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从均匀场电极理论出发,计算并讨论了近似Rogowski电极、Chang电极(含紧凑式Chang电极)和Ernst电极的形状、理论电场分布和实际电场分布。对实验室所用的几种电极进行了脉冲放电实验,从而获得了TEA CO2激光器的放电参数与输出特性,并对这些结果进行了比较和分析。计算表明,在基本参数相同的情况下,Ernst电极具有最紧凑的外形和最佳的均匀电场分布。实验表明,采用近似Rogowski电极的TEA CO2激光器具有最大放电辉光范围和44 kV的最小放电击穿电压;采用Ernst电极的TEA CO2激光器具有25 J的最高单脉冲能量和最大17.2%的斜率效率。最后提出了TEA CO2激光器主电极的选择建议。 相似文献
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利用矢量傅里叶变换和稳相法获得了相干点源位于光轴上任意位置时,消球差光学系统像场结构的积分表达式,详细研究了使用线偏振光照明时像平面上大物方孔径角对像场结构的影响.模拟计算表明,在像空间垂直于光轴的平面上,如果物方孔径角较大,磁场分布绕光轴旋转90°后不再与电场分布相同,电场能量密度、磁能量密度和玻印亭矢量分布的等高线始终近似为椭圆,并且物方孔径角是导致玻印亭矢量分布失去圆对称性的主要因素.同时当使用小像方孔径角时,电场能量密度分布形状的长轴方向垂直于物空间电场的振动方向;随着像方孔径角逐渐增大,电场能量密度分布形状的长轴方向将逐渐变为与物空间电场的振动方向相同.这些结论完全不同于以前理论所预测的结果.
关键词:
成像系统
像场结构
矢量傅里叶变换
稳相法 相似文献
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高电压脉冲气体开关稳定性研究 总被引:3,自引:3,他引:0
利用2MV脉冲试验装置研究了2MVSF6脉冲气体开关电极材料和电极形状对开关击穿稳定性的影响。根据光滑球电极的击穿痕迹,在一端球头上开一环形槽,大大提高了开关工作的稳定性。结果说明,电极之间电场的局部增强,有利于提高脉冲气体开关的击穿稳定性。 相似文献
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TE(A)激光器中放电电极的设计与选择 总被引:2,自引:0,他引:2
介绍了TE(A)激光器中Rogowski电极和近似Rogowski电极、Chang电极和紧凑式Chang电极、两类Ernst电极和紧凑式Ernst电极的设计方法。给出了上述放电电极的面型和表面电场分布,简述了制造上述电极的注意事项。在同等电场均匀度和均匀电场分布范围的情况下,对比了保角映射型电极的尺寸大小和电场分布特点。综合放电电极的面型、制造难度、辉光放电实验可知,在要求高能量和高功率的场合下,选择Ernst电极较好;在脉冲激光指标要求一般的场合下,选择近似Rogowski电极较好。 相似文献
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建立综合螺旋桨影响的平流层飞艇气动外形优化设计平台.采用Hicks-Henne型函数法参数化艇身轮廓,发展IDW-TFI混合动网格技术实现变形网格高效生成;基于作用盘理论模拟螺旋桨,建立飞艇流场高效数值求解方法.以LOTTE飞艇作为初始外形,阻力系数最小为目标,飞艇体积作为约束条件,通过NLPQL算法寻优获得最佳艇身设计方案.优化后飞艇的尾部形状较平坦,艇身最大横截面位置前移,气动性能得到明显改善,其阻力系数相对于初始外形降低了26.88%. 相似文献
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高效集成电光调制器和开关的电极与光波导的优化设计 总被引:2,自引:0,他引:2
集成电光调制与开关的效率取决于光波导中电光重叠因子Γ的大小,直接影响此因子的有电极宽度、电极间距、光模场尺寸、以及电极与光波导的相对位置等参量。本文利用集成电光调制器电极电场的分布规律,研究了各种结构中影响电光重叠因子的诸参量之间的关系;根据实际工艺条件,应用系统优化方法尽可能对各种参量进行优化计算,得到了实现高效调制和开关的全部参量的优化设计结果。 相似文献
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The results of two-dimensional micromagnetic modeling of magnetization patterns in Permalloy ellipses under the influence of rotating constant-amplitude magnetic fields are discussed. Ellipses of two different lateral sizes have been studied, 0.5 μm×1.5 μm and 1 μm×3 μm. The amplitude of the rotating magnetic field was varied between simulations with the condition that it must be large enough to saturate or nearly saturate the ellipse with the field applied along the long axis of the ellipse. For the smaller ellipse size it is found that the magnetization pattern forms an S state and the direction of the net magnetization lags behind the direction of the applied field. At a critical angle of the rotating magnetic field the direction of the magnetization switches by a large angle to a new S state. Both the critical angle and the angle interval of the switch depend on field amplitude. For this new state, it is instead the applied field direction that lags behind the magnetization direction. The transient magnetization patterns correspond to multi-domain patterns including two vortices, but this state never exists for the equilibrated magnetization patterns. The behavior of the larger ellipse in rotating field is different. With the field applied along the long-axis of the ellipse, the magnetization of the ellipse is nearly saturated with a vortex close to each apex of the ellipse. As the field is rotated, this magnetization pattern remains and the net-magnetization direction lags behind the direction of the field until for a certain angle of the applied field an equilibrium multi-domain state is created. Comparisons are made with corresponding experimental results obtained by performing in-field magnetic force microscopy on Permalloy ellipses. 相似文献
