Questions about MAN background use

[AndrewLocock]

[If someone has a ASCII table with these Auger lines feel free to post it.  We would like to have at least the text labels, energies and nominal intensities for each emission line.

The Coghlan and Clausing 1973 reference is: Atomic Data and Nuclear Data Tables, volume 5, issue 4, pp. 317-469, and may be found at
https://doi.org/10.1016/S0092-640X(73)80005-1

More recent progress in simulation and calculation of electron spectra and Auger kinetic energies are given by:

Smekal, W., Werner, W.S. and Powell, C.J., 2005. Simulation of electron spectra for surface analysis (SESSA): a novel software tool for quantitative Auger‐electron spectroscopy and X‐ray photoelectron spectroscopy. Surface and Interface Analysis: An International Journal devoted to the development and application of techniques for the analysis of surfaces, interfaces and thin films, 37(11), pp.1059-1067.

Werner, W.S., Smekal, W. and Powell, C.J., 2011. NIST Database for the Simulation of Electron Spectra for Surface Analysis (SESSA). In Version 1.3, Standard Reference Program Database 100, US Department of Commerce. National Institute of Standards and Technology Gaithersburg, MD.

Dean, J.W., Chantler, C.T. and Ganly, B., 2022. Ab initio calculations of Auger electron kinetic energies: Breadth and depth. Radiation Physics and Chemistry, 200, p.110472.

Unfortunately, the online NIST X-ray Photoelectron Spectroscopy Database is not comprehensive:
https://srdata.nist.gov/xps/Default.aspx

[John Donovan]

I also calculated data for MAN BG curve. It is a bit different topic but could you explain how I can download the calculated MAN BG to PFE.

The mean atomic number (MAN) background correction curve is not a static fit. It is a dynamic fit based on the current selection of standards available and/or selected by the user and also corrected for standard intensity drift in real time and of course the current standard compositions. Also to a very small degree, the current dead time constants and equations.

In addition it is affected by the choice of the model for the calculation of average Z.  Traditionally we have utilized a mass fraction model, but we now know (publication coming soon), that mass has nothing to do with continuum production and so one should generally select the Z Fraction model which is based on the number of atoms and their atomic numbers which scales roughly as Z^2/3.  There is a topic here that explains this:

https://probesoftware.com/smf/index.php?topic=1221.msg10187#msg10187

To answer your question though, one can only import the standard intensities utilized in the MAN fit from another Probe for EPMA probe run. This can be done at any time whenever the Load File Setup button is selected from the Acquire! window New Sample/Setup button and the user clicks Yes to the question: Do you want to load the standard intensities?  after the sample setup has been loaded.

[John Donovan]

Here is the new Z fraction average Z calculation using a fixed exponent as described in our recent paper this summer:

https://academic.oup.com/mam/article-abstract/29/4/1436/7224307



Here the Z fraction exponent is fixed at 0.7 for all MAN elements.  However, starting with v. 13.4.4 of Probe for EPMA you can now change this exponent to a zero and the program will automatically calculate the optimized exponent based on the emission line energy (as described in the paper linked above).

Here we've entered a zero for the Z fraction exponent and clicked the Update Fits button. We can can now see the calculated "optimized" Z bar exponent is 0.67 which produces a better Rel % Deviation fit to the MAN standards:

[John Donovan]

Note that if you have these two options checked in the Analytical | Analysis Options menu dialog:



you will see the MAN fit details for the optimized Z fraction exponent, "ZEXP:" parameter:

St  310 Set   2 SM Fayalite, Results in Elemental Weight Percents
 
ELEM:       Si      Al      Ca       K      Ti      Cr      Fe      Mn
TYPE:     ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL
BGDS:      MAN     MAN     MAN     MAN     MAN     MAN     MAN     MAN
MAN1:  .165963 2.59049 -.08976 -.10492 -.36600 -1.2218 -.18728 .109394
MAN2:  .196322 -.22066 .068148 .119022 .255554 .312196 .102628 .039946
MAN3:  .000000 .012323 .000000 -.00014 .000000 -.00291 .000000 .001477
ABS%:   -27.70  -39.15   -3.56   -5.55   -1.30    -.28     .18     .00
ZEXP:      .64     .63     .69     .68     .70     .72     .73     .73
TIME:    40.00   40.00   40.00   20.00   20.00   40.00   25.00   25.00
BEAM:    19.97   19.97   19.97   19.97   19.97   19.97   19.97   19.97

Assuming the MAN Z Fraction exponent is set to zero...

[AndrewLocock]

Here is the new Z fraction average Z calculation using a fixed exponent as described in our recent paper this summer:

https://academic.oup.com/mam/article-abstract/29/4/1436/7224307



Here the Z fraction exponent is fixed at 0.7 for all MAN elements.  However, starting with v. 13.4.4 of Probe for EPMA you can now change this exponent to a zero and the program will automatically calculate the optimized exponent based on the emission line energy (as described in the paper linked above).

Here we've entered a zero for the Z fraction exponent and clicked the Update Fits button. We can can now see the calculated "optimized" Z bar exponent is 0.67 which produces a better Rel % Deviation fit to the MAN standards:

A related request - can you arrange for Probe-for-EPMA to export the graphic of the MAN assignment and fit for each X-ray line used?
At present, I use the Windows Snip tool and dump the graphic into Word (see attached).
In this way, I can the reference materials used (or most of them), the Rel% Deviation, the Curvature, the Slope and Intercept, as well as the Z-bar Exponent.

