An improved tapered MILO

An improved magnetically insulated line oscillator with several slow wave cavities and double-cavity extraction structure is presented and analyzed. By computing the dispersion curve of the SWS, and using the PIC code, optimized structures with the beam-wave conversion efficiency of 15% in S band and in L band have been designed. Some reasons which infect the operation stability of these devices are also discussed. In the following experiments, microwave with an averaged power of 3GW at 2.61GHz and an averaged power of 3GW at 1.56GHz is generated separately by using these structures which are fed by the water-filled Blumlein pulse forming line accelerator named Spark03. The measured efficiency is about 12%. Otherwise, a Ku-band tapered MILO which has been designed based on the same principle is also presented.