Ka-band Inverted Gyrotron with 80% Efficiency of Microwave-to-DC Power Conversion

The paper presents the results of the first experiments on the investigation of an inverted gyrotron or a gyrotron rectifier, a device which, unlike a conventional gyrotron, converts incident microwave power into direct current (DC) power. In the experiment, by means of cyclotron-resonance interaction with a thin solid initially rectilinear 8.4 keV/0.54 A electron beam, microwave radiation at a frequency of about 34 GHz with a power of 13 kW is converted by it into a power of 15 kW of a 70-μs pulse current that flows through a 51.4 kΩ resistor connecting the device collector to ground. The achieved efficiency of microwave-to-DC power conversion, taking into account the power to drive the electron beam, is 80%.