Jagadishwar submitted the following abstract for IVEC-2003 on 1/24/03.



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A Novel High Power 140 GHz Quasioptical Gyro-TWT
J. R. Sirigiri, E. Choi, C. Joye, M. A. Shapiro and  R. J. Temkin 
MIT - Plasma Science and Fusion Center, Cambridge, MA 02139

We present the experimental results from a novel high power 140 GHz gyro-TWT
with a quasioptical interaction structure. The gyro-TWT amplifier is
designed to generate 100 kW at 140 GHz with 38 dB gain and 3% saturated
bandwidth. The interaction structure is a highly overmoded quasioptical open
waveguide namely, a confocal waveguide which has the capability of up to 100
kW CW operation in the W-band (94 GHz) when built to industrial standards. A
high average power capable quasioptical sever based on diffraction losses is
demonstrated in the experiment. The latest experiments in microsecond pulsed
operation have yielded  peak power of 30 kW for a 68 kV, 6A beam and 10 kW
of power over a 2 GHz bandwidth in unsaturated operation.


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