Probe Software Users Forum
Software => CalcZAF and Standard => Topic started by: Ben Buse on March 07, 2017, 07:15:03 AM
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Hi,
Does anyone know of a paper that compares Armstrong matrix correction with PAP and XPHI. In Pouchou & Pichoir (1991) (Heinrich green book) - we have 826 dataset - and is tested on following
(https://probesoftware.com/smf/gallery/453_07_03_17_7_10_06.png)
and Merlet (1994) tried his XPHI model
(https://probesoftware.com/smf/gallery/453_07_03_17_7_11_04.png)
But none compare Armstrong
I notice in Calczaf you can do histogram using Pouchouz10 - but this has 91 analyses - what is this?
I'm guessing Armstrong is good for geological samples - as it was developed and tested for them Armstrong (1988) but maybe not as good across the whole range??
Is it possible to change the default matrix correction in PFE.
Thanks
Ben
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Following on from my post.
I see you can calculate binaries for pouchouz10 - does this correspond to the 577 analyses z dominant?
pouchouza20 - does this correspond to the 242 analyses absorption dominant.
I've tried pouchou.dat this has 756 analyses how does this compare to 826 analyses of Pouchou & Pichoir (1991)
and pouchouz2.dat - I just tried this is the 826 dataset
Thanks
Ben
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Right so here is Armstrong and FFAST
(https://probesoftware.com/smf/gallery/453_07_03_17_9_25_51.png)
And here is PAP and FFAST
(https://probesoftware.com/smf/gallery/453_07_03_17_9_30_14.png)
And PAP with MAC30 - as in table
(https://probesoftware.com/smf/gallery/453_07_03_17_9_39_26.png)
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Does anyone know of a paper that compares Armstrong matrix correction with PAP and XPHI. In Pouchou & Pichoir (1991) (Heinrich green book) - we have 826 dataset - and is tested on following
and Merlet (1994) tried his XPHI model
But none compare Armstrong
I notice in calczaf you can do histogram using Pouchouz10 - but this has 91 analyses - what is this?
I'm guessing Armstrong is good for geological samples - as it was developed and tested for them Armstrong (1988) but maybe not as good across the whole range??
Hi Ben,
I see Owen answered your question on changing the default correction in PFE and CalcZAF from the probewin.ini file.
Paul Carpenter can provide the exact details but here is what I remember: the Armstrong phi/rho/z was only published in this paper:
Armstrong, J. T. "Quantitative analysis of silicate and oxide minerals: a reevaluation of ZAF corrections and proposal for new Bence-Albee coefficients." Microbeam Analysis 19 (1984): 208-212.
but it was just a tweak of two existing corrections (Brown and another I think), where John Armstrong noticed that with his silicate (Shaw) k-ratio dataset (see shaw.dat attached below), he found that one phi/rho/z gave slightly "high" results and another gave slightly "low" results, and then he noticed that the only difference between the two corrections was an exponent in one term. So Armstrong "split the difference" with the two exponent values and got good results, at least with his shaw k-ratio data set.
Now you should be careful using any correction method which was "tuned" to a particular dataset, and that goes for the Pouchou k-ratio dataset as well. Because Pouchou tuned the XPP and PAP corrections to the Pouchou dataset, (using the Bastin MAcs) you will always get the best results on the Pouchou dataset using the XPP or PAP corrections.
Best to try several different datasets, see attached below. The Pouchou.dat dataset is the original dataset I got from Armstrong many years ago. The Pouchou2.dat dataset is an "extended" version I got from Philippe Pinard and Hendrix Demers. The POUCHOU2_wo_B_wo_Cu_La.DAT dataset is the Pouchou2.dat dataset *without* the boron and Cu L k-ratios which are affected by chemical shifts.
john
PS Yes, the Pouchouz10.dat dataset is a subset of the Pouchou dataset where the atomic number correction (Z) is greater than 10%. These types of subset output can be generated in CalcZAF using the filter options in the Analytical | Binary Calculations Options menu dialog as shown here:
(https://probesoftware.com/smf/gallery/395_07_03_17_11_22_48.png)
The NISTBIN and Pouchou.dat datasets should be included with the normal CalcZAF installation, but maybe not the new Pouchou2.dat.
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Thanks Owen and John,
That's a great help. So I guess not using Bastin MAC's explains the slight discrepancy from the published table.
Ben
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So I guess not using Bastin MAC's explains the slight discrepancy from the published table.
Yes. But I don't have these Bastin MACs, so if anyone does I'd be interested in adding them as a table in CalcZAF.
john
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So I've just been looking up the references,
And NISTBIN contains:
(1) the Au-Cu and Au-Ag alloys of Kurt F. J. Heinrich and Harvey Yakowitz "Absorption of Primary X Rays in Electron Probe Microanalysis"
(2) Mg-Al alloys of J. I. GOLDSTEIN F. J. MAJESKE H. YAKOWITZ PREPARATION OF ELECTRON PROBE MICROANALYZER STANDARDS USING A RAPID QUENCH METHOD
(3) some other stuff. - Including Boron.
