Nonstationary oscillation of gyrotron backward wave oscillators with cylindrical interaction structure

Journal Article · Sun Dec 15 04:00:00 EST 2013 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4846876· OSTI ID:22218363

Chen, Shih-Hung ^[1]; Chen, Liu ^[2]

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1. Department of Physics, National Central University, Jhongli 32001, Taiwan (China)
2. Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)

The nonstationary oscillation of the gyrotron backward wave oscillator (gyro-BWO) with cylindrical interaction structure was studied utilizing both steady-state analyses and time-dependent simulations. Comparisons of the numerical results reveal that the gyro-BWO becomes nonstationary when the trailing field structure completely forms due to the dephasing energetic electrons. The backward propagation of radiated waves with a lower resonant frequency from the trailing field structure interferes with the main internal feedback loop, thereby inducing the nonstationary oscillation of the gyro-BWO. The nonstationary gyro-BWO exhibits the same spectral pattern of modulated oscillations with a constant frequency separation between the central frequency and sidebands throughout the whole system. The frequency separation is found to be scaled with the square root of the maximum field amplitude, thus further demonstrating that the nonstationary oscillation of the gyro-BWO is associated with the beam-wave resonance detuning.

• OSTI ID: 22218363
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 12 Vol. 20; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
CYLINDRICAL CONFIGURATION
ELECTROMAGNETIC RADIATION
FEEDBACK
MICROWAVE AMPLIFIERS
OSCILLATIONS
OSCILLATORS
RESONANCE
TAIL ELECTRONS
TIME DEPENDENCE