Papers by Keyword: Secondary Electron Emission

Abstract: Secondary electron emission (SEE) processes play an essential role in spacecraft surface charging. It is difficult to study SEE of insulator whose surface cumulates charges by incident electron bombardment because of poor conductivity. This paper investigated the theoretical process of generation, transfer and escape of secondary electrons, and finally the paper presented a mathematical model to calculate the secondary electron emission. We also have improved measurement system to measure total SEE coefficient from dielectric with 1-5 keV electron irradiation which is perfectly fit to mathematical model, and the SEE coefficient with different surface charging is investigated. The results indicate the SEE coefficient decreases with positive charging and increase with negative charging of dielectric surface.

Abstract: High purity MgO is a common ceramic material used as a protecting layer in an alternating current plasma display panel (AC-PDP). In this work, pure MgO was added by CaO for a better protecting layer. The effect of CaO addition was discussed according to the changes in the microstructure, mechanical strength and the ability of the sample to withstand surface breakdown (flashover) with various CaO addition in the powder mixture. In addition, it was found that 2.5 wt% CaO-addition shows a better electrical discharge. Since secondary electron emission coefficient contributes in the electrical discharge, it could be predicted that the 2.5 wt% CaO added MgO has a higher secondary electron emission constant and becomes a promising candidate for a protecting layer in AC-PDP.