Thanks John, I've just downloaded the Shaw file - I guess this corresponds to
Shaw, H.F. & Albee, A.L. (1979)
An empirical investigation into possible nonlinearities of the microprobe correction factors in the system MgO-CaO-Al2O3-SiO2. In: Microbeam Analysis - 1979, Newbury, D.E. (ed), San Francisco Press, San Francisco, 227 - 230.
John - just a question about Shaw.dat - this is a regular input file for calczaf - so I process the regular way (Open input data and calculate and export all) - what are standards 2112,2113,2114,2120 - are these pure metals? Also when I quantify them what are the correct values.
Thanks
Ben
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So I guess not using Bastin MAC's explains the slight discrepancy from the published table.
Yes. But I don't have these Bastin MACs, so if anyone does I'd be interested in adding them as a table in CalcZAF.
john
The tables of MACs that Pouchou and Pichoir used in place of the Heinrich MAC30 MACs are located on p. 63 of EPQ, or on p. 33 of the attached pdf.
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So I guess not using Bastin MAC's explains the slight discrepancy from the published table.
Yes. But I don't have these Bastin MACs, so if anyone does I'd be interested in adding them as a table in CalcZAF.
john
The tables of MACs that Pouchou and Pichoir used in place of the Heinrich MAC30 MACs are located on p. 63 of EPQ, or on p. 33 of the attached pdf.
Hi Brian,
Thanks, but I should have been clearer. Yes, I knew they are in the "green book", but I was hoping to find a *digital* version of them!
Does anyone have that?
john
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Thanks John, I've just downloaded the Shaw file - I guess this corresponds to
Shaw, H.F. & Albee, A.L. (1979)
An empirical investigation into possible nonlinearities of the microprobe correction factors in the system MgO-CaO-Al2O3-SiO2. In: Microbeam Analysis - 1979, Newbury, D.E. (ed), San Francisco Press, San Francisco, 227 - 230.
John - just a question about Shaw.dat - this is a regular input file for calczaf - so I process the regular way (Open input data and calculate and export all) - what are standards 2112,2113,2114,2120 - are these pure metals? Also when I quantify them what are the correct values.
Hi Ben,
Sorry I should have explained better. The standards are simply the pure oxides, MgO, Al2O3, SiO2 and CaO. Not sure how they measured a pure CaO standard!
I've attached my current standard.mdb file which has them listed. Note: previous version of this database had them listed as pure metals, this was incorrect. They are pure oxides.
john
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So I guess not using Bastin MAC's explains the slight discrepancy from the published table.
Yes. But I don't have these Bastin MACs, so if anyone does I'd be interested in adding them as a table in CalcZAF.
john
The tables of MACs that Pouchou and Pichoir used in place of the Heinrich MAC30 MACs are located on p. 63 of EPQ, or on p. 33 of the attached pdf.
Hi Brian,
Thanks, but I should have been clearer. Yes, I knew they are in the "green book", but I was hoping to find a *digital* version of them!
Does anyone have that?
john
Hi John and Ben,
I've attached a text file with the MACs that Pouchou and Pichoir used for X-rays of the light elements; it should be entirely consistent with their paper in EPQ.
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So I guess not using Bastin MAC's explains the slight discrepancy from the published table.
Yes. But I don't have these Bastin MACs, so if anyone does I'd be interested in adding them as a table in CalcZAF.
john
The tables of MACs that Pouchou and Pichoir used in place of the Heinrich MAC30 MACs are located on p. 63 of EPQ, or on p. 33 of the attached pdf.
Hi Brian,
Thanks, but I should have been clearer. Yes, I knew they are in the "green book", but I was hoping to find a *digital* version of them!
Does anyone have that?
john
Hi John and Ben,
I've attached a text file with the MACs that Pouchou and Pichoir used for X-rays of the light elements; it should be entirely consistent with their paper in EPQ.
