Thank you Gents for your replies.
I stand "corrected" on the PeakSight fluff, but would like to read the Jercinovic and Allaz paper on why the CAMECA corrections were, erm, incorrect....
Re my question 4:
John, I've read both papers as requested and can find NO mention of EXACTLY how to implement cascade interference corrections in the PfE software (hence my last question #4 in my original post). Perhaps question 4 was not worded specifically enough.
The first paper ("An Improved Interference...") goes through the matrix correction and overall calculation logic, but the first four examples cited in that paper involve ONE interfering element on ONE interfered element (P-Zr, Ba-Ti, Fe-F, Fe-Co). Only the last, fifth, example mentions the cascade Ti on V then V on Cr inteferences, but the paper does not inform me how to implement the cascade interference correction procedure in PfE. Reading Julien's "Quick Instructions on Mnz and Xno Analyses" pdf does that to some extent....
Section 12 of Julien's Quick Instructions shows his standard assignment for UMb including Th and K interferences. In MY case, assuming I stick with using the PbMb line, I will also have U interferents on PbMb on two channels (plus Th on UMb on both channels - from Julien's earlier reply).
My followup question: does PfE look through the list of elements and respective interferents then decide which to correct in the appropriate, correct cascade sequence, i.e. do I just put in the interferences in the std assignments window and let PfE do the rest, OR is there another box/window somewhere that I have to specify the cascade correction order? My experiences with the SAMx software were that the cascade interference correction sequence could be explicitly specified by the user, e.g. Th on U then U on Pb (although it could not do aggregate intensities at that time, circa 1998-2003).
Re my earlier question 3:
"do I need to measure Th and U as well as Pb on both channels to have the interference corrections done "correctly", or is having the appropriate interference corrections assigned to the respective channels sufficient?".... has not been answered.
Yes I know I need to pre-acquire the appropriate interference standards on both channels and have them assigned on both channels but my question should possibly have been "do I need to acquire Th and U on both channels during an 'unknown' acquisition together with Pb on both to have the appropriate interference corrections applied?", OR is John implying by refering me to read the "Improved Interference.." paper that once the concentrations of Th and U are estimated in the matrix (possibly acquired using a third or fourth spectrometer, i.e. non-Pb channel acquisition) that it is not necessary to acquire Th and U intensities on the Pb-acquisition channels to have the appropriate cascade interference corrections done?
I am simply trying to work out exactly how to implement all the stuff in PfE to get it to do what I require! I have tripped over and been tripped over enough times in the past 8 months with making assumptions about the PfE logic to not want to waste further time and effort trying to implement a method an inappropriate way!
(to paraphrase John, "The only silly question is one that isn't asked"....)
My chemical dating method implemented via PeakSight on the Edinburgh SX100 multiple beam conditions, e.g. La, Ce, P, Al and Nd at 20kV, 20nA then U, Th, Pb(*2), and the other (high) REEs plus Si and Y at 20kV, 100nA. In total a circa. 8 minute acquisition.
The caveat with PfE and multiple conditions is that the first column conditions used are by default the conditions specified for the first element on channel 1 (as you'd know). So you have to fiddle with the element sequence to get PfE to acquire using the appropriate conditions sequence. In my first attempt using PfE and multiple conditions I got caught trying to measure C in steel: C at 7kV, the other elements (Fe, Mn, Cr, Mo etc at 15kV). Unfortunately my LDE2 xtl is on channel 3, so PfE runs the 15kV elements first then does C. So much for avoiding C contamination. I had the anticontamination trap working that day! For my next iteration I'll have to try C at the top of the LDE1, which is on channel 1, unless JD will change the PfE code.
John, could you change the code to allow the user to specify the beam condition order irrespective of the element/channel combination, rather than the current enforced "default" as indicated above? If the user can specify the element acquisition order, and we already link the elements to specific conditions in a multiple condition setup, why can't we go a step further and be able to specify the multiple condition order (irrespective of the first element on channel 1...)?
PS: I like Julien's "Quick Instructions for Monazite and Xenotime Analyses using PfE".... all 50 pages of it! Very thorough, but very necessary....
Possibly a question more appropriate in the monazite chemical dating topic, but.... Julien are you measuring UMb on a highP detector to avoid the detector Ar K abs edge (my numerous CAMECA scans over that edge show that the edge is very obvious on the low P detectors but is alomst non-existent on the high P detectors on the CAMECA EPMAs), or are you positioning your multi-point bgds for UMb above that edge, and also avoiding sample major element abs edges....??
Thanks again and cheers,
David