Demonstration of a high-power long-pulse 140-GHz gyrotron oscillator

CPI Microwave Power Products Div., Palo Alto, CA, USA
IEEE Transactions on Plasma Science (Impact Factor: 0.95). 07/2004; DOI: 10.1109/TPS.2004.828815
Source: IEEE Xplore

ABSTRACT A high-power long-pulse 140-GHz gyrotron oscillator has been designed, constructed, and tested. Key features of the gyrotron include an internal converter to transform the TE28,7,1 operating mode to a Gaussian output beam, a single-stage-depressed collector, and a chemical-vapor-deposition diamond output window. Peak output powers up to 930 kW at 34% efficiency have been demonstrated at 5-ms pulse lengths. Due to power supply limitations, long-pulse operation was not possible for beam currents above 25 A. At 25-A beam current and 500-kW output power, pulse lengths up to 700 s in duration were achieved. The gyrotron has been shipped to the Wendelstein 7-X facility in Greifswald, Germany, where long-pulse demonstrations up to 180s will be carried out at the 930-kW power level.

  • [Show abstract] [Hide abstract]
    ABSTRACT: A theoretical and experimental study on a 94 GHz low-voltage, low-current gyrotron is presented in this paper. In order to obtain stable radiation and make great use of the equipment in the lab, the TE6,2 mode is selected as the operating mode of the desired gyrotron. The efficiency of the electron beam interaction with RF fields under different conditions has been calculated by a code, which is based on the self-consistent nonlinear theory for gyrotrons. The gyrotron is equipped with a single-stage depressed collector and a quasi-optical mode converter. Then, a gyrotron with optimized parameters has been designed, constructed, and tested. An output power of 23 kW is obtained at an accelerating beam voltage of 31.5 kV, a beam current of 1.8 A, and a collector depression voltage of 7.4 kV, corresponding to an overall efficiency of 53%.
    IEEE Transactions on Electron Devices 11/2013; 60(11):3907-3912. · 2.36 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Microwave occupies a glorious position in the electromagnetic spectrum and in that there are a number of devices in this frequency regime which are capable of high power operations. Among them, gyrotron has proven to be an efficient source for radio frequency (RF) generation at high power level and up to very high frequency. The gyrotron consists of several components like electron beam source, interaction structure, quasi-optical launcher, collector, RF window, magnet system, etc. All the components have their distinct role in the function of the device. Among them, electron beam source also called magnetron injection gun (MIG) is the generator of electron beam and it is very essential that MIG should produce and provide electron beam suitable for the beam-wave interaction at the interaction structure for the effective power growth. The paper presents the introduction of a microwave tube, gyrotron and its components alongwith review of the previous work, the background and the applications. The functions of various components of a gyrotron are discussed with particular highlighting on the electron beam emission from the electron beam source and the beam-wave interaction for power growth in the device. A review on different types of gyrotron electron beam sources is also presented.
    Journal of Fusion Energy 01/2012; · 1.20 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents the design of 28 GHz, 200 kW gyrotron for Indian TOKAMAK system. The paper reports the designs of interaction cavity, magnetron injection gun and RF window. EGUN code is used for the optimization of electron gun parameters. TE03 mode is selected as the operating mode by using the in-house developed code GCOMS. The simulation and optimization of the cavity parameters are carried out by using the Particle-in-cell, three dimensional (3-D)-electromagnetic simulation code MAGIC. The output power more than 250 kW is achieved.
    Frequenz -Berlin- 01/2013; 67(1-2):35-42. · 0.34 Impact Factor