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Re: Wavelenght Dispersive Microanalysis
WDS is definitely on topic Steve, We welcome any and all threads concerning the practice. One of the things I do is service the Tel-X-Ometer unit, it is a sort of college level WDS and all around X-Ray demonstration unit. Not a microanalysis unit obviously. Lots of stuff we use in XRF is same as is used in SEM. The idea of using beta particle emitters to excite XRF came directly from the electron beam scanning microscope in material analysis mode. I usually use Kr-85 for that. It's a way we can excite things above the range of microfocus X-Ray tubes, and Am-241. Pb Ka, Kb is a breeze. Lots of info and even the full lab manual(experiments and demonstrations)? is in my 2020MANUALS section. I personally own several fully functional units, and several others, 8 in all at last count. Always promised myself to learn to use them for WDS, but it just hasn't come up yet.... Say Steve do you have the specifications or could get them for the fire tower used for Trinity? I'm particularly interested in the steel thickness and alloy used for the angle iron. Geo? ----- Original Message ----- From: WILLIAM S Dubyk <sdubyk@...> To: [email protected] Sent: Thu, 13 Feb 2020 23:11:14 -0500 (EST) Subject: [XRF] Wavelenght Dispersive Microanalysis I was talking to Mike Spilde at UNM about mineral analyses for some of the low Z elements like Be, since you can't do that with xrf. He gave me some information about how he does it with this WDS method. I thought it was pretty "Wow" so you may be interested in this, this has a real good explanation of how you can analyze these elements with a SEM. The d-spacings of the crystals he uses are 120, 90 and 60 angstroms to capture Be to F. I also thought it was pretty neat that proportional detectors are used for the analyses. Kind of off topic and a little out of this league but you gotta admit it's pretty cool. Steve? |
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Wavelenght Dispersive Microanalysis
I was talking to Mike Spilde at UNM about mineral analyses for some of the low Z elements like Be, since you can't do that with xrf. He gave me some information about how he does it with this WDS method. I thought it was pretty "Wow" so you may be interested in this, this has a real good explanation of how you can analyze these elements with a SEM. The d-spacings of the crystals he uses are 120, 90 and 60 angstroms to capture Be to F. I also thought it was pretty neat that proportional detectors are used for the analyses. Kind of off topic and a little out of this league but you gotta admit it's pretty cool.
Steve? |
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Re: Trinitite
Attached is a fresh .mca scan of the larger one of the 2 pieces of unusual Trinitite. This scan is of a surface, the earlier scan above (just a picture) was of an edge. The edge is most interesting looking and probably tells a story.
We have two know peaks to tweak calibration, 59.5 which I believe to be the daughter product of Pu-241 = Am-241. The Pu-241 has a half life of 14.4 years so has undergone 5+ half-lives, meaning it is barely still there. .Fortunately the Am-241 daughter lasts a lot longer. The next known peaks are from fission product Cs-137 = Ba-137m. m means metastable = fast decays, half life is 2.5 minutes.? Some thoughts- Where there is Cs-137, there is often Sr-90. We have a way to detect Sr-90 in the presence of Cs-137, they have similar half-lives. Where there is Pu-241 there are probably other Pu isotopes, the one I'm interested in proving is Pu-239. Fortunately it is long lasting, and some day 239 will be the only thing radioactive left in this sample. When I get confirmation from the group that this is indeed Trinitite, pictures will be posted. Geo>K0FF |
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Re: Trinitite
Concerning the 13-17 keV X-Rays in Trinitite.
