all things THEREMINO, use the GammaSpectroscopy? (not GammaSPectrometry) group.
George Dowell "Geo"
PS many of us on all these groups are also Ham Radio enthusiasts.
I'm a bit new to the world of XRF and am currently using an old scintillator probe and some NIM modules - but the resolution isn't great.
I've been looking at some Amptek setups on eBay and have been corresponding with GEO and it was recommended that I post this question on the forum:
There are several complete Amptek systems for sale on eBay. (I hope this question doesn't encourage someone to buy them before I do!) I'm trying to understand the tradeoffs.
SiPIN system
25mm SiPIN detector
PA230 preamp
DP5/PC5 stack for power and pulse processing.
This is one of the systems that Geo posted pictures of in June and July. It would seem that the electronics are current model products.
FastSDD system
25mm Fast SDD - 500um - 0.5mm Be Window
PA230 - looks to be an early model of the PA230 Board - Red PCB vs. normal Green/Blue PCB with fewer parts
DP5X - looks to be a simpler integrated version of the DP5/PC5 board combo.
I've studied the pictures of the PA boards for which I could find pictures to see how they have evolved over time. I've seen about four different versions, which increase in complexity. But I'm not sure if this is a function of product development over time or that one board may be designed for SiPIN vs SDD.
Anyway, I wonder if anyone has some insight into the tradeoffs between the two complete systems mentioned SiPIN vs FastSDD. One has the obviously better detector (SDD). The other seems to have the better backend electronics (SiPIN) and is cheaper. I'd love to have anyone's expertise if figuring out which may be the better option.
BTW, if anyone is curious, here are some of the patents which seem to show the inner workings of some of the Amptek Systems:
US6,587,003B2 - Charge Sensitive Preamplifier with Pulsed Reset Source - the secret sauce in low noise preamplifiers, besides a good FET and OpAmp, is using a pulsed reset instead of a large drain resister, which adds noise. This approach is explained in Amptek's Reset Preamplifier Application Note.
US7448802 - Integrated X-Ray Source Module - The X-ray source that Amptek sells appears to be made by Newton Scientific - this is the schematic of the inner electronics which could be useful for someone trying to repair one of these units. The reference for U10 which is the main controller IC is conspicuously absent - but it looks to be the UC1872/2872/3872 made by Unitrode
US7949099 - Compact High Voltage X Ray Source - you can also look at how the tubes themselves are put together.
NOTE: These designs are still under patent protect so I would not recommend that someone actually build any of these - but they could be useful for repair.
" and a hardness (7) much greater than calcite indicates quartz."
?
What method used for hardness testing Dud?
Geo
?
From: "Ken Sejkora" <kjsejkora@...> To: [email protected], "DFEMER" <dfemer@...> Sent: Monday, November 30, 2020 9:50:41 AM Subject: Re: [XRF] Non Red Parking Lot "Calcite
?
Hi Dud,
?
Thanks for the very extensive analyses and interpretation of the results.? Your latest round of assessment validates our earlier assumption that the white matrix was actually comprised of two minerals, calcite and quartz/quartzite.? I really appreciate the other tests using reflectance, HCl effervescence, and hardness which confirms the quartz.
?
I haven¡¯t yet gotten over to the parking lots at night, but my wife and I took a walk yesterday afternoon and parked in one of the lots.? I spent about 20 minutes picking up many different pieces of the white material, but scrutinizing it more closely to look for the waxier calcite as opposed to the more fractured, angular quartz/quartzite.? Probably only about 10% of the pieces I collected and examined were calcite¡ the majority were quartzite, but several of the pieces contained some still well-formed quartz crystal faces offset by 120¡ã to each other.? Nothing huge, the biggest being maybe 0.4 cm long.
?
I did end up collecting about 20 specimens that appeared to be primarily calcite so I could get them into a darker environment for UV analysis.? I managed to score several pieces the exhibit the brightest fluorescence and phosphorescence I¡¯ve seen yet with the Convoy S2+ UV flashlight.? The best is roughly square, about 3 cm on the side, and about 1 cm thick.? Some very nice, flat-faced calcite crystals on it.? Another piece had been run over by a vehicle and consisted of about 8 or 9 fractured pieces around 0.5 to 1 cm in dimension, but showing some great fluorescence.?
?
You mentioned the strong response to the 405 nm laser.? I have also observed that.? I don¡¯t know much about the laser technology involved with the 405 nm lasers, but recall from an earlier email that you said it is not a pumped laser, like the green lasers that double the frequency of a strong but invisible IR wavelength to obtain the visible green.? Is there any UV component to the 405 nm laser¡¯s spectrum, or is the 405 nm wavelength in a ¡°sweet spot¡± sufficient to excite something in the calcite (Mn??) enough to elevate the electron energy to a level sufficient to yield a 610 nm red response (fluorescence) once the electron decays to its ground state?? I¡¯d appreciate any insights you have about what causes the red response to the 405 nm laser.
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Thanks again for the analyses, Dud.? You certainly expanded my understanding of what I¡¯m looking at.? Have a great holiday season.
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73? --? Ken, WB0OCV
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From: Dude Sent: Saturday, November 28, 2020 03:47 PM To: [email protected] Subject: [XRF] Non Red Parking Lot "Calcite
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Ken,
The second set of Non-Red ¡°calcite ¡° pieces you sent me are turned out to be quartz not calcite although they do look pretty much the same.
Attached are the XRF, optical, ?reflectance and assay runs on the parking lot Non Red ¡°calcite¡± pieces.
The optical spectra shows no red at ?610 nm ?(orange-red) like the last pieces sent, however under 365 and 405nm laser they show a weak whitish green fluorescence extending from 450 to 650 nm. ?
The Reflectance spectra have a 40% reflectance monotonically decreasing to 37% in the red to NIR. Again pretty much a white rock with no absorption centers.
The Assay was run with an Olympus DP4050 XRF in the Soil REE mode as we were looking for activators in the ppm range. That mode will over report % level elements.
None of the chips of ¡°Calcite¡± show any rare earths at the higher energies.
Three samples were run, a small chip , a large piece and the large piece on the dark section in it. The dark section showed strong Fe, Mn, Ca, Cu, Zn, Pb and Rb over the other shots
The valid elements detected in the quartz sections are Si, Ca, Mn, Fe, Sr, and weak Pb, Cu and Zn. The others are interferences from peak overlap and should be ignored.
The strong presence of Si (which I don¡¯t have an calibrate for), no effervescence under hydrochloric acid and a hardness (7) much greater than calcite indicates quartz.
Under a microscope the rock is composed of individual welded angular pieces indicating a metamorphic origin. This is a Quartzite not calcite. Quartzite is a very tough rock and is commonly used for parking lots and decorative fill. The original crystalline calcite probably occurred as veins intruding into the unit at some point in time.
Nick Andrews