Hi Brian,
That's very nice and useful, thanks. I have essentially the same table already in the EMPMAC.DAT file that is distributed with CalcZAF (since these are empirical measurements from multiple keVs fitted using his XMAC code I believe). For example:
"b" "ka" "b" 3400 "Bastin (1992)"
"b" "ka" "b" 3500 "Pouchou (1998)"
"b" "ka" "b" 3068 "Donovan (2011)"
"b" "ka" "c" 6500 "Bastin (1992)"
"b" "ka" "n" 11200 "Bastin (1992)"
"b" "ka" "n" 11000 "Pouchou (1998)"
"b" "ka" "n" 10421 "Donovan (2011)"
"b" "ka" "mg" 59500 "Pouchou (1998)"
"b" "ka" "mg" 54500 "Donovan (2011)"
"b" "ka" "al" 64000 "Bastin (1992)"
"b" "ka" "si" 84000 "Bastin (1992)"
"b" "ka" "ti" 14700 "Bastin (1992)"
"b" "ka" "v" 17700 "Bastin (1992)"
"b" "ka" "cr" 20200 "Bastin (1992)"
"b" "ka" "fe" 27300 "Bastin (1992)"
"b" "ka" "co" 33400 "Bastin (1992)"
"b" "ka" "ni" 42000 "Bastin (1992)"
"b" "ka" "zr" 4000 "Bastin (1992)"
"b" "ka" "nb" 4600 "Bastin (1992)"
"b" "ka" "mo" 4550 "Bastin (1992)"
"b" "ka" "la" 2500 "Bastin (1992)"
"b" "ka" "ta" 22500 "Bastin (1992)"
"b" "ka" "w" 21400 "Bastin (1992)"
"b" "ka" "u" 8200 "Bastin (1992)"
"b" "ka" "b" 3471 "Pouchou (1992)"
"b" "ka" "c" 6750 "Pouchou (1992)"
"b" "ka" "n" 11000 "Pouchou (1992)"
"b" "ka" "o" 16500 "Pouchou (1992)"
"b" "ka" "al" 64000 "Pouchou (1992)"
"b" "ka" "si" 80000 "Pouchou (1992)"
"b" "ka" "ti" 15000 "Pouchou (1992)"
"b" "ka" "v" 18000 "Pouchou (1992)"
"b" "ka" "cr" 20700 "Pouchou (1992)"
"b" "ka" "fe" 27800 "Pouchou (1992)"
"b" "ka" "co" 32000 "Pouchou (1992)"
"b" "ka" "ni" 37000 "Pouchou (1992)"
"b" "ka" "zr" 4400 "Pouchou (1992)"
"b" "ka" "nb" 4500 "Pouchou (1992)"
"b" "ka" "mo" 4600 "Pouchou (1992)"
"b" "ka" "la" 2500 "Pouchou (1992)"
"b" "ka" "ta" 23000 "Pouchou (1992)"
"b" "ka" "w" 21000 "Pouchou (1992)"
"b" "ka" "u" 7400 "Pouchou (1992)"
Too bad your file (and mine) doesn't include all the MACs for all the emitters in the Pouchou k-ratio database (e.g., Au La, Ma, etc.). I think Ben was hoping to use the same MACs that Pouchou used for "tuning" the PAP correction to all the measured k-ratios in the Pouchou2.dat database. I guess Ben was hoping to try and reproduce the error distributions Pouchou originally published...
john
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Too bad your file (and mine) doesn't include all the MACs for all the emitters in the Pouchou k-ratio database (e.g., Au La, Ma, etc.). I think Ben was hoping to use the same MACs that Pouchou used for "tuning" the PAP correction to all the measured k-ratios in the Pouchou2.dat database. I guess Ben was hoping to try and reproduce the error distributions Pouchou originally published...
john
OK, I see what you mean. I approach it somewhat differently in that I calculate MACs as needed from Heinrich's equations (or by polynomial interpolation when using the FFAST or CXRO models) and then substitute values from tables as required. So I don't have a convenient table at hand that contains all MAC values used by P&P for processing their database. I misunderstood what you were looking for.
However, even with such a table, it might still not be possible to reproduce the results of P&P exactly in CalcZAF. In their paper in EPQ, they imply that they used the characteristic fluorescence correction of Reed (1965). Although secondary fluorescence effects are small in the binary systems contained in their database, they're not necessarily negligible. I haven't programmed Reed's early model, and so I'm not sure to what extent discrepancies in my results versus those presented by P&P are due to this or to some other inconsistency (since they don't give calculated k-ratios line-by-line in Appendix 6).
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Too bad your file (and mine) doesn't include all the MACs for all the emitters in the Pouchou k-ratio database (e.g., Au La, Ma, etc.). I think Ben was hoping to use the same MACs that Pouchou used for "tuning" the PAP correction to all the measured k-ratios in the Pouchou2.dat database. I guess Ben was hoping to try and reproduce the error distributions Pouchou originally published...
john
OK, I see what you mean. I approach it somewhat differently in that I calculate MACs as needed from Heinrich's equations (or by polynomial interpolation when using the FFAST or CXRO models) and then substitute values from tables as required. So I don't have a convenient table at hand that contains all MAC values used by P&P for processing their database. I misunderstood what you were looking for.
However, even with such a table, it might still not be possible to reproduce the results of P&P exactly in CalcZAF. In their paper in EPQ, they imply that they used the characteristic fluorescence correction of Reed (1965). Although secondary fluorescence effects are small in the binary systems contained in their database, they're not necessarily negligible. I haven't programmed Reed's early model, and so I'm not sure to what extent discrepancies in my results versus those presented by P&P are due to this or to some other inconsistency (since they don't give calculated k-ratios line-by-line in Appendix 6).
