Abstract
The parasitic oscillation of the TE{sup o}{sub 21} gyrotron Backward Wave (gyro BW) mode is observed in a low-Q, 8 GHz TE{sup o}{sub 011} gyrotron. Although at low power (P{sub BW}<5 kW), the oscillation of the gyro BW mode, simultaneously with the gyrotron mode, results in a maximum TE{sup o}{sub 011} mode efficiency of less than 0.25. The parasitic oscillation is suppressed by operating the gyrotron with a negative magnetic field gradient along the electron beam, which allows the maximum efficiency to reach 0.40 and the output power to be multiplied by a factor varying from 1.4 to 1.7. The optimum efficiency curve of the TE{sup o}{sub 011} mode indicates that the low-Q cavity behaves as a much higher Q{sub diff} cavity. Too large magnetic field gradient and {alpha} values favour the TE{sup o}{sub 012} longitudinal mode, which oscillates in place of the TE{sup o}{sub 011} mode and limits its maximum output power. This competitive process is responsible for the high-Q like output power. (author) 14 figs., 14 refs.
Muggli, P;
Tran, M Q;
Tran, T M
[1]
- Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP)
Citation Formats
Muggli, P, Tran, M Q, and Tran, T M.
Parasitic oscillation in and suppression of a gyro BW mode in a low-Q 8 GHz gyrotron.
Switzerland: N. p.,
1991.
Web.
Muggli, P, Tran, M Q, & Tran, T M.
Parasitic oscillation in and suppression of a gyro BW mode in a low-Q 8 GHz gyrotron.
Switzerland.
Muggli, P, Tran, M Q, and Tran, T M.
1991.
"Parasitic oscillation in and suppression of a gyro BW mode in a low-Q 8 GHz gyrotron."
Switzerland.
@misc{etde_10132899,
title = {Parasitic oscillation in and suppression of a gyro BW mode in a low-Q 8 GHz gyrotron}
author = {Muggli, P, Tran, M Q, and Tran, T M}
abstractNote = {The parasitic oscillation of the TE{sup o}{sub 21} gyrotron Backward Wave (gyro BW) mode is observed in a low-Q, 8 GHz TE{sup o}{sub 011} gyrotron. Although at low power (P{sub BW}<5 kW), the oscillation of the gyro BW mode, simultaneously with the gyrotron mode, results in a maximum TE{sup o}{sub 011} mode efficiency of less than 0.25. The parasitic oscillation is suppressed by operating the gyrotron with a negative magnetic field gradient along the electron beam, which allows the maximum efficiency to reach 0.40 and the output power to be multiplied by a factor varying from 1.4 to 1.7. The optimum efficiency curve of the TE{sup o}{sub 011} mode indicates that the low-Q cavity behaves as a much higher Q{sub diff} cavity. Too large magnetic field gradient and {alpha} values favour the TE{sup o}{sub 012} longitudinal mode, which oscillates in place of the TE{sup o}{sub 011} mode and limits its maximum output power. This competitive process is responsible for the high-Q like output power. (author) 14 figs., 14 refs.}
place = {Switzerland}
year = {1991}
month = {Dec}
}
title = {Parasitic oscillation in and suppression of a gyro BW mode in a low-Q 8 GHz gyrotron}
author = {Muggli, P, Tran, M Q, and Tran, T M}
abstractNote = {The parasitic oscillation of the TE{sup o}{sub 21} gyrotron Backward Wave (gyro BW) mode is observed in a low-Q, 8 GHz TE{sup o}{sub 011} gyrotron. Although at low power (P{sub BW}<5 kW), the oscillation of the gyro BW mode, simultaneously with the gyrotron mode, results in a maximum TE{sup o}{sub 011} mode efficiency of less than 0.25. The parasitic oscillation is suppressed by operating the gyrotron with a negative magnetic field gradient along the electron beam, which allows the maximum efficiency to reach 0.40 and the output power to be multiplied by a factor varying from 1.4 to 1.7. The optimum efficiency curve of the TE{sup o}{sub 011} mode indicates that the low-Q cavity behaves as a much higher Q{sub diff} cavity. Too large magnetic field gradient and {alpha} values favour the TE{sup o}{sub 012} longitudinal mode, which oscillates in place of the TE{sup o}{sub 011} mode and limits its maximum output power. This competitive process is responsible for the high-Q like output power. (author) 14 figs., 14 refs.}
place = {Switzerland}
year = {1991}
month = {Dec}
}