基于速调管2.5维粒子模型的非线性注波互作用的研究  

The Nonlinear Beam-wave Interaction of High Power Klystrons Based on a 2.5-Dimensional Particle-in-cell Model

作　　者：高冬平[1,2] 丁耀根[1] 刘濮鲲[1] 杜朝海[1,2] 赵鼎[1] 

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

出　　处：《电子与信息学报》2010年第10期2490-2495,共6页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(60801031);中国科学院知识创新项目资助课题

摘　　要：该文采用恰当的近似提出了速调管专用的2.5D粒子模型,并基于该模型研究速调管中复杂的非线性注波互作用过程。该模型采用粒子模拟的思想将电荷和电流恰当地分配到空间网格上,采用时域有限差分方法(FDTD)求解麦克斯韦方程组以精确解出电子注的空间电荷场,采用端口近似方法模拟高频谐振腔场对电子注的影响,最后基于洛伦兹力方程求解电磁场对粒子的推动作用。该模型首次将FDTD和端口近似方法结合起来,能够比传统的1维非线性模型更加精确地模拟互作用的物理过程,同时又比全3维模拟方法节约计算资源。基于该物理模型编制了国内首个速调管2.5D粒子模拟程序KLY2D,并仿真了一支S波段50MW高峰值功率速调管。理论计算与实验结果一致,说明了物理模型和程序的可靠性,这对推动高功率速调管的设计和发展具有重要的推动作用。A 2.5-Dimensional（2.5D） Particle-In-Cell（PIC） model is developed to study complicated nonlinear beam-wave interaction in the high-power klystron.Firstly,the particle charge and the beam current are properly assigned onto the grid based on the concept of PIC simulation.Secondly,the Finite-Difference-Time-Domain（FDTD） method is introduced to solve Maxwell＇s equations so that the space charge of the electron beam can be accurately described.Thirdly,the port-approximation method is employed to simulate high-frequency cavity fields.Finally,the Lorentz equation is solved to further advance particle motion.The FDTD method and the port-approximation idea are combined for the first time in this model,which is more accurate than the traditional 1D nonlinear model,and,at the same time,is more efficient than the full 3D PIC method.The first domestic 2.5D particle-in-cell code,KLY2D,is developed based on this model.And an S-band 50MW high peak-power klystron is simulated using this code.The consistency between the theoretical results and the experimental results indicates the reliability of the theoretical model and the simulation code,which is of importance for further promoting the design and the development of high power klystrons.

关 键 词：速调管 时域有限差分 粒子模拟 非线性注波互作用 

分 类 号：TN122[电子电信—物理电子学]