Hi Brian,
I use a similar approach in CalcZAF. One can choose one of 5 different MAC table sources and then load selected MACs as deemed necessary from the EMPMAC.DAT file. Important for quantifying low energy emissions as you know.
Anyway, it's no big deal, I was just trying to help Ben out. But if such a "Pouchou" MAC table was available, I would add it to the CalcZAF distribution. Just for fun!
john
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Hi John and Brian,
Thank you for your replies, that's very interesting - I was curious as two why they did not agree -and you've answered my question. I guess it be possible to modify the MAC30 table with the values from Appendix 5 of green book -but I'm not sure its worth it - plus as Brian says there's difference in fluorescence correction.
As a related question - does the Cameca SX100 PAP routinue use the MAC's as specified by Pouchou and Pichoir - and Reed 1965 fluorescence correction - if so that would explain why the calczaf results never quite match the Cameca software results. I've never been able to find in the Cameca documentation which MAC's they use.
Thanks
Ben
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Hi John,
Thanks using your standard.mdb shaw data is working.
The compositions are given in Table 1 of Shaw & Albee 1979? Is that right?
Corresponding as follows
Sample 5 = Kyanite
Sample 6 = wollastonite
Sample 7 = anorthite
Sample 8 = Pyrope
Sample 9 = Grossularite
Sample 10 = Spinel
Sample 11 = Forsterite
Sample 12 = Diopside
Sample 13 = Enstatite
Sample 14 = Enal-20 Glass
Sample 15 = Enal-10 Glass
Sample 16 = Enal-5 Glass
Sample 17 = Glass P-721
Sample 18 = Glass P-722
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Thank you for your replies, that's very interesting - I was curious as two why they did not agree -and you've answered my question. I guess it be possible to modify the MAC30 table with the values from Appendix 5 of green book -but I'm not sure its worth it - plus as Brian says there's difference in fluorescence correction.
As a related question - does the Cameca SX100 PAP routinue use the MAC's as specified by Pouchou and Pichoir - and Reed 1965 fluorescence correction - if so that would explain why the calczaf results never quite match the Cameca software results. I've never been able to find in the Cameca documentation which MAC's they use.
Hi Ben,
Yes, as Brian points out, the compositions in the Pouchou database were selected to minimize fluorescence effects. So the selection of the fluorescence correction shouldn't make too much of a difference. They were mostly interested in the absorption/atomic number corrections (the ZA in the ZAF!). As you know, phi/rho/z methods basically combine the absorption and atomic number effects.
That said, I believe that if you turn off the M-line and beta fluorescence flags in our free CalcZAF utility as found in this dialog:
(https://probesoftware.com/smf/gallery/395_09_03_17_10_16_00.png)
you will get pretty close to the original Pouchou published results. It's worth a try...
john
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I've run the shaw.dat data - where did the k-ratios come from - did you do the analysis John?.
(https://probesoftware.com/smf/gallery/453_13_03_17_11_19_01.png)
Also is there an editable version of MAC30 (mac30.dat does not open in text editor), if I get time sometime I might make the PAP amendments - but won't be for awhile.
Ben
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I've run the shaw.dat data - where did the k-ratios come from - did you do the analysis John?.
Hi Ben,
No I did not.
I believe someone named "Shaw" did these at Cal Tech in the 1970s. I'm not that old! ;D I think John Armstrong or Paul Carpenter would know.
Also is there an editable version of MAC30 (mac30.dat does not open in text editor), if I get time sometime I might make the PAP amendments - but won't be for awhile.
Yes, it's a binary file, but you can edit the MAC30.dat file using CalcZAF. But even better would be to create your own "user defined" MAC table which you can edit to your heart's content.
Just use the X-Ray menu in CalcZAF and select the Create Default User Defined MAC Table menu. It will ask what existing MAC table you want to use as the basis, and you can select MAC30.DAT, and it will then copy it to the name USERMAC.DAT, which you can then edit as much as you want. This USERMAC.DAT can then be selected in the matrix correction options when you want to test it.
john
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Thanks John for the clear explanation of how to do it - I'll give it a go when I get a chance
Ben
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I've run the shaw.dat data - where did the k-ratios come from - did you do the analysis John?.
Hi Ben,
Paul Carpenter wrote me and mentioned "I don't have many details about the Shaw data, it was collected I am pretty sure on the MAC probe before the Jeol 733 at Caltech. I think maybe it is time for users to generate k-ratio data from the current suite of standards and go from there. This is what I do."
I would agree with Paul here. I can't remember what you originally wanted the Shaw dataset for, but it is pretty sparse. This reminds me that I'm hoping some bright young person will start a new k-ratio measurement set to further test our Monte Carlo simulation models, but this time include strongly fluorescing systems also (in addition to strong absorption and atomic number effects).
