Higher mode excitation is very serious in the relativistic klystron amplifier, especially for the high gain relativistic amplifier working at tens of kilo-amperes. The mechanism of higher mode excitation is explored i...Higher mode excitation is very serious in the relativistic klystron amplifier, especially for the high gain relativistic amplifier working at tens of kilo-amperes. The mechanism of higher mode excitation is explored in the FIC simulation and it is shown that insufficient separation of adjacent cavities is the main cause of higher mode excitation. So RF lossy material mounted on the drift tube wall is adopted to suppress higher mode excitation. A high gain S-band relativistic klystron amplifier is designed for the beam current of 13 kA and the voltage of 1 MV. PIC simulation shows that the output power is 3.2 GW when the input power is only 2.8 kW.展开更多
In order to overcome the disadvantages of conventional high frequency relativistic klystron amplifiers in power capability and RF conversion efficiency, a C-band relativistic extended interaction klystron amplifier wi...In order to overcome the disadvantages of conventional high frequency relativistic klystron amplifiers in power capability and RF conversion efficiency, a C-band relativistic extended interaction klystron amplifier with coaxial output cavity is designed with the aid of PIC code MAGIC. In the device, disk-loaded cavities are introduced in the input and intermediate cavity to increase the beam modulation depth, and a coaxial disk-loaded cavity is employed in the output cavity to enhance the RF conversion efficiency. In PIC simulation, when the beam voltage is680 k V and current is 4 k A, the device can generate 1.11 GW output power at 5.64 GHz with an efficiency of 40.8%.展开更多
The RF input cavity is an important component for velocity-modulating types of microwave device, providing velocity modulation and density modulation. Conventional RF input cavities, however, encounter the problem of ...The RF input cavity is an important component for velocity-modulating types of microwave device, providing velocity modulation and density modulation. Conventional RF input cavities, however, encounter the problem of power capacity in the high frequency band due to the scaling law of the working frequency and device size. In this paper, an X-band overmoded input cavity is proposed and investigated. A resonant reflector is employed to reflect the microwave and isolate the input cavity from the diode and RF extractor. The resonant property of the overmoded input cavity is proved by simulations and cold tests, with PIC simulation showing that with a beam voltage of 600 kV and current of 7 kA, an input power of 90 kW is sufficient to modulate the beam with a modulation depth of 3%.展开更多
基金Supported by National Natural Science Foundation of China(61271109)
文摘Higher mode excitation is very serious in the relativistic klystron amplifier, especially for the high gain relativistic amplifier working at tens of kilo-amperes. The mechanism of higher mode excitation is explored in the FIC simulation and it is shown that insufficient separation of adjacent cavities is the main cause of higher mode excitation. So RF lossy material mounted on the drift tube wall is adopted to suppress higher mode excitation. A high gain S-band relativistic klystron amplifier is designed for the beam current of 13 kA and the voltage of 1 MV. PIC simulation shows that the output power is 3.2 GW when the input power is only 2.8 kW.
文摘In order to overcome the disadvantages of conventional high frequency relativistic klystron amplifiers in power capability and RF conversion efficiency, a C-band relativistic extended interaction klystron amplifier with coaxial output cavity is designed with the aid of PIC code MAGIC. In the device, disk-loaded cavities are introduced in the input and intermediate cavity to increase the beam modulation depth, and a coaxial disk-loaded cavity is employed in the output cavity to enhance the RF conversion efficiency. In PIC simulation, when the beam voltage is680 k V and current is 4 k A, the device can generate 1.11 GW output power at 5.64 GHz with an efficiency of 40.8%.
基金Supported by Talent Introduction Profect of Sichuan University of Science and Engineering(2013 RC09)
文摘The RF input cavity is an important component for velocity-modulating types of microwave device, providing velocity modulation and density modulation. Conventional RF input cavities, however, encounter the problem of power capacity in the high frequency band due to the scaling law of the working frequency and device size. In this paper, an X-band overmoded input cavity is proposed and investigated. A resonant reflector is employed to reflect the microwave and isolate the input cavity from the diode and RF extractor. The resonant property of the overmoded input cavity is proved by simulations and cold tests, with PIC simulation showing that with a beam voltage of 600 kV and current of 7 kA, an input power of 90 kW is sufficient to modulate the beam with a modulation depth of 3%.
