Simulation of Secondary Electron and Backscattered Electron Emission in A6 Relativistic Magnetron Driven by Different Cathode

Prticle-in-cell(PIC) simulations demonstrated that,when the relativistic magnetron with diffraction output(MDO) is applied with a 410 kV voltage pulse,or when the relativistic magnetron with radial output is applied with a 350 kV voltage pulse,electrons emitted from the cathode with high energy will strike the anode block wall.The emitted secondary electrons and backscattered electrons affect the interaction between electrons and RF fields induced by the operating modes,which decreases the output power in the radial output relativistic magnetron by about 15%(10%for the axial output relativistic magnetron),decreases the anode current by about 5%(5%for the axial output relativistic magnetron),and leads to a decrease of electronic efficiency by 8%(6%for the axial output relativistic magnetron).The peak value of the current formed by secondary and backscattered current equals nearly half of the amplitude of the anode current,which may help the growth of parasitic modes when the applied magnetic field is near the critical magnetic field separating neighboring modes.Thus,mode competition becomes more serious.     

Optimal Matching of Magnetic Pulse Compressor

Energy transmission efficiency in the magnetic pulse generators varies with saturated time of magnetic switch. An optimal matching time exists and depends on the compression ratio, under which, the energy transmission efficiency can reach approximate 100%. The equation of required magnetic core volume is obtained by taken into account the optimal matching mode. It indicates that a great reduction on the volume is feasible under the optimal matching mode. The circuit simulation code-PSPICE is also introduced to simulate a 3-stage magnetic pulse compressor, and the results are in accordance with those of equivalent circuit analyses.     

AC-PDP新型驱动电路的设计与实现

本文针对现有AC-PDP驱动电路产生波形不够灵活的缺点，基于隔离变压器耦合的思想，采用模块化、层次化的设计方法，设计并实现了一种新型的驱动电路。     

带有浮动电极的等离子体显示板发光效率数值模拟研究

针对表面放电AC PDP中一种大放电间隙的情形，采用流体模拟方法，研究浮动电极的宽度、间隙以及浮动电极与显示电极平面之间的介质厚度及其相对介电常数对发光效率的影响，结果发现浮动电极的宽度和间隙对发光效率影响较大，而浮动电极与显示电极平面之间的介质厚度及其相对介电常数则对发光效率影响较小，采用浮动电极后最小维持电压得到了较大幅度的降低。     

采用自适应有限灰度级子场编码方法提高等离子体显示器的显示质量

为了改善等离子体显示器的动态显示质量,在减轻动态假轮廓的同时提高灰度显示质量,提出了基于直方图均衡化的自适应有限灰度级子场编码方法。该方法首先对输入图像进行直方图均衡化,在灰度"均匀分布"的新直方图上,按子场的数目平均划分灰度区间,选取每个区间中间的灰度级作为预采样灰度级;然后将预采样灰度级按照直方图均衡化的反函数进行映射,得到采样灰度级和子场编码。为了达到更好的灰度显示效果,在累积式灰度编码中,依次限定单个子场编码为零,从而得到更多的显示灰度级。仿真实验结果表明,该方法能在动态假轮廓改善和灰度级表现能力之间取得平衡,在减轻动态假轮廓的同时弥补了"累积式"发光显示灰度级不足的问题,得到了较好的显示效果。     

非均匀扇形磁场三阶象差系数的计算机辅助推导

利用自行研制的软件包推导出非均匀扇形磁场所有三阶象差系数的具体解析表达式。纠正了国外学者手工推导的径向三阶象差系数的６项错误。首次推导出了非均匀扇形磁场的轴向三阶象差系数。     

新型彩色交流等离子体显示器的研究

在充分了解与研究现有技术的基础上,设计出了结构新颖、性能良好的新的PDP结构,以及与之配合的工作方式和驱动方法,据此制作了实验屏,获得了良好结果.     

AC-PDP放电特性参量及其测量

根据气体放电特性和交流等离子体显示器的放电单元结构,提出了AC-PDP等效电路模型和表征该模型的3个特性参量:击穿电压、气体维持放电的最小电压和放电单元电容比.通过分析放电过程,推导出最大维持电压、最小维持电压和维持电压余裕度的表达式.利用外接串联电容,提出一种放电特性参量的测量方法,并对12英寸PDP实验屏进行实际测量,获得了放电特性参量的测量结果.本文所提放电特性参量及其测量方法对AC-PDP显示屏的放电单元设计具有参考作用.     

浮动电极对PDP单元放电最小维持电压及发光效率的影响

针对一种带有浮动电极的新型PDP单元结构,采用流体模型系统地研究了浮动电极的宽度、间隙以及浮动电极与显示电极平面之间的介质厚度及其相对介电常数对最小维持电压和发光效率的影响,结果发现(1)采用浮动电极后最小维持电压得到了较大幅度的降低;(2)发光效率高,则最小维持电压也高;(3)通过调整浮动电极的间隙,可以实现较高的发光效率,并且最小维持电压增加较少;(4)浮动电极间隙的效率指数最高(发光效率改变量/最小维持电压改变量),而浮动电极与显示电极平面之间介质厚度的效率指数最低.     

Breakdown Voltage Research of Penning Gas Mixture in Plasma Display Panel

Paschen law and equations, which ignore the influence of the Penning ionization on the electron ionization coefficient （α）, are always used as the approximation of the breakdown voltage criterion of the Penning gas mixture in current researches of discharge characteristics of the plasma display panel （PDP）. It is doubtful that whether their results match the facts. Based on the Townsend gas self-sustaining discharge condition and the chemical kinetics analysis of the Penning gas mixture discharging in PDP, the empirical equation to describe the breakdown of the Penning gas mixture is given. It is used to calculate the breakdown voltage curves of Ne-Xe/MgO and Ne-Ar/MgO in a testing macroscopic discharge cell of AC-PDP. The effective secondary electron emission coefficients （γeff） of the MgO protective layers are derived by comparing the breakdown voltage curves obtained from the empirical equation with the experimental data of breakdown voltages. In comparison with the results calculated by the Paschen law and the equation which ignore the influence of the Penning ionization on α , the results calculated by the empirical equation have better conformity with experimental data. The empirical equation characterizes the breakdown of the Penning gas mixture in PDP effectively, and gives a convenient way to study its breakdown characteristics and the secondary electron emission behaviors.