When we detect Np- X-Rays, where do they come from? One way is from XRFing Neptunium element by adding energy to it. The other obvious way is by radioactive decay of Am-241. Normally a newly created nucleus radiates some energy after the transition to the new element as it settles into its most permanent state, some of which excites the inner electron shells of that same atom, causing a sort of auto-XRF effect. For neptunium it's the L lines of 13.944 and 17.75 that are of most interest to us, as well as the 20.785 keV Ly1 lines. Other radioactive decays can lead to Np-237-? they are Pu-237 U-237, neither of these are likely to be encountered in the amateur lab. When we see Uranium X-Rays, where do they come from? Well, there are a lot of uranium isotopes around, the natural ones that we see a lot are U-234, U235 and U-238. None of these produce U X-Rays when they decay, To my knowledge, we can only see U X-Rays is by deliberate or accidental XRF, and from the decay of Pa-234 and Pa-234m. Pa-234 and Pa-234m occur in the natural decay chain of U-238, by far the most abundant of the U isotopes in nature , both coming from Th-234, the immediate daughter of U-238.. Th-234 leads to Pa-234m at 100%, Being a metastable isotope (denoted by the small m after the numbers), this decays away rather quickly, 98.8% of the time directly to U-234, and giving us that unmistakable 1.001 MeV marker, while the other 0.2% it decays to Pa-234, which itself eventually decays to U-234. It is especially the L lines of uranium- La1- @13.61, [email protected] and Ly-1 @20.167 keV the newly created U-234 atom that gives us the auto-XRF. The Trinitite Tie-In Most Trinitite gives us the familiar 3-little-bears X-Rays down at the low end. Up until now they have remained a blur in the Home Rad Lab, really impossible to tell what is exactly going on there with sodium iodide probes. I think we now can and should try to determine which of those lines come from Pu-241 decay to Am-241 decay to Np-237, and? the direct decay of Pu-238/239/240 to uranium isotopes.? Geo>K0FF (corrections welcomed) |
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Re: Trinitite
Yep, that's the one and only I've found too. Pretty sure that was Jon R's work for Bill K-s book. Sure would like to see many more HPGe Trinititte scans, especially of matereril that is not sand. Geo ----- Original Message ----- From: WILLIAM S Dubyk <sdubyk@...> To: [email protected] Sent: Tue, 11 Feb 2020 17:29:20 -0500 (EST) Subject: Re: [XRF] Trinitite Pretty cool Geo. Attached is a part of the HP-Ge scan of trinitite in the Pittauerova paper, the peaks in grey are x-rays. Interesting.? Steve From: [email protected] <[email protected]> on behalf of GEOelectronics@... <GEOelectronics@...> Sent: Tuesday, February 11, 2020 1:17 PM To: [email protected] <[email protected]> Subject: Re: [XRF] Trinitite ? Ok this one IS Trinitite, but an unusual form, perhaps unique, I suspect this has no gadolinium, Si, Ki etc. but does have the usual plutonium daughters and Cs-137 fission fragments. Geo>K0FF |
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Re: Trinitite
¿ªÔÆÌåÓýSend the mca files with your pictures and a brief write up of the set up. Dud From: [email protected]
[mailto:[email protected]] On Behalf Of GEOelectronics@...
Sent: Tuesday, February 11, 2020 12:18 PM To: [email protected] Subject: Re: [XRF] Trinitite ? Ok this one IS Trinitite, but an unusual form, perhaps
unique, I suspect this has no gadolinium, Si, Ki etc. but does have the usual
plutonium daughters and Cs-137 fission fragments. |
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Re: Trinitite
¿ªÔÆÌåÓý
Pretty cool Geo. Attached is a part of the HP-Ge scan of trinitite in the Pittauerova paper, the peaks in grey are x-rays. Interesting.?
Steve
From: [email protected] <[email protected]> on behalf of GEOelectronics@... <GEOelectronics@...>
Sent: Tuesday, February 11, 2020 1:17 PM To: [email protected] <[email protected]> Subject: Re: [XRF] Trinitite ?
Ok this one IS Trinitite, but an unusual form, perhaps unique, I suspect this has no gadolinium, Si, Ki etc. but does have the usual plutonium daughters and Cs-137 fission fragments.
Geo>K0FF |
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Re: Brannerite! (or is it?)
Dud, Gunnar is in room 266 at this venue.? He has a lot of interesting stuff including petscheckite associated with columbite-Fe.? Perhaps you would have better luck understanding his mineral id methods.
Charles On Tue, Feb 11, 2020 at 11:12 AM <GEOelectronics@...> wrote:
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Re: Brannerite! (or is it?)
