向内发射同轴虚阴极振荡器的优化

为提高虚阴极振荡器微波能量转换效率,使用2.5维全电磁P IC(particle in ce ll)软件对向内发射同轴虚阴极振荡器进行数值模拟,优化设计了阳极反射板与阴极发射区之间距离D,并研究了阳极网透射区宽度B对能量转换效率的影响。模拟发现:选取适当的D值可提高效率,同时随着B的增大,能量转换效率逐渐增大并趋近一稳定值。模拟所得微波振荡主频与理论值符合较好。优化结果为:在阴、阳极半径分别为7 cm和5.5 cm,二极管电压250 kV,电流20 kA条件下,得到主频3.45 GH z,3 dB带宽约3%,微波功率310MW,能量转换效率6.8%的窄带微波输出。

Optimization of an inward-emitting coaxial vircator

An inward-emitting coaxial vircator was simulated numerically using a code 2.5 dimension PIC(partical in cell) to optimize the structural parameters and to enhance the energy conversion efficiency.The simulation optimizes the distance D between the anode reflector and the center of the emission area on the cathode.The influence of the transparency width B of the anode foil on the efficiency was also studied.The results show that higher efficiencies can be obtained by choosing appropriate D values and that the efficiency increases gradually with increasing B.The dominant frequency is consistent with theoretical predictions.The optimized result has a dominant frequency of 3.45 GHz with 3% bandwidth(3 dB),a power of 310 MW,and a conversion efficiency of 6.8% with a cathode radius of 7 cm,an anode radius of 5.5 cm,a diode voltage of 250 kV,and a current of 20 kA.