Depressed collectors for gyrotrons

Because of the inherent advantages of gyrotrons, such a source is expected to be able to produce significantly higher power at high frequencies than that possible with a linear beam tube. A 10 GHz, 30 MW gyroklystron is being developed at the University of Maryland to demonstrate this potential. However, it is recognized that the gyroklystron´s efficiency is inferior to that of its linear beam counterpart because gyrotrons extract energy primarily from beam rotational motion only. Thus, for high average power systems, a method for enhancing the efficiency is important. Detailed calculations indicate that a depressed collector for the University of Maryland gyroklystron could have a high (≈76%) collection efficiency, yielding a doubling in the overall efficiency of the gyroklystron to 64%