title: Dynamics of mode competition in the gyrotron backward-wave oscillator.
abstract: The axial modes of the gyrotron backward-wave oscillator (gyro-BWO) each exhibit a distinctive asymmetry in axial field profile. As a result, and in sharp contrast to the behavior of the familiar resonator-based gyrotron oscillator, particle simulations of the gyro-BWO reveal a radically different pattern of mode competition in which a fast-growing and well-established mode is subsequently suppressed by a later-starting mode with a more favorable field profile. This is verified in a Ka-band experiment and the interaction dynamics are elucidated with a time-frequency analysis.
authors.affiliation: Department of Physics, National Tsing Hua University, Hsinchu, Taiwan.
authors.forename: K F
authors.initials: KF
authors.lastname: Pao
authors.forename: T H
authors.initials: TH
authors.lastname: Chang
authors.forename: C T
authors.initials: CT
authors.lastname: Fan
authors.forename: S H
authors.initials: SH
authors.lastname: Chen
authors.forename: C F
authors.initials: CF
authors.lastname: Yu
authors.forename: K R
authors.initials: KR
authors.lastname: Chu