一种环形反射板结构同轴虚阴极振荡器

为了提高同轴虚阴极振荡器的能量转换效率,提出了一种环形反射板结构,在阳极箔末端采用一个环形反射板,利用自反馈微波对电子束进行预调制,增强了波-束互作用,提高了能量转换效率.2.5维粒子模拟表明,微波输出功率随反射板的位置呈周期性变化.经过对结构参数的优化,采用距离阴极发射面左端20mm、内径为25 mm的环形反射板,微波输出功率最高.在外加600 kV电压条件下,模拟得到了1.13 GW微波输出功率,其能量转换效率达到8%,频率为4.85 GHz,频谱特性好.

Study on Coaxial Vircator with Annular Anode Reflector

In order to increase the efficiency of the coaxial vircator,a new structure with the annular anode reflector is proposed.The structure adopts an annular reflector at the end of anode foil.It takes advantage of self feedback microwave to premodulate electron beam and to enhance the beam-microwave interaction,thus to increase the energy conversion efficiency.With 2.5-dimensional particle-in-cell simulation,the microwave output power depending on the position and the inner radius of the reflector is studied.It is found that the power changes periodically with the position of the reflector, and the maximum power will be obtained by adopting a reflector with 25 mm inner radius at a distance of 20 mm from the left side of the cathode emitter.Applying a 600 kV voltage to the optimized structure,output power of 1.13 GW can be achieved with an efficiency of 8% at 4.85 GHz,and has a good bandwidth characteristic.