【作者】 白现臣；

【导师】 张建德； 杨建华；

【作者基本信息】 国防科学技术大学 ， 物理电子学， 2007， 硕士

【摘要】 获得更高峰值功率是高功率微波(HPM)技术的首要发展趋势,然而HPM在高峰值功率产生方面出现了脉冲缩短、脉冲功率源与微波源的阻抗匹配矛盾等物理和技术障碍。微波功率合成技术作为一种产生更高功率微波较为乐观、可行的途径,可以在一定程度上避免脉冲缩短物理障碍,但是也存在相位控制及阵元同步激励难以实现的技术问题,而且不能解决阻抗匹配矛盾。本文针对上述问题,提出了利用单脉冲功率源驱动高功率多电子束来产生多束微波,再经过功率合成获得更高功率微波的方案。作为该方案的前期研究,论文对单台加速器驱动双阴极二极管产生的强流同步双电子束进行了理论分析、粒子模拟和实验研究。论文首先利用PIC软件对无磁场约束的强流双电子束进行了模拟,结果显示:(1)在阴阳极间输入电压为442.6kV时,双电子束流值分别为23.6kA和24.0kA,总电功率约20GW,双束流达到峰值的同步精度小于6ns,理论上可获得同步高功率双电子束;(2)双电子束在单漂移管中传输时,双束间存在空间电势叠加效应和电磁力相互吸引作用。同时,对双电子束在各种磁场控制模式下的双漂移管中的传输特性进行了模拟研究,提出了选择双束控制磁场方式的两点依据,确定采用双阴极分别深入到双漂移管磁场均匀区的双螺线管控制方案。其次,在粒子模拟的基础上,对所需螺线管进行了理论和工程设计,绕制和测试了两个螺线管,同时设计并搭建了双电子束磁场控制系统。最后,对单台加速器驱动的双阴极二极管进行了实验研究。(1)强流双电子束轰击目击靶实验结果表明:在二极管电压为442.8 kV时,束流值总和为48.8 kA;双阴极二极管能够产生高功率双电子束,双束总电功率21GW,与模拟结果一致。(2)在同步双电子束实验中,利用所设计法拉第筒对双束流参数进行了诊断,实验结果表明:在二极管电压约210 kV时,双束流值分别为4.55 kA和4.37 kA;双阴极二极管能够产生高同步双电子束,双束同步精度在4～6ns之内,与模拟结果符合较好。(3)磁场引导环形双电子束实验结果显示:空心双阴极在二极管电压约380kV时,双环形束流值分别为5.10kA和4.92 kA;所设计磁场系统能够对环形双电子束进行有效约束,有效约束磁场强度约为0.5T。更多还原

【Abstract】 To obtain higher output power is an important development trend of the high power microwave. However, high power microwave sources face the physical barrier of pulse shortening and the technical trouble of impedance matching contradiction of pulse power supply. As a quite optimistic and feasible way, microwave power combination can avoid pulse shortening barrier to some extent, but it cannot overcome the impedance matching contradiction or the synchro-control problem for array elements. In the thesis, a scheme is presented as follows. Firstly, multi-beam electrons are synchronally produced by utilizing one accelerator. Then multi-beam microwave is generated by the multi-beam electrons. At last, the higher power microwave is obtained by means of power combination of the multi-beam microwave. As a primary research, the intensive synchronal dual-beam electrons generated by one accelerator was studied.Firstly, PIC simulation on the dual-cathode diode without confining magnetic field was presented with diode impedance of 10Ωand input voltage of 442.6kV. The results shows that a total beam of 47.6kA, gross power of 20GW, and synchronization precision less than 6ns has been obtained. When dual-beam transmits in a single drift tube, the effects of space electric potential superposition and significant electromagnetic interaction exist between the dual-beam electrons. At the same time, simulation investigation on the transmission characteristics of dual-beam current in dual-drift tube under various control magnetic field modes was presented.Secondly, according to the above simulation results, a control magnetic field mode by using double confining magnetic field solenoides and letting the dual-cathode go deeply into the drift tube where the magnetic field is more symmetrical was adopted. Then, the control magnetic field system for dual-beam was constructed.Finally, the experiment research on dual-beam electrons was presented based on the PIC simulation results. The experimental result of dual-beam electrons bombarding the witness target indicates that, at diode voltage of 442.8kV, total beam of 48.8kA, gross power of 21GW were obtained. The parameters of dual-beam currents were measured with the Faraday cups in the synchronization experiment, and synchronization precision of 4～6 ns was obtained. The experimental result is in a good agreement with the simulation one. Moreover, the experiment of dual-magnetic field solenoids controlling annular dual-beam current was presented. When diode voltage was 380 kV, total beam of 10 kA and effective confining magnetic density of 0.5 Tesla was obtained.更多还原