An X-band magnetically insulated transmission line oscillator （MILO） is designed and investigated numerically and experimentally for the first time. The X-band MILO is optimized in detail with KARAT code. In simulat...An X-band magnetically insulated transmission line oscillator （MILO） is designed and investigated numerically and experimentally for the first time. The X-band MILO is optimized in detail with KARAT code. In simulation, the X-band MILO, driven by a 720 kV, 53 kA electron beam, comes to a nonlinear steady state in 4.0 ns. High-power microwaves （HPM） of TEM mode is generated with an average power of 4.1 GW, a frequency of 9.3 GHz, and power conversion efficiency of 10.870 in durations of 0-40 ns. The device is fabricated according to the simulation results. In experiments, when the voltage is 400 kV and the current is 50 kA, the radiated microwave power reaches about 110 MW and the dominating frequency is 9.7GHz. Because the surfaces of the cathode end and the beam dump are destroyed, the diode voltage cannot increase continuously. However, when the diode voltage is 400 kV, the average power output is obtained to be 700 MW in simulation. The impedance of the device is clearly smaller than the simulation prediction. Moreover, the duration of the microwave pulse is obviously shorter than that of the current pulse. The experimental results are greatly different from the simulation predictions. The preliminary analyses show that the generations of the anode plasma, the cathode flare and the anode flare are the essential cause for the remarkable deviation of the experimental results from the simulation predictions.展开更多
In order to enhance the power capacity, an improved Ku-band magnetically insulated transmission line oscillator （MILO） with overmoded slow-wave-structure （SWS） is proposed and investigated numerically and experime...In order to enhance the power capacity, an improved Ku-band magnetically insulated transmission line oscillator （MILO） with overmoded slow-wave-structure （SWS） is proposed and investigated numerically and experimentally. The analysis of the dispersion relationship and the resonant curve of the cold test indicate that the devine can operate at the near π mode of the TM01 mode, which is useful for mode selection and control. In the particle simulation, the improved Ku-band MILO generates a microwave with a power of 1.5 GW and a frequency of 12.3 GHz under an input voltage of 480 kV and input current of 42 kA. Finally, experimental investigation of the improved Ku-band MILO is carried out. A high-power microwave （HPM） with an average power of 800 MW, a frequency of 12.35 GHz, and pulse width of 35 ns is generated under a diode voltage of 500 kV and beam current of 43 kA. The consistency between the experimental and simulated far-field radiation pattern confirms that the operating mode of the improved Ku-band MILO is well controlled in zc mode of the TM01 mode.展开更多
Abstract The magnetically insulated line oscillator （MILO） is a gigawatt-class, coaxial crossed-field microwave tube, which is at present a major hotspot in the field of high-power mi- crowaves （HPM） research. In ...Abstract The magnetically insulated line oscillator （MILO） is a gigawatt-class, coaxial crossed-field microwave tube, which is at present a major hotspot in the field of high-power mi- crowaves （HPM） research. In order to improve the power conversion efficiency and eliminate or at least minimize anode plasma formation in the load region and radio frequency （RF） breakdown in the slow wave structure （SWS） section, an X-band MILO is presented and inyestigated nu- merically with KARAT code. The design idea is briefly presented and the simulation results are given and discussed. In the simulation, HPM is generated with peak power of 3.4 GW, maximum electric field of about 1 MV/cm, and peak power conversion efficiency of 14.0%, when the voltage is 559.1 kV and the current is 43.2 kA. The microwave frequency is pure and falls in the X-band of 9.0 GHz. The theoretical investigation and the simulation results are given to prove that the anode plasma formation and the RF breakdown can be effectively avoided or at least minimized, respectively.展开更多
根据磁绝缘线振荡器(magnetically insulated transmission line oscillator,MILO)中基模(TM_(00)模)与临近高阶模(HEM_(11)模)高频场分布的区别,采用破坏各腔之间HEM_(11)模π模谐振条件的方式抑制器件中高阶模产生的方法,提出了高阶...根据磁绝缘线振荡器(magnetically insulated transmission line oscillator,MILO)中基模(TM_(00)模)与临近高阶模(HEM_(11)模)高频场分布的区别,采用破坏各腔之间HEM_(11)模π模谐振条件的方式抑制器件中高阶模产生的方法,提出了高阶模抑制型MILO.运用三维全电磁粒子模拟软件对高阶模抑制型L波段MILO器件进行模拟研究,数值模拟结果表面该方法能够抑制器件中HEM_(11)模的产生.在此基础上对器件进行了对比性实验研究,实验结果表明高阶模抑制型器件能够抑制HEM_(11)模的产生,稳定工作在基模.展开更多
