H. H. Song, D. B. McDermott, Y. Hirata, L. R. Barnett, C. W. Domier, H. L. Hsu, T. H. Chang, W. C. Tsai, K. R. Chu and N. C. Luhmann Jr., “Theory and Experiment of a 94 GHz Gyrotron Traveling-Wave Amplifier,” Physics of Plasmas, Vol. 11, No. 5, 2004, pp. 2935-2941. doi:10.1063/1.1690764

has been cited by the following article:

• TITLE: Calculation of Start-Oscillation-Current for Lossy Gyrotron Traveling-Wave Tube (Gyro-TWT) Using Linear Traveling-Wave Tube (TWT) Parameter Conversions

  AUTHORS: Heather H. Song

  KEYWORDS: Start-Oscillation-Current; Gyro-TWT; TWT; Lossy; Stable; Competing Mode

  JOURNAL NAME: Journal of Electromagnetic Analysis and Applications, Vol.5 No.1, January 23, 2013

  ABSTRACT: The start-oscillation-current of a gyro-TWT (gyrotron traveling-wave tube) determines the stable operating current level of the device. The amplifier is susceptible to oscillations when the operating current level is higher than the start-oscillation current. There are several ways of calculating the start-oscillation current, including using the linear and nonlinear theory of a gyro-TWT. In this paper, a simple way of determining the start-oscillation current of lossy gyro-TWT is introduced. The linear TWT parameters that include the effects of synchronism, loss, and gain, were converted to gyro-TWT parameters to calculate the start-oscillation-current. The dependence on magnetic field, loss, and beam alpha was investigated. Calculations were carried out for a V-band gyro-TWT for both operating and competing modes. The proposed method of calculating the start-oscillation current provides a simple and fast way to estimate the oscillation conditions and can be used for the design process of a gyro-TWT.