Positive and negative ion desorption from PVC as studied by electron stimulated desorption

With the aim of performing time-of-flight studies of electron stimulated ion desorption (ESID) from polymers bombarded with a variable energy electron beam source, an experimental set-up including a homemade time-of-flight mass spectrometer has been developed for positive and negative ion analysis. This system uses as a trigger for the experiments either the pulsed electron beam or the pulsed (positive/negative) extraction high voltage applied to the sample. Results for both positive and negative ion desorption from poly(vinyl chloride) (PVC) obtained in ESID measurements with these two different modes of operation will be presented and discussed.