Thanks for the offer and for the sodium offer. I'll keep that in mind and appreciate. Right now I'm swamped with re-running all my present samples on the Si-PIN. Say Steve, do you know Bruze? Geo>K0FF ----- Original Message ----- From: WILLIAM S Dubyk <sdubyk@...> To: [email protected] Sent: Mon, 10 Feb 2020 22:48:01 -0500 (EST) Subject: Re: [XRF] Brannerite! (or is it?) If you need a chunk or monazite, let me know, I've got plenty of it. From: [email protected] <[email protected]> on behalf of GEOelectronics@... <GEOelectronics@...> Sent: Monday, February 10, 2020 8:25 PM To: [email protected] <[email protected]> Subject: Re: [XRF] Brannerite! (or is it?) ? Cool Steve. I don't follow the fine details but get the idea. We appreciate your input. George? ----- Original Message ----- From: WILLIAM S Dubyk <sdubyk@...> To: [email protected] Sent: Mon, 10 Feb 2020 21:58:52 -0500 (EST) Subject: Re: [XRF] Brannerite! (or is it?) You are correct Geo, those are not very accurate. Charles ran a specimen of xenotime from Madagascar that I had in my collection for years, a rather expensive one. It may have been from Madagascar so that part may be correct, but the x-ray indicated it was likely monazite. Not happy about that but oh well. Yes, lots of thorium in the US, probably mostly as monazite, the Ce-Th phosphate. Thorium is almost always in the +4 state, whereas U is commonly in the +4 and +6 state. That indicates that U can also form oxidized minerals, but Th does not. So Th minerals commonly contain U, and unoxidized primary U minerals also contain Th. When you get to the oxidized +6 U minerals however, they are very pure U with virtually no Th. So if you want a good pure U standard, get an oxidized U mineral like meta autunite or something.? Steve From: [email protected] <[email protected]> on behalf of GEOelectronics@... <GEOelectronics@...> Sent: Monday, February 10, 2020 9:31 AM To: [email protected] <[email protected]> Subject: Re: [XRF] Brannerite! (or is it?) ? haha. I've heard stories about the voracity of those rock-shop labels.? Hey mineral guys, a question. How common is thorium in USA? Does it always come with U or is it also alone? Thanks Geo>K0FF ----- Original Message ----- From: Charles David Young <charlesdavidyoung@...> To: [email protected], Mike Loughlin <loughlin3@...> Sent: Mon, 10 Feb 2020 07:33:50 -0500 (EST) Subject: [XRF] Brannerite! (or is it?) I picked this up yesterday.? It was interesting because Brannerite UTi2O6 is supposed to be high in Ti and less so in Ta and Nb like betafites (Ca,Na,U)2(Ti, Nb,Ta)2O6Z(OH).? However, this specimen has much more Nb than anything else.? It is going back to the dealer today with this scan so he can label it correctly. Charles |
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Re: Brannerite! (or is it?)
¿ªÔÆÌåÓýCharles, I can¡¯t tell if there is any Th there from the XRF. Run a gamma spec and see.? It¡¯s interesting that there is some Ba there which interferes with the Ti ? Where is he located I¡¯d like to pick up a piece and run it dud From: [email protected]
[mailto:[email protected]] On Behalf Of Charles David Young
Sent: Tuesday, February 11, 2020 7:58 AM To: [email protected] Subject: Re: [XRF] Brannerite! (or is it?) ? Sorry that I forgot to attach the .mca file.? Here it is. ? So I went back to the dealer today.? Gunnar Faerber is a highly experienced collector and has his own analysis equipment.? Unfortunately, between his heavy German accent and his very technical explanations I was somewhat lost as he was assuring me that this was definitely brannerite based on the latest definitions.? Also, mindat has the following for brannerite: ? UTi2O6 ? So Gunnar was not at all surprised to see the large amount of Nb.? He promised to send me his analysis so perhaps that will further enlighten.? In the meanwhile, I am going to assume that this is indeed brannerite.? BTW he said that betafite is an old discredited term and should not be used. ? Charles ? ? ? On Mon, Feb 10, 2020 at 8:48 PM WILLIAM S Dubyk <sdubyk@...> wrote:
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Re: Brannerite! (or is it?)