That was the goal of my "XTREME" (X-ray Table of Ratios with Exceptional Matrix Effects) proposal described here:
http://probesoftware.com/smf/index.php?topic=115.msg426#msg426
john
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Hi John,
Thanks using your standard.mdb shaw data is working.
The compositions are given in Table 1 of Shaw & Albee 1979? Is that right?
Corresponding as follows
Sample 5 = Kyanite
Sample 6 = wollastonite
Sample 7 = anorthite
Sample 8 = Pyrope
Sample 9 = Grossularite
Sample 10 = Spinel
Sample 11 = Forsterite
Sample 12 = Diopside
Sample 13 = Enstatite
Sample 14 = Enal-20 Glass
Sample 15 = Enal-10 Glass
Sample 16 = Enal-5 Glass
Sample 17 = Glass P-721
Sample 18 = Glass P-722
Hi Ben,
So I edited the Shaw.dat file to show the sample names you have listed above (see attached below). There are quite a few more compositions in the file, so I wonder if Paul Carpenter knows what the rest of these compositions are?
john
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Hi John,
Sorry I didn't mention - I had the names and ideal compositions from the paper (but the paper does not include the k-ratios - in the shaw.dat file). From the ideal compositions I calculated the difference to the compositions given by the Armstrong and PAP matrix corrections.
The other names are here:
Un1-4. Are the standards MgO, Al2O3, SiO2 and CaO
Un19-Un26 Are glasses P723 to P730
Un27 Cal-Al Pyroxene
And the excel file - of matrix corrections compared is attached. It includes the compositions given in the paper
Ben
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Hi Ben,
Thank-you.
I edited the CalcZAF shaw.dat input file for the proper sample names and I also extracted the "published" compositions from your spreadsheet into a file called shaw.csv, but with the samples listed in the same order as the shaw.dat input file. See attached below (remember everyone, you need to be logged in to see attachments).
john
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I have spent a fair bit of time on this project. The problem with measuring alpha factors is that, for example, in the MgO - Al2O3 binary, there is only one stoichiometric phase MgAl2O4 that defines the midpoint. So there is one measurement only on spinel for Mg and Al relative to MgO and Al2O3 standards. The precision of the measurement has to be very high and when you propagate errors and show the error bars on an alpha factor plot, you realize that there is no justification for using a formulation higher than linear (not constant, not polynomial). Similar problem in other binaries. In MgO - SiO2 there are forsterite and enstatite, but this is the exception. The authors came to this conclusion as well in their search for nonlinearity in the core CMAS system.
Clearly there is a basis for a polynomial formulation when using ZAF prz algorithms where you calculate factors at arbitrarily fine spaced increments of concentration, but that is not the point here.
Secondly. These measurements were made either on an ARL or the MAC probe and are subject to discussion regarding the instrumental stability in the case of the ARL (and takeoff angle not directly comparable to all other measurements made at 40 deg), and in the case of the MAC, non-normal beam incidence. When I was at Caltech I attempted to reconstruct the entire Bence Albee methodology from standards used for measurements and computer output of results. You have to understand that use of these standards predates BSE imaging. The fayalite standard used when I arrived had comments "avoid orange luminescent areas" which were quartz; the fayalite they were using historically was a synthetic material with coprecipitated quartz. The enstatite - Al graduated glasses are of unknown origin and pedigree but are clearly synthetic as well; I could only find two of the three glasses and basically no material left for futher use. Most MgO contains some amount of Ca and so is not pure, strictly speaking, and I doubt that was taken into consideration. There was not a standard mount that had all the standards for the study (so this means that multiple mounts having different carbon coats were used...). This is not to downplay the work that was done, but you have to keep these things in mind.
After the original and only measured alpha factors obtained at 52.5 deg on the ARL were published, they were superseded by the calculated values listed in the Albee Ray paper (and 40 degree factors appeared as well). From there on all factors were calculated by running ZAF in reverse. The desire to analyze S, Cl, etc. motivates a return to a-factors relative to pure element references, i.e., Ziebold Ogilvie, and again does not accomplish much relative to ZAF codes available today.
The real reason for development of BA alpha factors was to eliminate disagreement of ZAF results obtained on the Apollo 11 samples being analyzed by numerous labs, and also to have a small executable program that fit into microcomputers of the day. A BA correction on a Tracor TN2000 took about 1 minute whereas a ZAF correction took about 20 minutes (for an 8 element sample).
Going forward I think we have the same limitations unless one resorts to glasses which could in principle have any intermediate composition in a binary, but are probably goind to exhibit non-binary compositions (ie. a Fe-Si oxide glass could have ferric iron and iron loss to the Pt loop, etc.). The real utility of an alpha factor method is twofold: for graphical comparision of correction magnitude, and for processing X-ray maps (coupled with MAN background method).
