旭日型相对论磁控管的三维仿真研究

【作者】 赵静；

【导师】 刘盛纲；

【作者基本信息】 电子科技大学 ， 电子科学与技术， 2011， 硕士

【摘要】 粒子模拟软件CHIPIC是由我国自主研发的,相对于同类粒子模拟软件,具有图形建模和并行运算的优势。本文在验证CHIPIC软件模拟旭日型相对论磁控管可行的基础上,应用粒子模拟软件CHIPIC对旭日型相对论磁控管进行了并行运算及优化的三维仿真研究。首先,分别应用国外先进软件和CHIPIC软件对旭日型相对论磁控管进行了建模,并在同样的参数下模拟。对比模拟结果,从而验证CHIPIC软件模拟旭日型相对论磁控管的可行性。分析了CHIPIC软件中三种算法时偏法、高品质因素法、中心差分法对于旭日型相对论磁控管模拟计算的优劣,最终本文采用了高品质因素算法。接着,在旭日型相对论磁控管中应用粒子模拟软件CHIPIC进行了并行运算,分析了运算时间与并行计算机台数的关系,从而减少运算时间,加快运算速度。当迭代时间为50ns时,运算时间从单台计算机(双核Intel core,CPU 3.00GHz,内存3.25GB)的26.5小时运算时间,减小到6台计算机并行运算的10.6小时。最后,通过不断地改变旭日型相对论磁控管的结构参数及运行参数,探讨他们对管子振荡,输出功率和效率的影响。模拟发现:(1)调节阴极支撑杆可以有效地提高工作模式π模的起振速度;(2)一定范围内,随着阴极半径的减少,旭日型相对论磁控管的输出功率、效率在增大;(3)一定范围内,随着阴极长度的减少,工作电流在减少,输出效率增大;(4)调整小腔深度,可以平衡大小腔的深度比,选择适中的深度,从而平衡零模分量和模式隔离度的影响;(5)耦合角度的增大有利于降低Q值,从而提高耦合输出的功率,但到一定程度,Q值随耦合角的变化很小;(6)通过对外加电压和磁场的调节,发现工作点在接近同步条件曲线附近的位置得到的输出功率和效率较好。在分析了以上影响因素后,对旭日型相对论磁控管进行了优化,模拟结果表明:当外加电压为750kV,磁场为0.68T时,在2.7GHz的工作频率下,管子的输出功率达到2.6GW,输出效率达到23.7%,起振时间为16ns。更多还原

【Abstract】 The particle simulation software of CHIPIC is self-developed by China, compared to similar particle simulation software, which has the advantage of graphical modeling and parallel computing. Based on the feasibility of simulating rising-sun relativistic magnetron by CHIPIC software, the rising-sun relativistic magnetron is simulated in 3D and researched on the parallel computing and optimization by the particle simulation software of CHIPIC.Firstly, the rising-sun relativistic magnetron is modeled and simulated in the same parameters by using the advanced software abroad and CHIPIC software respectively. Then, compared to the simulation results, verify the feasibility of CHIPIC software to simulate rising-sun relativistic magnetron. Analyze the pros and cons of three algorithms in CHIPIC, which is time-biased, high-Q, centered-difference respectively, for simulating the rising-sun relativistic magnetron, and ultimately this paper applies the high-Q algorithm.Secondly, the parallel computing of particle simulation software CHIPIC is applied in rising-sun relativistic magnetron, and analyze the relationship between the computational speed and the number of parallel computer, thereby reducing the computation time, speeding up the computation speed. When the iteration time is 50ns, the computing time reduces from 26.5 hours in a single computer (dual-core Intel core, CPU 3.00GHz, RAM 3.25GB) to 10.6 hours of parallel computing in six computers.Finally, discuss the effect of structure and operating parameters of the rising-sun relativistic magnetron for the oscillations, output power and efficiency by constantly changing them. Simulation found that: (1) adjusting the cathode-stem can effectively improve the startup speed ofπmode; (2)within a certain range, with the reduction of the cathode radius, the rising-sun relativistic magnetron’s output power and efficiency both increase; (3)within a certain range, with the reduction of the cathode length, the operating current reduces and the output efficiency increases; (4)adjusting the depth of the small cavity can balance depth ratio of the big-small cavity, choosing a moderate depth can balance the impact of zero-mode component and mode isolation; (5)the increase of the coupling angle helps reduce the Q value, thereby enhancing the output power coupled, however, to a certain extent, Q value changes little with the coupling angle changing; (6)through the regulation of the applied voltage and magnetic fields, we found the output power and efficiency is better when the operating point is near the curve of synchronization conditions. Based the analysis of above factors, the rising-sun relativistic magnetron has been optimized, the simulation results show that: when the applied voltage is 750kV, the magnetic field is 0.68T, the tube output power reaches 2.6GW and the output efficiency to 23.7%, start-up time is 16ns in the frequency of 2.7GHz.更多还原