非轴对称磁场对多级降压收集极性能的影响  

Influence of Non-Axisymmetric Magnetic Field on Characteristics of Multistage Depressed Collector

作　　者：郭际[1,2] 尚新文[3,2] 李飞[3] 肖刘[3] 刘濮鲲[1] 王书见[1,2] 

机构地区：[1]中国科学院电子学研究所中国科学院高功率微波源与技术重点实验室,北京100190 [2]中国科学院研究生院,北京100039 [3]中国科学院电子学研究所空间行波管研发中心,北京100190

出　　处：《真空科学与技术学报》2013年第8期797-802,共6页Chinese Journal of Vacuum Science and Technology

摘　　要：收集效率和回流率是体现多级降压收集极性能的两个重要指标,本文尝试在收集极表面加上一定弧度的磁钢贴片,以此在收集极内引入非轴对称磁场,通过调节磁场的大小和位置,观察磁场对收集极内电子运动轨迹的影响,寻求实现收集极效率的最大化并抑制二次电子回流。针对某一Ku波段行波管多级降压收集极,加入优化磁场后的计算结果与未加磁场时相比,各电极电流分布发生变化,部分电子被更靠后的电极所收集,中频点处回流率由原来的2.49%降低到0.54%,同时收集效率提高超过3%达到79.07%。收集极性能的改善也为行波管效率的提高提供了保证。The multistage depressed collector（MDC） of the traveling wave tube（TWT） was modified by introduction of the non-axisymmetric magnetic field,generated with a piece of magnetic steel sheet closely contacting the MDC outer wall to increase the collector efficiency and decrease the back-streaming rate.The impact of the magnetic field distribution in the MDC of a Ku-band TWT on the electron trajectories was modeled and calculated with MTSS simulation code.The simulated results show that the optimized magnetic field distribution significantly affects the current distributions on different electrodes.For instance,quite a few electrons can reach the lower potential electrode.At the middle operating frequency,the magnetic field simultaneously reduces the back-streaming rate from 2.46% to 0.54%;and increases the collector efficiency by more than 3%,up to 79.07%.

关 键 词：多级降压收集极 非轴对称磁场 收集效率 二次电子 行波管 

分 类 号：TN124[电子电信—物理电子学]