Operating modes of relativistic rising-sun and A6 magnetrons
Abstract
The operating characteristics of a relativistic 16-vane rising-sun magnetron were investigated with particular emphasis on determining the operating regimes of different modes. The magnetron performance was studied as a function of voltage, magnetic field, cathode geometry, axial boundary conditions, and ouput coupling. Operation was observed in the 3 pi/8 mode at 3.3 GHz, in the pi/2 or 3 pi/8 mode at 3.5 GHz, and in the pi or 7 pi/8 mode at 4.6 GHz. A maximum power of 80 MW was emitted in the 3 pi/8 mode with an efficiency of 4.5 percent. Typical pulse lengths were 40-50 ns. Cold tests were performed to measure the resonant frequencies and azimuthal electric fields in the interaction space which agreed within 1-4 percent of theoretical calculations. The operating modes were inferred from close agreement between hot-test frequencies and cold-test results and because high-power RF emission occurred at, or just above, the Buneman-Hartree threshold calculated for these modes. The characteristics of a six-vane A6-magnetron operating in the pi and 2 pi modes were also studied. A unique transmitting-receiving system, which was used as a microwave diagnostic, is described.
- Publication:
-
IEEE Transactions on Plasma Science
- Pub Date:
- April 1988
- DOI:
- 10.1109/27.3820
- Bibcode:
- 1988ITPS...16..237T
- Keywords:
-
- Magnetrons;
- Microwave Coupling;
- Power Efficiency;
- Resonant Frequencies;
- Volt-Ampere Characteristics;
- Network Analysis;
- Phase Shift;
- Electronics and Electrical Engineering