Late to the party, sorry, was Ti found? Geo ----- Original Message ----- From: Charles David Young <charlesdavidyoung@...> To: [email protected] Sent: Tue, 11 Feb 2020 10:57:59 -0500 (EST) Subject: Re: [XRF] Brannerite! (or is it?) Sorry that I forgot to attach the .mca file.? Here it is. So I went back to the dealer today.? Gunnar Faerber is a highly experienced collector and has his own analysis equipment.? Unfortunately, between his heavy German accent and his very technical explanations I was somewhat lost as he was assuring me that this was definitely brannerite based on the latest definitions.? Also, mindat has the following for brannerite: UTi2O6 Often contains impurities; an older formula is (U4+,REE,Th,Ca)(Ti,Fe3+,Nb)2(O,OH)6. So Gunnar was not at all surprised to see the large amount of Nb.? He promised to send me his analysis so perhaps that will further enlighten.? In the meanwhile, I am going to assume that this is indeed brannerite.? BTW he said that betafite is an old discredited term and should not be used. Charles On Mon, Feb 10, 2020 at 8:48 PM WILLIAM S Dubyk <sdubyk@...> wrote:
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Re: Brannerite! (or is it?)
Sorry that I forgot to attach the .mca file.? Here it is. So I went back to the dealer today.? Gunnar Faerber is a highly experienced collector and has his own analysis equipment.? Unfortunately, between his heavy German accent and his very technical explanations I was somewhat lost as he was assuring me that this was definitely brannerite based on the latest definitions.? Also, mindat has the following for brannerite: UTi2O6 Often contains impurities; an older formula is (U4+,REE,Th,Ca)(Ti,Fe3+,Nb)2(O,OH)6. So Gunnar was not at all surprised to see the large amount of Nb.? He promised to send me his analysis so perhaps that will further enlighten.? In the meanwhile, I am going to assume that this is indeed brannerite.? BTW he said that betafite is an old discredited term and should not be used. Charles
On Mon, Feb 10, 2020 at 8:48 PM WILLIAM S Dubyk <sdubyk@...> wrote:
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Re: Brannerite! (or is it?)
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> on behalf of GEOelectronics@... <GEOelectronics@...>
Sent: Monday, February 10, 2020 8:25 PM To: [email protected] <[email protected]> Subject: Re: [XRF] Brannerite! (or is it?) ?
Cool Steve. I don't follow the fine details but get the idea.
We appreciate your input.
George?
----- Original Message -----
From: WILLIAM S Dubyk <sdubyk@...> To: [email protected] Sent: Mon, 10 Feb 2020 21:58:52 -0500 (EST) Subject: Re: [XRF] Brannerite! (or is it?) You are correct Geo, those are not very accurate. Charles ran a specimen of xenotime from Madagascar that I had in my collection for years, a rather expensive one. It may have been from Madagascar so that part may be correct, but the x-ray indicated it was likely monazite. Not happy about that but oh well. Yes, lots of thorium in the US, probably mostly as monazite, the Ce-Th phosphate. Thorium is almost always in the +4 state, whereas U is commonly in the +4 and +6 state. That indicates that U can also form oxidized minerals, but Th does not. So Th minerals commonly contain U, and unoxidized primary U minerals also contain Th. When you get to the oxidized +6 U minerals however, they are very pure U with virtually no Th. So if you want a good pure U standard, get an oxidized U mineral like meta autunite or something.? Steve From: [email protected] <[email protected]> on behalf of GEOelectronics@... <GEOelectronics@...>
Sent: Monday, February 10, 2020 9:31 AM To: [email protected] <[email protected]> Subject: Re: [XRF] Brannerite! (or is it?) ?
haha. I've heard stories about the voracity of those rock-shop labels.?
Hey mineral guys, a question. How common is thorium in USA? Does it always come with U or is it also alone? Thanks
Geo>K0FF
----- Original Message -----
From: Charles David Young <charlesdavidyoung@...> To: [email protected], Mike Loughlin <loughlin3@...> Sent: Mon, 10 Feb 2020 07:33:50 -0500 (EST) Subject: [XRF] Brannerite! (or is it?) I picked this up yesterday.? It was interesting because Brannerite
UTi2O6
is supposed to be high in Ti and less so in Ta and Nb like betafites (Ca,Na,U)2(Ti, Nb,Ta)2O6Z(OH).? However, this specimen has much more Nb than anything else.? It is going back to the dealer today with this scan so he can label it correctly. Charles
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Re: Brannerite! (or is it?)