Further question - what are acceptable values or ranges in the MAN fit for: the Rel% Deviation, the Curvature, the Slope and Intercept?
At present, I like to have Rel% Deviation certainly less than 3, preferably less than 2.
I like to have the Intercept close to zero (not always possible, unclear as to why).
What do others find acceptable?

Thanks,
Andrew

[John Donovan]

A related request - can you arrange for Probe-for-EPMA to export the graphic of the MAN assignment and fit for each X-ray line used?
At present, I use the Windows Snip tool and dump the graphic into Word (see attached).
In this way, I can the reference materials used (or most of them), the Rel% Deviation, the Curvature, the Slope and Intercept, as well as the Z-bar Exponent.

If you click the Print Additional MAN Fit and Correction Parameters checkbox as described here:

https://probesoftware.com/smf/index.php?topic=4.msg12053#msg12053

much if not all of this info is output to the log window.

Further question - what are acceptable values or ranges in the MAN fit for: the Rel% Deviation, the Curvature, the Slope and Intercept?
At present, I like to have Rel% Deviation certainly less than 3, preferably less than 2.
I like to have the Intercept close to zero (not always possible, unclear as to why).
What do others find acceptable?

The MAN fits in your Word document in the post above look really good to me.  I guess it just depends on the sensitivity/accuracy you require.  The 2016 MAN paper goes into this in some detail:

https://epmalab.uoregon.edu/publ/A%20new%20EPMA%20method%20for%20fast%20trace%20element%20analysis%20in%20simple%20matrices.pdf

[John Donovan]

A related request - can you arrange for Probe-for-EPMA to export the graphic of the MAN assignment and fit for each X-ray line used?
At present, I use the Windows Snip tool and dump the graphic into Word (see attached).

Note that you can also use the <alt> <Print Screen> key combo to capture just the current window to the system clipboard.

We could also add a "Clipboard" button to the MAN dialog.

[John Donovan]

The latest version of Probe for EPMA v. 13.5.9 now includes a Clipboard button in the MAN window and also outputs the MAN coefficients and relative % deviations (and exponents if utilizing the Z Fraction MAN fit option) if using the Print MAN Fit and Correction Parameters to Log Window (and Use Detailed Output) option from the Analytical | Analysis Options dialog which can be see here for mass fraction MAN Z bar calculation:

St  358 Set   2 Diopside (Chesterman), Results in Elemental Weight Percents
 
ELEM:       Na      Si       K      Al      Mg      Fe      Ca      Mn       O       H
TYPE:     ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    SPEC    SPEC
BGDS:      MAN     MAN     LIN     MAN     MAN     MAN     MAN     LIN
MAN1:  8.21064 17.6972         15.1856 -23.560 3.60143 4.96464                       
MAN2:  .298724 .235361         1.31971 5.10899 .135131 2.51710                       
MAN3:  .039522 .000000         .016978 -.09491 .014340 .018263                       
REDV:     5.88   11.90             .77    3.37     .93    1.89                       
ABS%:   -45.67  -17.88          -27.57  -30.56    -.79   -2.99                           

And here for Z fraction MAN Z bar calculation (constant exponent) with the constant exponent:

St  358 Set   2 Diopside (Chesterman), Results in Elemental Weight Percents
 
ELEM:       Na      Si       K      Al      Mg      Fe      Ca      Mn       O       H
TYPE:     ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    SPEC    SPEC
BGDS:      MAN     MAN     LIN     MAN     MAN     MAN     MAN     LIN
MAN1:  4.05116 17.6299         15.3465 -30.781 1.65561 -2.6997                       
MAN2:  .850560 .251887         1.24988 6.25317 .366658 3.66492                       
MAN3:  .028771 .000000         .025809 -.12994 .010452 -.00973                       
REDV:     7.10   11.91            1.88    1.81     .22    4.33                       
ABS%:   -45.67  -17.88          -27.57  -30.56    -.79   -2.99                       
ZEXP:      .70     .70             .70     .70     .70     .70                           

And here for Z fraction MAN Z bar calculation (variable exponent):

St  358 Set   2 Diopside (Chesterman), Results in Elemental Weight Percents
 
ELEM:       Na      Si       K      Al      Mg      Fe      Ca      Mn       O       H
TYPE:     ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    ANAL    SPEC    SPEC
BGDS:      MAN     MAN     LIN     MAN     MAN     MAN     MAN     LIN
MAN1:  2.00334 17.6443         14.9056 -32.456 1.84603 -3.2513                       
MAN2:  1.13292 .253212         1.30209 6.52835 .344140 3.74527                       
MAN3:  .021317 .000000         .025652 -.13876 .010783 -.01194                       
REDV:     7.63   11.92            2.34    1.50     .16    4.45                       
ABS%:   -45.67  -17.88          -27.57  -30.56    -.79   -2.99                       
ZEXP:      .62     .64             .63     .63     .73     .69                         

[John Donovan]

We also modified the Report output table format to include MAN statistics as requested by Andrew Locock: