When you add an element and it loads the theoretical peak position say for Si of 77.674 - where does it get this from, is it a table or an equation? Is it possible to change it to the actual peak positions?
Hi Ben,
I must not be following you exactly because I know that you know, that you can enter any peak position simply by typing it in... Yes, if you change an element/x-ray or spectrometer crystal, the program reloads the default on-peak to the value calculated from the XLINE.DAT table for this crystal.
This emission line table is visible from the CalcZAF app and the values can be edited in CalcZAF if you want to change the default emission line values. Note that because the CalcZAF/PFE installer tags this file (and the XEDGE.DAT and XFLUR.DAT files) as NeverOverwrite="yes" and Permanent="yes", they will never get overwritten or removed by the installer.
Now of course since even the theoretical peak positions will vary from spectrometer to spectrometer due to the spectrometer mechanical calibration, I almost *never* utilize the default peak positions and instead simply load previously peaked emission lines from the SETUP.MDB element setup database by using the Load Element Setup button in the New Sample Setup button or even easier, by loading an entire sample setup using the Load File Setup from a previous run where all the elements are peaked and the backgrounds already checked. See here for more information:
http://probesoftware.com/smf/index.php?topic=262.msg1242#msg1242I notice in the manual there is a peak calibration centre in startwin, but I loaded startwin and this option was greyed out - is it only possible on certain instruments?
Yes, the Startwin app has a feature to perform spectrometer calibrations over the range of each spectrometer (and crystal combination) using multiple elements on multiple standards. The description is in the PFE User Reference and I quote it here:
The Calibrate Peak Center option allows the user to specify a number of elements and corresponding standards for the program to perform multiple peak calibrations. After the peak centering has been performed the program will save the theoretical spectrometer positions along with the actual measured peak positions and a least squares fit to the data for the purpose of calculating a variable offset function which in turn is used to calculate the actual peak position of any element on that spectrometer/crystal combination.
There is a lot of details on this feature starting at page 105 or so. See attached below for some calibration results from my SX51 at UC Berkeley (remember, you need to be logged in to see attachments).
Basically the Peak Calibration feature in StartWin is a method to calibrate one's spectrometers *without* a mechanical recalibration. Since JEOL spectrometers require more frequent mechanical recalibration than Cameca spectrometers, I'm not sure it's worth the trouble for JEOL instruments. But some may disagree.
The feature should be enabled and allows one to specify up to 5 element/x-ray combinations per spectrometer/crystal combination for spectrometer calibration. If these calibrations are saved to the PFE peak calibration files (e.g., PROBEWIN-KA.CAL, PROBEWIN-KB.CAL, etc.), then they can be utilized when entering in a new element in the Elements/Cations dialog.
I haven't used this feature in ages, but Paul Carpenter was a big fan of this, at least at one time. We really should have someone write up a nice tutorial on it! Interested?
OK, I checked and I see that you have to have the UseMultiplePeakCalibrationOffset flag in the Probewin.ini file [software] section set to a non-zero value to enable the Peak Calibration button.
john