I think the method I use is better and that is to compare the measured k-ratio for an element to that calculated by using CalcZAF. A value of kmeas / kcalc = 1 confirms the analytical measurement and all that it depends on (alignment, PHA and deadtime linearity, sample conductivity, etc.) and the correction algorithm (standard composition, algorithm, macs, etc.). Comparison of this measurement as a function of concentration for that element reveals any systematic errors and confirms the internal consistency of the standards used. This goes far beyond the evaluation within a binary join, and also reveals problems with the minor and trace element concentrations being used for microanalysis standards. This unbiased test is really the way to move forward.
Cheers,
Paul
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Hi Paul,
Thank-you for the historical context and other comments. This is interesting stuff.
To be honest, I'm not sure why Ben was looking at the Shaw data set, but I don't think he was looking at alpha factors as he only mentioned the PAP and Armstrong phi/rho/z methods in his previous posts. In any event, I figure it's good to get the Shaw dataset into CalcZAF with the proper samples names and published compositions. If only for purposes of historical documentation!
I agree with your suggestion about using CalcZAF to calculate errors from experimental measurements. Right now we just have the Pouchou and NIST datasets and they are selected for minimum fluorescence effects and are only binary compounds. More troubling is that these datasets were measured many years ago (though not as long ago as the Shaw dataset!), so I have to wonder of we should be working on a new experimental dataset of both binary and ternary compositions as I proposed here a while back:
http://probesoftware.com/smf/index.php?topic=115.msg426#msg426
There are a large number of synthetic single crystal materials now commercially available which I suspect we might be able to assume are stoichiometric with fairly high confidence of accuracy, and with these materials perhaps we can start looking more closely at, for example, highly fluorescing systems. And there's still some issues with very large atomic number corrections, e.g., Si Ka in PbSiO3 as just one example.
Karsten and I have looked a little at doing this, but I think a more community based effort might be worth while, even if it were only to obtain some of these new commercially made single crystal materials for round robin measurement of k-ratios under different keV conditions.
john
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Compositions for En-Al glasses:
St 274 Enstatite 80 Al2O3 20, syn glass, P-405
Syn Schairer, Boyd
Oxide and Elemental Composition
Average Total Oxygen: 47.664 Average Total Weight%: 100.000
Average Calculated Oxygen: 47.664 Average Atomic Number: 10.647
Average Excess Oxygen: .000 Average Atomic Weight: 20.140
ELEM: MgO Al2O3 SiO2 O
XRAY: ka ka ka ka
OXWT: 32.130 20.000 47.870 .000
ELWT: 19.375 10.585 22.376 47.664
KFAC: .1441 .0716 .1623 .2540
ZCOR: 1.3443 1.4789 1.3791 1.8769
AT% : 16.055 7.901 16.046 59.998
24 O: 6.422 3.161 6.418 24.000
St 275 Enstatite 90 Al2O3 10, syn glass, P-406
syn Schairer, Boyd
Oxide and Elemental Composition
Average Total Oxygen: 47.738 Average Total Weight%: 99.999
Average Calculated Oxygen: 47.738 Average Atomic Number: 10.647
Average Excess Oxygen: .000 Average Atomic Weight: 20.109
ELEM: MgO Al2O3 SiO2 O
XRAY: ka ka ka ka
OXWT: 36.139 9.999 53.860 .000
ELWT: 21.793 5.292 25.176 47.738
KFAC: .1616 .0350 .1864 .2543
ZCOR: 1.3489 1.5126 1.3505 1.8769
AT% : 18.031 3.944 18.026 59.999
24 O: 7.213 1.578 7.210 24.000
St 276 Enstatite 95 Al2O3 5, syn glass, P-407
Syn Schairer, Boyd
Weighed in values (oxide): Mg 38.16 Al 5 Si 56.84
This analysis CIT probe 1997
Oxide and Elemental Composition
Average Total Oxygen: 47.641 Average Total Weight%: 99.724
Average Calculated Oxygen: 47.640 Average Atomic Number: 10.661
Average Excess Oxygen: .001 Average Atomic Weight: 20.105
ELEM: Na2O MgO Al2O3 SiO2 CaO FeO O
XRAY: ka ka ka ka ka ka ka
OXWT: .094 37.551 4.930 56.969 .140 .040 .001
ELWT: .070 22.644 2.609 26.629 .100 .031 47.641
KFAC: .0004 .1673 .0171 .1996 .0009 .0003 .2529
ZCOR: 1.7065 1.3534 1.5266 1.3343 1.1130 1.2023 1.8834
AT% : .061 18.783 1.949 19.115 .050 .011 60.030
24 O: .025 7.509 .779 7.642 .020 .004 24.000
The analysis I made on En95-Al5 again points to small amounts of other elements in some of these standards.
Paul
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More questions:
Does anyone know how these glasses in the shaw.dat file were characterized for their "published" compositions? Wet chemistry?
