This Small Business Innovation Research Phase I project will develop high performance, vacuum compatible, lightweight materials with high surface flashover resistance for pulse power applications.In Phase I we will fabricate test samples of the proposed materials and measure their complex permittivities and vacuum flashover resistance (maximum supported field gradient); and determine their vacuum outgassing behaviors.Using the materials properties obtained we will design an HV component (HV standoff, window, or radome) for an HPEM source.ceramic,Dielectric,insulator,Surface Flashover,polymers,RADOMES,vacuum,window