低磁场S波段相对论返波振荡器模拟与实验

Simulation and experiment of S-band relativistic backward wave oscillator with low magnetic field

为实现高功率微波(HPM)系统的小型化,设计一个S波段较低磁场相对论返波管(RBWO)振荡器。针对低磁场特点,分析慢波结构、引导磁场、束压、束流等对输出微波的影响,通过模拟软件(PIC)优化结构。以此设计引导磁场为0.24 T,电子束束压为725 kV,束流为6 kA,频率为3.53 GHz,输出微波功率为1.22 GW,束波转换效率为27%的低磁场S波段相对论返波管。仿真实验结果表明:在强流电子束加速器平台上外加磁场为0.24 T时,得到平均功率1 GW、频率3.58 GHz、脉宽90 ns的微波输出,与理论值一致。进行了重频为1 Hz,20 s的稳定性实验,该实验结果为实现相对论返波管的永磁包装奠定了良好的基础。

An S-band Relativistic Backward Wave Oscillator(RBWO)with lower magnetic field is designed in order to achieve the miniaturization of High-Power Microwave(HPM)systems.According to the characteristics of low magnetic field,the effects of slow wave structure,guided magnetic field,beam pressure,beam current,etc.on the output microwave are analyzed.The structure is optimized by using particle simulation software.On this basis,a low magnetic field S-band relativistic backward wave tube is designed,which has a guided magnetic field of 0.24 T,an electron beam voltage of 725 kV,a beam current of 6 kA,a frequency of 3.53 GHz,an output microwave power of 1.22 GW and a beam conversion efficiency of 27%.The preliminary experiment is performed on the accelerator platform with high current electron beam when the external magnetic field is 0.24 T.The microwave is output with average power of 1 GW,3.58 GHz frequency and 90 ns pulse width.And a stability test at 1 Hz repetition frequency in 20 s is performed.The experimental results have laid a good foundation for realizing the relativistic backward wave tube of the permanent magnet packaging.