Electron emission yield and charging process of alkali-silicate glass submitted to an electron beam under the varying temperature condition

Abstract

The electron emission due to electron impact of alkali-silicate glasses is measured with a technique based on the use of a Kelvin probe (KP method) and a pulsed electron beam. The KP method, allows a clear discrimination between the external and internal effects of charging process. The effect of the incident charge fluence, incident charge fluency and the temperature on the yield curve is investigated. It was found that, at room temperature as well as at 80 °C, electron emission varies with charge fluence. The effects of the temperature on charging mechanisms and charge transport characteristics of alkali-silicate glasses where also studied using the measurement of displacement and leakage currents under continuous electron irradiation in scanning electron microscope (SEM). The results clearly establish a correlation between charge carriers mobility and secondary electron emission yield. The enhancement of charge carrier mobility with increasing the temperature prevents the formation of a positive space charge (i.e. creation of positive ions and/or holes) that internally reduces the secondary electron (SE) emission. The higher is the temperature and the higher is the electron emission yield (EEY).