基金supported by the Chinese National Natural Science Foundation (Grant No 10675168)Innovation Fund of Graduate School of the National University of Defense Technology of China
文摘An X-band magnetically insulated transmission line oscillator （MILO） is designed and investigated numerically and experimentally for the first time. The X-band MILO is optimized in detail with KARAT code. In simulation, the X-band MILO, driven by a 720 kV, 53 kA electron beam, comes to a nonlinear steady state in 4.0 ns. High-power microwaves （HPM） of TEM mode is generated with an average power of 4.1 GW, a frequency of 9.3 GHz, and power conversion efficiency of 10.870 in durations of 0-40 ns. The device is fabricated according to the simulation results. In experiments, when the voltage is 400 kV and the current is 50 kA, the radiated microwave power reaches about 110 MW and the dominating frequency is 9.7GHz. Because the surfaces of the cathode end and the beam dump are destroyed, the diode voltage cannot increase continuously. However, when the diode voltage is 400 kV, the average power output is obtained to be 700 MW in simulation. The impedance of the device is clearly smaller than the simulation prediction. Moreover, the duration of the microwave pulse is obviously shorter than that of the current pulse. The experimental results are greatly different from the simulation predictions. The preliminary analyses show that the generations of the anode plasma, the cathode flare and the anode flare are the essential cause for the remarkable deviation of the experimental results from the simulation predictions.
基金Project supported partly by the National Natural Science Foundation of China(Grant No.61171021)
文摘In order to enhance the power capacity, an improved Ku-band magnetically insulated transmission line oscillator （MILO） with overmoded slow-wave-structure （SWS） is proposed and investigated numerically and experimentally. The analysis of the dispersion relationship and the resonant curve of the cold test indicate that the devine can operate at the near π mode of the TM01 mode, which is useful for mode selection and control. In the particle simulation, the improved Ku-band MILO generates a microwave with a power of 1.5 GW and a frequency of 12.3 GHz under an input voltage of 480 kV and input current of 42 kA. Finally, experimental investigation of the improved Ku-band MILO is carried out. A high-power microwave （HPM） with an average power of 800 MW, a frequency of 12.35 GHz, and pulse width of 35 ns is generated under a diode voltage of 500 kV and beam current of 43 kA. The consistency between the experimental and simulated far-field radiation pattern confirms that the operating mode of the improved Ku-band MILO is well controlled in zc mode of the TM01 mode.
基金supported by National Natural Science Foundation of China(No.11075210)the Special Financial Grant from the China Postdoctoral Science Foundation(No.201104761)
文摘Abstract The magnetically insulated line oscillator （MILO） is a gigawatt-class, coaxial crossed-field microwave tube, which is at present a major hotspot in the field of high-power mi- crowaves （HPM） research. In order to improve the power conversion efficiency and eliminate or at least minimize anode plasma formation in the load region and radio frequency （RF） breakdown in the slow wave structure （SWS） section, an X-band MILO is presented and inyestigated nu- merically with KARAT code. The design idea is briefly presented and the simulation results are given and discussed. In the simulation, HPM is generated with peak power of 3.4 GW, maximum electric field of about 1 MV/cm, and peak power conversion efficiency of 14.0%, when the voltage is 559.1 kV and the current is 43.2 kA. The microwave frequency is pure and falls in the X-band of 9.0 GHz. The theoretical investigation and the simulation results are given to prove that the anode plasma formation and the RF breakdown can be effectively avoided or at least minimized, respectively.
文摘根据磁绝缘线振荡器(magnetically insulated transmission line oscillator,MILO)中基模(TM_(00)模)与临近高阶模(HEM_(11)模)高频场分布的区别,采用破坏各腔之间HEM_(11)模π模谐振条件的方式抑制器件中高阶模产生的方法,提出了高阶模抑制型MILO.运用三维全电磁粒子模拟软件对高阶模抑制型L波段MILO器件进行模拟研究,数值模拟结果表面该方法能够抑制器件中HEM_(11)模的产生.在此基础上对器件进行了对比性实验研究,实验结果表明高阶模抑制型器件能够抑制HEM_(11)模的产生,稳定工作在基模.
