L-band slot antenna design for gigawatt-level single-pulse microwave sources

Summary form only given, as follows. One significant problem with the evacuated Vlasov antenna used in the present-day gigawatt-level, 1.2-GHz magnetically insulated line oscillator (MILO) experiments is rf breakdown in the antenna aperture. In order to reduce the field stress inherent in a single-aperture antenna at gigawatt power levels, an 81-slot non-resonant (traveling wave) antenna has been constructed. The intent of this design is to reduce the rf electric field in any one aperture below the vacuum breakdown threshold, and yet maintain a desirable far-field pattern having a localized and intense power density profile. We report on cold testing results from the slot antenna as well as on theoretical analysis of the antenna using a transmission line model aided by computer simulations. In addition, experimental data obtained using this antenna on MILO are presented.