New and simple mass calibration procedure for time-of-flight studies of electron stimulated desorption of ions from solid samples

A technique that provides a simple mass scale calibration for linear time-o f-flight (TOF) measurements is presented. This procedure has been used in t he calibration of the mass scale in experiments of electron stimulated deso rption of ions from solid surfaces. It is based on the admission of one or more calibration rare gases inside the ultrahigh vacuum chamber while a TOF spectrum of desorbing ions from the surface is simultaneously recorded. Pe aks related to desorbing ions as well as to the atomic gases can consequent ly be observed in the same mass spectrum, thus allowing an exact mass scale calibration. The present calibration procedure is especially suitable in t he low mass range (< 200 amu) and can be easily adapted for photon stimulat ed desorption experiments. (C) 2001 American Institute of Physics.