Concern with all L-type being extremely high count rate when analyzing silicates at high current. Any foreseeable issues with switching to lower intensity 2nd & 3rd order lines as suggested to us a way to justify all L-type?
Exactly! Large crystals are not problem-free and have the drawbacks.
We here in Warsaw University have 2 microprobes SX100 and SXFiveFE.
SX100:
Sp1: LiF, PET, TAP, PC0 (low pressure)
Sp2: PET, LiF (high pressure)
Sp3: TAP, PC2 (low pressure)
Sp4: LLiF, LPET (high pressure; added as an upgrade, made analysis more pleasant on that machine)
SxFiveFE:
Sp1: LTAP, LPC0 (extended spectrometer, low pressure)
Sp2: LLiF, LPET (high pressure)
Sp3: LLiF, LPET (high pressure)
Sp4: TAP, PC3, PC1, PC2 (low pressure)
Sp5: LLiF, LPET (high pressure)
With SXFiveFE there is one huge drawback: switching between analytical conditions back and forth is troublesome. And thus doing high current analysis and having no small PET hurts, as LPET with major element analysis suffers a lot from pile-up type of "dead-time" (I would call it rather blind time). We are doing a lot of complicated geological and geo-experimental minerals (sparingly some material science analysis) often containing 30+ elements (once I had hit the limit of Cameca Peaksight with 40 elements, took me two days to find out why could not do analysis with 41 elements). LTAP is not practical at all for such materials as background measurement is simply impossible to do due to wider peaks compared to TAP (even normal TAP suffers from that, and on our machine TAP (Sp4) is blanked from sides to make peaks more narrow). LPC0 is nice for N,O,F, but I think PC0 would do not so much worse. I think I would be more happy with getting rid of double-turret with LTAP and LPC0 and get quadruple turret (which can't mount large crystals) with TAP,
PET and PC0 (and probably move some other PC* from spectrometer 4).
As for SX100 - there is no big issue with the spectrometer configuration as the analytical conditions can be switched without drawbacks back and forth, and so there is no problem with running into pileup problem, simply by keeping the current respectively low.
BTW, pileup problem could be reduced with better pre-amplifiers and counting electronics.