Also, does anyone know if these glasses are still available? They might be the start of a new ternary (or more) element (XTREME) database with new measurements using new instruments...
john
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The glasses in the Shaw data set with P numbers are almost certainly the Weill (Peggy Dalheim) synthetic glasses in the CMAS compositional system (this means CaO-MgO-Al2O3-SiO2). The P numbers are Caltech standard numbers. The intention was to use them for calorimetric measurements and because accurate composition and homogeneity were important (and a hallmark of Weill's methodology), they are good reference materials. These glasses have been distributed in the past with informal names like "UO Weill glass A" etc.
Thanks for reminding me about the MAC takeoff angle of 38.5 degrees. ARL did not mfg. the MAC probe. I think it stands for Materials Analysis Corporation.
Cheers,
Paul
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Hi Paul,
Interesting. So these are the same glasses I found about 10 years ago in the old Weill lab and sent to you?
If so we already have some measurements at 40 degrees takeoff I did on my SX100 instrument some time ago. See attached MDB file... and here is glass "A" calculated using 10 different matrix corrections in Probe for EPMA:
Summary of All Calculated (averaged) Matrix Corrections:
St 2101 Set 2 Dahlheim glass, "A"
LINEMU Henke (LBL, 1985) < 10KeV / CITZMU > 10KeV
Elemental Weight Percents:
ELEM: Si Al Mg Ca O TOTAL
1 23.162 8.549 6.851 16.688 45.030 100.281 Armstrong/Love Scott (default)
2 23.300 8.553 6.800 16.705 45.030 100.389 Conventional Philibert/Duncumb-Reed
3 23.392 8.535 6.884 16.671 45.030 100.512 Heinrich/Duncumb-Reed
4 23.171 8.549 6.846 16.694 45.030 100.290 Love-Scott I
5 23.139 8.554 6.843 16.689 45.030 100.255 Love-Scott II
6 22.797 8.632 6.704 16.733 45.030 99.895 Packwood Phi(pz) (EPQ-91)
7 23.055 8.516 6.802 16.650 45.030 100.053 Bastin (original) Phi(pz)
8 23.262 8.515 6.868 16.707 45.030 100.381 Bastin PROZA Phi(pz) (EPQ-91)
9 23.186 8.540 6.846 16.707 45.030 100.308 Pouchou and Pichoir-Full (Original)
10 23.129 8.558 6.819 16.707 45.030 100.243 Pouchou and Pichoir-Simplified (XPP)
AVER: 23.159 8.550 6.826 16.695 45.030 100.261
SDEV: .159 .033 .051 .023 .000 .175
SERR: .050 .010 .016 .007 .000
MIN: 22.797 8.515 6.704 16.650 45.030 99.895
MAX: 23.392 8.632 6.884 16.733 45.030 100.512
PUBL: 23.240 8.510 6.670 16.550 45.030 100.00
It's great that we still have these glasses available for new measurements.
john
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It can probably be determined from the compositions, but someone(!) should make a list correlating the Oregon Dahlheim glass letter designations with the Cal Tech P standard numbers.
Since we actually have mounts and material available for these glasses, further investigations would be quite useful I think.
By the way, the glass measurements I did in the MDB file above are just a first attempt, but measurements at multiple keVs would be even more useful from a matrix correction comparison perspective, so if someone would like to borrow my Dalheim glass mount I would be pleased to share it. The only anomaly I saw in my initial efforts some 10 years ago was that glass "J" seemed to be a duplicate of glass "C", but this could a mistake by the student mounting the glasses. Specifically it appears that what was labeled as glass "C" is actually glass "J", but this can be double checked.
Paul has all these materials (as do I), so this can be double checked. But they do seem to be very accurate and homogeneous glasses. It would be nice to get some "round robin" k-ratio measurements of these glass at multiple keVs from multiple instruments... if anyone is interested!
john
PS If you are looking for the original history of old EPMA instruments discussion that was here, I moved those comments here to a new thread for History of EPMA:
http://probesoftware.com/smf/index.php?topic=924.0
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Hello everyone!
I have been analyzing some U-Pu-Zr alloys using PFE. I am using Heinrich MACs, with extrapolation to actinide M lines. When I run "all matrix corrections", the differences between corrections are surprising to me.
U ranges from 54.3-55.9 wt.%, Pu ranges from 15.9-17.5 wt%, and Zr ranges from 22.0-25.6 wt%. The correction that I think is closest to "truth" is the Heinrich/Duncomb Reed correction, which reports (note totals are not close to 100% because fission products are not included here):
U 55.0 wt%
Pu 16.4 wt%
Zr 22.0 wt%
In contrast, the full PAP correction, which I think is fairly widely used and accepted reports:
U 55.5 wt%
Pu 16.8 wt%
Zr 23.9 wt%
When I look at all the correction factors what sticks out to me is the absorbance correction for Zr. It is much higher in most of the matrix correction algorithms than in the Heinrich Duncumb Reed (HDR).
