Analytical model of secondary electron yield from metal surface with regular structures

Abstract

An analytical model of secondary electron (SE) emission (SEE) from metal surface with regular structure is presented. In this model, the quantitative relationship between the SE emission yield (SEY) and surface topography is examined. Using the idea of multi-generation for SE emission, the first-generation of SEs is considered as being dominant in total SEs. The shielding effect of the surface structures on the SE is found to be the main factor influencing final SEY. On the basis of the cosine distribution of secondary electrons emission direction, the quantitative relationship between the SEY and surface topography parameters is revealed. Then taking the rectangular and triangular grooves for example, the analytical formulas of first-generation SEY are derived for both normal and oblique incidence. The analytical results are then verified with the Monte Carlo simulation results and experimental data. The results show that a rectangular groove with a bigger depth-to-width ratio can suppress the SEE more efficiently. For a triangular groove, owing to having both enhancing and suppressing effects on SEE, a small groove angle is required for effective SEE suppression. The present analytical model gives an insight into the relationship between the SEY and the surface topography parameters and is helpful for the structure design to modify SEY.