Relativistic magnetron experiments with a 6-vane, Titan tube have generated over 300 MW total microwave output power near 1 GHz. These experiments were driven by a long-pulse, e-beam accelerator. Parameters of the device were voltage = −0.3 to −0.4 MV, current = 1–10 kA, and pulselength = 0.5 microsecond.; This body of work investigated pulse-shortening in the relativistic magnetron. Microwave generation with a conventional plastic insulator was compared to that with a new ceramic insulator. The ceramic insulator improved the vacuum by an order of magnitude (1 × 10−7 Torr) and increased voltage stability of the accelerator. The effect of RF breakdown in the waveguide on the intensity and duration of high power microwaves were also investigated. These experiments found that when SF6 gas was introduced into the waveguide, the measured efficiency, power, and pulselength of microwaves increased.; Two different microwave extraction mechanisms were used. In the first system, two waveguides were connected to the magnetron π-radians from each other. The second system used three waveguides to connect to the magnetron's extraction ports at 2π/3 radians from each other. Microwaves were extracted into and measured from the waveguide. Pulselengths were found to be in the range of 10–200 ns.; The theoretical investigation calculates the maximum injected current for a time-independent cycloidal flow in a relativistic, magnetically insulated diode. The analytical theory of Lovelace-Ott was extended by relaxing the space charge limited (SCL) assumption. This theory reduced to Christenson's results in the deeply non-relativistic regime, and to Lovelace-Ott under SCL. This theory has been successfully tested against relativistic PIC code simulations.
展开▼