What I would like to do is try to understand why there is such a large difference (especially for Zr) between the PAP and HDR corrections. It seems to me that the most obvious way to do this is to find out what equations are used for each correction and compare them to one another to see how the k-ratios and MACs are treated differently.
So my questions are as follows:
1. Does this seem like a reasonable approach?
2. Does anyone know if the HDR correction was intended to be used with Heinrich MACs?
3. What literature specifically discusses the HDR correction? What I see from PFE is that HDR is composed of parameters from many different researchers. For example, its absorption correction is from Philibert [FRAME] and its mean ionization parameter is from Berger and Selzer. Do we know that these parameters developed by different researchers are internally consistent and are meant to be used together? I can't find literature that specifically discusses HDR in depth.
4. On what types of samples was HDR designed and tested?
Any insight will be greatly appreciated!
Cheers,
Karen
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Hi Karen,
I moved your topic to this existing topic (with the exact same name!)... so you might want to check the previous posts in this topic. I should also suggest that you check out the CalcZAF feature shown here:
(https://probesoftware.com/smf/gallery/1_19_07_23_3_26_37.png)
This requires you to export a composition from Probe for EPMA (which was analyzed as a standard, but you said you thought you knew what the composition should be...) using the PFE Output | Save CalcZAF Standard Format menu, and then run CalcZAF to apply all 10 matrix corrections and all 7 MAC tables as shown here:
(https://probesoftware.com/smf/gallery/1_19_07_23_3_26_55.png)
The output file (or at least a piece of) is shown here loaded into Excel, so you can plot histograms of the different matrix corrections and MAC combinations to see what the distributions are:
(https://probesoftware.com/smf/gallery/1_19_07_23_3_27_10.png)
Maybe this will be useful.
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Hi John,
I had done what you suggested before I posted here. That is what showed me that there is a significant absorbance correction difference between HDR and PAP for Zr. Why that is, is what I would like to understand.
Karen
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It's a good question. One would have to examine the details of the equations utilized, which can be found on Github. The ZAF.BAS routine contains the source code for all the corrections:
https://probesoftware.com/smf/index.php?topic=570.0
In general one can only say that the Heinrich-Duncumb-Reed method is an older ZAF type correction that is quite different from the more modern PAP phi-rho-Z method which combines the absorption and atomic number corrections. Realistically one should combine the absorption and atomic number corrections in HDR and compare those combined absorption and atomic number correction values in the PAP method. Of course just because a method is newer doesn't mean that it's better... it depends on the compositions involved.
That's because, the largest differences in these two methods are probably the standard materials utilized to "tune" these the equations at the time they were created. PAP used the POUCHOU.DAT and POUCHOU2.DAT k-ratio databases (provided with CalcZAF and found in the CalcZAFDATData folder), while the HDR method probably utilized a different k-ratio database (I'm not sure which, but it could have been the NISTBIN.DAT k-ratio database which is also found in the CalcZAFDATData folder).
You might want to contact Brian Joy at Queens University as he has looked into these equations in some detail.
My final comment is that with high atomic number materials like this, the backscatter correction can be quite large and because current backscatter corrections are improperly based on mass concentrations, there are significant errors associated with them in some compounds. This is the motivation behind our recent paper:
https://probesoftware.com/smf/index.php?topic=1111.msg11954#msg11954
And we are working on implementing a new backscatter correction in CalcZAF/PFE as I write this. You might want to look at the A/Z ratios of the elements in this material and see how different they are. The more difference in the elemental A/Z ratios in a compound, the larger the mass bias effects in the backscatter correction.
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Hi,
I am trying to compare some old data sets, done on our previous probe (Cameca SX-50) with the Geller software, with some new data.
I am not familiar with the Geller software and the processing computer is around but in storage. Does anyone know what the Geller software likely used as the MAC set and is the PAP different somehow or the same as the one in CalcZAF/PFE?
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Hi,
I am trying to compare some old data sets, done on our previous probe (Cameca SX-50) with the Geller software, with some new data.
I am not familiar with the Geller software and the processing computer is around but in storage. Does anyone know what the Geller software likely used as the MAC set and is the PAP different somehow or the same as the one in CalcZAF/PFE?
As far as I know, the Geller dQuant used one of the matrix corrections from Armstrong's CITZAF code. If they used the PAP code from Armstrong' CITZAF there are two things I can mention.
First, there were some typos in the CITZAF PAP code which Paul Carpenter and Brian Joy and I fixed in CalcZAF. This is documented in the code on the CalcZAF GitHub.
Second there was another bug in the fluorescence correction in CITZAF that Donovan fixed in CalcZAF very early on, but I think Geller fixed that bug around the same time as he reported it to them.