【摘要】 以场发射基本原理为基础,建立四种四极管模型,采用有限差分法对微孔径场发射阵列进行了模拟。在建立模型时,采用的是相同的结构参数,如栅极到阳极间的距离,发射体尖锥的材料和形状,绝缘层的厚度以及各个结构体的电压。各个模型不同的地方在于聚焦级的位置和厚度不同。通过调整聚焦级的位置找到各种结构的最佳发射性能位置,然后通过比较在不同栅极电压的情况下,比较四种结构发射的特性如聚焦性和电流大小,得到一般性结论,并讨论分析了导致电子束光斑大小变化的原因,得出与实际相符合的数值模拟和优化结构,为试验提供设计依据。更多还原

【Abstract】 Based on field emission theory,four kinds of model of quadrode were built up.The process of field emission array is stimulated through the simple construction by using finite difference.In the four configurations the parameters were set in the same way such as,distance between the anode and the grid,the material and shape of the emission array the thickness of insulator and the voltage of every part.But the difference is the location of the focus level and its thickness.Through changing the place of focusing level the best parameter of emission array structure can be found.Then,compared with the focusing capability and the emission electricity that was in the different voltage,the common conclusion was formed.In addition the reason of the variety of electron beam was analyzed.The results of this simulation offers some advantage for design of the experiment.更多还原