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介绍了一种1 MV低阻抗加速器的结构及其对主开关系统的要求,并对确定使用的油介质开关进行了优化设计与模拟。优化后的结果显示,开关工作在1 MV时,放电电感约100 nH,分布电容约150 pF,充电电感约360 nH;开关的放电参数不会对波形造成过大的不良影响,充电参数不影响Marx发生器给形成线的充电时间,开关内部电场安全,变压器油与尼龙交界面不会发生闪络。设计后的开关与其它部件搭建起低阻抗加速器进行调试,加速器输出约700 kV,70 kA、脉宽150 ns的电子束,开关满足实验需求。 相似文献
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Electric ignition energy evaluation and the energy distribution structure of energy released in electrostatic discharge process 下载免费PDF全文
Ignition energy is one of the important parameters of flammable materials, and evaluating ignition energy precisely is essential to the safety of process industry and combustion science and technology. By using electric spark discharge test system, a series of electric spark discharge experiments were conducted with the capacitor-stored energy in the range of 10 J, 100 J, and 1000 J, respectively. The evaluation method for energy consumed by electric spark, wire, and switch during capacitor discharge process has been studied respectively. The resistance of wire, switch, and plasma between electrodes has been evaluated by different methods and an optimized evaluation method has been obtained. The electric energy consumed by wire, electric switch, and electric spark-induced plasma between electrodes were obtained and the energy structure of capacitor-released energy was analyzed. The dynamic process and the characteristic parameters(the maximum power, duration of discharge process) of electric spark discharge process have been analyzed. Experimental results showed that, electric spark-consumed energy only accounts for 8%–14% of the capacitor-released energy. With the increase of capacitor-released energy, the duration of discharge process becomes longer, and the energy of plasma accounts for more in the capacitor-released energy. The power of electric spark varies with time as a damped sinusoids function and the period and the maximum value increase with the capacitor-released energy. 相似文献
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百kV/cm高场强纳秒脉冲条件下,采用J. C. Martin经验公式估算SF6气体击穿场强时,估算值与实验结果差异显著。为了进一步指导高场强脉冲气体开关设计,为开关工作状态调节提供依据,借鉴经典击穿场强经验公式形式建立了百kV/cm场强下SF6气体开关纳秒脉冲击穿场强和时延与实验参数之间的关系,基于实验数据拟合形成了修正系数的击穿场强和时延经验公式。研究表明,百kV/cm场强和纳秒脉冲条件下脉冲电压斜率对开关击穿特性有重要影响,击穿场强与击穿时延相互关联。百ns至μs脉冲与几十ns脉冲气体放电机理的区别引起放电过程中击穿时延组成发生变化,导致了经典击穿场强经验公式估算值与实验结果的显著差异。修正系数的击穿经验公式可为电磁脉冲模拟器输出开关提供更为精确的工程设计依据。 相似文献
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为了获得高保真的电容式RF MEMS开关自驱动失效阈值功率模型,必须弄清开关膜片上电场分布的边缘场效应。由于受到边缘场效应的影响,在计算开关自驱动失效阈值功率时,不能使用开关与中心导体的正对面积(A)取代受到射频信号频率的开关膜片面积(ARF)。否则,会出现射频信号功率等效电压(Veq)的计算偏差。因此,使用Veq的计算值与开关膜片上的均方根电压值(VRMS)来表征ARF。从而构建一个优值(ARF/A)来表征开关膜片上电场分布的边缘场效应强度。采用HFSS软件构建开关自驱动失效3D电磁模型,针对同一种开关构型,通过仿真得到不同射频信号功率下和不同开关气隙高度下膜片上边缘电场的分布。并与优值计算结果进行比较,初步验证了使用该优值表征开关膜片上电场分布的边缘场效应强度的合理性。 相似文献