A SYSTEM FOR THE INTENSITY CALIBRATION OF ELECTRON SPECTROMETERS

A system for the calibration of the intensity/energy response function for electron spectrometers used in Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) is described. The basic phy sical principles of a complete system are detailed to show how the dat a are derived and how the calibrations may be made traceable to the SI system. The calibration method gives an accurate energy dependence of the intensity/energy response function which is the functional depend ence presently needed for analytical work. For AES this gives a reprod ucibility demonstrated below 2% and for XPS at 4%. For AES this is als o made traceable in an absolute sense, where the response function is given in sr eV units, to an accuracy of 6%. For XPS the units of the r esponse function are also sr eV for focused X-ray monochromators but f or diffuse unmonochromated X-ray sources m(2) sr eV units are more app ropriate. Accurate traceability for XPS exists for all terms except th e X-ray source production efficiency. The full traceability is importa nt for those studying absolute cross sections but is usually unimporta nt where quantification procedures involve any normalisation procedure s.