Title :
Gyro-BWO experiments using a helical interaction waveguide
Author :
He, Wenlong ; Ronald, Kevin ; Young, Alan R. ; Cross, Adrian W. ; Phelps, Alan D R ; Whyte, Colin G. ; Rafferty, Euan G. ; Thomson, Jamie ; Robertson, Craig W. ; Speirs, David C. ; Samsonov, Sergey V. ; Bratman, Vladimir L. ; Denisov, Gregory G.
Author_Institution :
Dept. of Phys., Univ. of Strathclyde, Glasgow, UK
fDate :
5/1/2005 12:00:00 AM
Abstract :
A helically corrugated waveguide was used for a gyrotron backward-wave oscillator (gyro-BWO) experiment. A thermionic cathode was used to produce an electron beam of 90-215 keV in energy, 2-3 A in current, and pitch alpha of up to 1.6. The oscillator achieved high-efficiency frequency-tunable operation. At a fixed beam voltage of 185 kV and a current of 2 A, the output frequency was tuned by adjusting the magnetic field in the interaction cavity. A maximum power of 62 kW and a 3-dB frequency-tuning band of 8.0-9.5 GHz (17% relative tuning range) with a maximum electronic efficiency of 16.5% were measured. In addition, the interaction frequency could be tuned by varying the electron beam energy. At a fixed cavity magnetic field of 0.195 T, the output frequency and power from the gyro-BWO were measured as a function of tuning electron beam energy while the beam current was maintained at 2.5 A. A 3-dB relative frequency tuning range of 8% was measured when the electron beam voltage was changed from 215 to 110 kV.
Keywords :
backward wave oscillators; gyrotrons; helical waveguides; thermionic cathodes; 0.195 T; 16.5 percent; 185 KV; 2 to 3 A; 62 KW; 8 to 9.5 GHz; 90 to 215 KeV; cavity magnetic field; cyclotron-resonance maser; electron beam energy; frequency tuning; frequency-tunable operation; gyro-BWO experiments; gyrotron backward-wave oscillator; helical interaction waveguide; helically corrugated waveguide; high-power microwave devices; thermionic cathode; Current measurement; Electron beams; Energy measurement; Frequency measurement; Gyrotrons; Magnetic field measurement; Oscillators; Power measurement; Tuning; Voltage; Cyclotron-resonance maser; gyrotron backward-wave oscillator (gyro-BWO); high-power microwave devices;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2005.845858