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We present a general technique to assess and remove unwanted contributions from closely spaced features in spectra acquired using Auger-photoelectron coincidence spectroscopy. We use the Ag 3d[sub 5/2] and 3d[sub 3/2] core levels and their associated core valence-valence Auger decays, the Ag M[sub 5]VV and M[sub 4]VV Auger lines, to demonstrate this technique. Ag M[sub 5]VV and M[sub 4]VV Auger spectra were obtained in coincidence with 3d[sub 5/2] and 3d[sub 3/2] core photoelectrons, respectively. We have also measured the 3d[sub 5/2] and 3d[sub 3/2] core level spectra in coincidence with M[sub 5]VV and M[sub 4]VV Auger electrons. In the coincidence spectra, the contribution from the spin-orbit partner is considerably reduced but, in general, not eliminated. However, by measuring all four coincidence spectra, enough information is obtained to unambiguously assess and remove the unwanted contributions and thus determine the intrinsic line shape of the M[sub 5]VV and M[sub 4]VV Auger lines. As a cross-check of this subtraction technique, we find that the intrinsic M[sub 5]VV and M[sub 4]VV line shapes give an excellent account of the conventional, noncoincidence Ag M[sub 4,5]VV spectrum with the expected 6:4 ratio. The correction technique described here can be applied to a large number of systems where the close separation of core lines produces additional spectral features in the coincidence measurements of their associated Auger spectra. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Presents an abstract of a paper presenting a simple scheme for precision alignment of grating monochromators. Alignment resolution of the roll axis; Application of the alignment method to the monochromators at X13A and U13U beamlines at the National Synchrotron Light Source in Upton, New York.