Cool Steve. I don't follow the fine details but get the idea. We appreciate your input. George? ----- Original Message ----- From: WILLIAM S Dubyk <sdubyk@...> To: [email protected] Sent: Mon, 10 Feb 2020 21:58:52 -0500 (EST) Subject: Re: [XRF] Brannerite! (or is it?) You are correct Geo, those are not very accurate. Charles ran a specimen of xenotime from Madagascar that I had in my collection for years, a rather expensive one. It may have been from Madagascar so that part may be correct, but the x-ray indicated it was likely monazite. Not happy about that but oh well. Yes, lots of thorium in the US, probably mostly as monazite, the Ce-Th phosphate. Thorium is almost always in the +4 state, whereas U is commonly in the +4 and +6 state. That indicates that U can also form oxidized minerals, but Th does not. So Th minerals commonly contain U, and unoxidized primary U minerals also contain Th. When you get to the oxidized +6 U minerals however, they are very pure U with virtually no Th. So if you want a good pure U standard, get an oxidized U mineral like meta autunite or something.? Steve From: [email protected] <[email protected]> on behalf of GEOelectronics@... <GEOelectronics@...> Sent: Monday, February 10, 2020 9:31 AM To: [email protected] <[email protected]> Subject: Re: [XRF] Brannerite! (or is it?) ? haha. I've heard stories about the voracity of those rock-shop labels.? Hey mineral guys, a question. How common is thorium in USA? Does it always come with U or is it also alone? Thanks Geo>K0FF ----- Original Message ----- From: Charles David Young <charlesdavidyoung@...> To: [email protected], Mike Loughlin <loughlin3@...> Sent: Mon, 10 Feb 2020 07:33:50 -0500 (EST) Subject: [XRF] Brannerite! (or is it?) I picked this up yesterday.? It was interesting because Brannerite UTi2O6 is supposed to be high in Ti and less so in Ta and Nb like betafites (Ca,Na,U)2(Ti, Nb,Ta)2O6Z(OH).? However, this specimen has much more Nb than anything else.? It is going back to the dealer today with this scan so he can label it correctly. Charles |
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Re: Brannerite! (or is it?)
¿ªÔÆÌåÓý
You are correct Geo, those are not very accurate. Charles ran a specimen of xenotime from Madagascar that I had in my collection for years, a rather expensive one. It may have been from Madagascar so that part may be correct, but the x-ray indicated it
was likely monazite. Not happy about that but oh well. Yes, lots of thorium in the US, probably mostly as monazite, the Ce-Th phosphate. Thorium is almost always in the +4 state, whereas U is commonly in the +4 and +6 state. That indicates that U can also
form oxidized minerals, but Th does not. So Th minerals commonly contain U, and unoxidized primary U minerals also contain Th. When you get to the oxidized +6 U minerals however, they are very pure U with virtually no Th. So if you want a good pure U standard,
get an oxidized U mineral like meta autunite or something.?
Steve
From: [email protected] <[email protected]> on behalf of GEOelectronics@... <GEOelectronics@...>
Sent: Monday, February 10, 2020 9:31 AM To: [email protected] <[email protected]> Subject: Re: [XRF] Brannerite! (or is it?) ?
haha. I've heard stories about the voracity of those rock-shop labels.?
Hey mineral guys, a question. How common is thorium in USA? Does it always come with U or is it also alone? Thanks
Geo>K0FF
----- Original Message -----
From: Charles David Young <charlesdavidyoung@...> To: [email protected], Mike Loughlin <loughlin3@...> Sent: Mon, 10 Feb 2020 07:33:50 -0500 (EST) Subject: [XRF] Brannerite! (or is it?) I picked this up yesterday.? It was interesting because Brannerite
UTi2O6
is supposed to be high in Ti and less so in Ta and Nb like betafites (Ca,Na,U)2(Ti, Nb,Ta)2O6Z(OH).? However, this specimen has much more Nb than anything else.? It is going back to the dealer today with this scan so he can label it correctly.
Charles
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