Development of High Efficient Technological Gyrotron with Depressed Collector

High power microwave radiation is applied for an ever increasing range of programs aimed to create materials with new qualities. The gyrotron complexes for microwave material processing created at IAP RAS jointly with GYCOM Ltd. do not have any analogues with similar functional capabilities but they are less effective than decimeter wavelength systems. The complexes use gyrotrons at the second cyclotron harmonic with the efficiency output of 30-40% as a source of microwave radiation. The expansion of gyrodevice based systems to novel technology and industrial applications requires further efficiency increase. The electron beam energy recovery is one of the most effective methods to achieve this. The presented results have been used for development of high efficiency harmonic gyrotron with depressed collector.