Millimeter wave, 25 kW CW gyrotrons using permanent-magnets

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:428056

McDermott, D B; Luhmann, Jr, N C ^[1]

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1. Univ. of California, Davis, CA (United States). Dept. of Applied Science

Two compact 25 kW cw, low magnetic field gyrotrons have been designed for use in Ka-Band and W-Band systems. Both 50 kV devices have been designed to minimize their size and weight by using a 4.5 kG Samarium cobalt permanent magnet. Their designs are presented. The 35 GHz gyrotron uses a 3 A MIG and operates at the third harmonic in the TE{sub 411} mode of a smooth-bore cylindrical cavity. For an output power of 25 kW, the predicted conversion efficiency is 25%, yielding an output efficiency of 17%. An ideal 33 kV single-stage depressed collector following a magnetic downtaper could increase the device efficiency to 50%. The 94 GHz gyrotron utilizes a Cusp gun and operates at the eight-harmonic in a sixteen-vane slotted cavity. The efficiency of the 95 GHz gyrotron is predicted to be 10%, which could also be boosted to {approximately} 50% with a depressed collector. Either device can be reconfigured as a tunable gyro-BWO. Mode competition will be controlled in both gyrotrons by slicing the cavities to interrupt the azimuthal wall currents of unwanted modes as utilized recently in the successful second-harmonic TE{sub 21} gyro-TWT amplifier experiment.

• OSTI ID: 428056
• Report Number(s): CONF-960634--
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
CAVITY RESONATORS
DESIGN
ELECTRON GUNS
MAGNETIC MATERIALS
MICROWAVE AMPLIFIERS
MODE CONTROL
OSCILLATION MODES
PERFORMANCE