A GENERAL AND SIMPLE APPROACH FOR THE DETERMINATION OF ENERGY ANALYZER TRANSMISSION FUNCTIONS

The transmission function of energy analyser LHS-11 from Leybold-Heraeus has been obtained from the dependence of the signal intensity on the instrument pass energy (E(p)) at a given kinetic energy of the incident electrons (E(k)). For the energy analyser, the transmission function has been expressed by the equation [GRAPHICS] A slight dependence of the exponent n on E(k) is observed, and it has been fitted by the equation [GRAPHICS] This is a very general characterization of the transmission that gives its analytical description in the whole XPS range for a given set of operational parameters, such as slit dimensions, sample size and sample position. From the transmission function obtained and using reported values of the photoionization cross-sections, two sets of XPS sensitivity factor for several elements have been calculated. With these factors, the surface concentrations of a multi-element sample have been determined with good agreement between the values after Mg and Al K-alpha excitation. These results suggest that corrections due to variations in the transmission function with E(k) can improve the accuracy of the calculated sensitivity factors.