He, W. and Ronald, K. and Young, A.R. and Cross, A.W. and Phelps, A.D.R. and Whyte, C.G. and Rafferty, E.G. and Thomson, J. and Robertson, C.W. and Speirs, David and Samsonov, S.V. and Bratman, V.L. and Denisov, G.G. (2005) Gyro-BWO experiments using a helical interaction waveguide. IEEE Transactions on Electron Devices, 52 (5). pp. 839-844. ISSN 0018-9383Full text not available in this repository. (Request a copy from the Strathclyde author)
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, plasma, cyclotron-resonance maser, high-power microwave devices, Plasma physics. Ionized gases, Electronic, Optical and Magnetic Materials, Electrical and Electronic Engineering|
|Subjects:||Science > Physics > Plasma physics. Ionized gases|
|Department:||Faculty of Science > Physics|
|Depositing user:||Mr Derek Boyle|
|Date Deposited:||27 Mar 2007|
|Last modified:||24 Mar 2017 03:31|