Predicting total secondary electron emission from porous surfaces using a 3D pore geometry

Abstract

Multipactor is a critical problem in satellites and vacuum electron devices (VEDs). Described as an “avalanche” of electrons in radio frequency (RF) and microwave devices under vacuum, multipactor is caused by repeated secondary electron emission (SEE) stimulated by a time-varying electric field. Its effects range in severity from a temporary disruption in device operation to arcing, melting, cracking, or destruction of the device. A new and promising field of multipactor suppression research is engineering the internal surface topography of a VED to limit the secondary electron yield (SEY) to unity or less. Such low values of SEY render impossible the growth in electron population that is necessary to initiate the electron avalanche in a multipactor. We have developed a new model to predict the SEY of a porous surface which is useful to determine optimal topographies to control SEY. In order to assess how porous surfaces will be effected by extreme temperatures encountered in space we performed thermomechanical simulations of single gold pores. Finally, we discuss the design and fabrication of various microporous and nanoporous surfaces that will be used to validate the model in a future experimental SEY study.