金属微结构阵列表面的二次电子能谱特性研究

Suppression of secondary electron yield of metal surfaces is known to be efficient in improving performance of devices/systems such as microwave devices, vacuum electronic devices and accelerators. In recent years, microstructure array surfaces have been widely used in secondary electron yield suppression. However, the secondary electron spectrum characteristic of microstructure array surface is still unclear and thus it becomes a bottleneck in evaluating performance improvement by using microstructure array surface in real devices/systems. So, in this project, we will study the secondary electron spectrum of microstructure array surface, its phenomenological model and we will also clarify how it influences multipactor behavior of microwave devices. First, based on the accurate phenomenological model of secondary electron emission of metal plate, we will establish the calculation method of secondary electron spectrum of microstructure array surface using Monte Carlo simulation. Second, we will study the relation between secondary electron spectrum and its influence factors such as microstructure’s shape and size, incident energy and angle of primary electrons. And then, we will derive a phenomenological model describing secondary electron spectrum characteristic of microstructure array surface and study the secondary electron spectrum characteristic dependence of multipactor region of parallel plate waveguide. Last, we will fabricate microstructure array surface samples by process such as photolithography and measure their secondary electron emission properties as a validation of the established calculation method and phenomenological model. This project will have scientific and applied significance in improving reliability of devices/systems such as microwave devices using microstructure array surface.

金属表面二次电子产额的抑制在提高空间微波器件、真空电子器件、粒子加速器等器件/系统性能方面具有重要应用，利用微结构阵列表面实现二次电子产额抑制的研究近年来取得了显著进展。然而，对微结构阵列表面二次电子能谱特性却缺乏了解，构成了准确评估其实际应用效果的瓶颈。为此，本项目将系统研究微结构阵列表面的二次电子能谱特性，建立其唯象模型并评估其对微放电特性的影响。基于准确的平滑表面二次电子发射唯象模型，结合蒙特卡罗模拟建立微结构阵列表面的二次电子能谱特性计算方法；系统研究微结构形状尺寸、初始电子入射参数等因素对二次电子能谱特性的影响，建立微结构阵列表面二次电子能谱唯象模型，评估二次电子能谱对平行板波导微放电特性的影响；通过光刻等工艺制备金属微结构阵列表面并测试其二次电子能谱特性，优化理论计算方法及其二次电子能谱唯象模型。研究成果对于应用微结构阵列表面提高微波器件等的可靠性具有重要科学意义和实用价值。

材料的二次电子发射是许多学科和技术领域的基础问题，本项目针对微结构表面的二次电子发射特性及其应用展开研究。主要开展的研究内容及取得的成果如下：1.结合二次电子能谱分布分析了偏压法测试二次电子发射系数的原理及误差，为提高测量精度提供了理论支撑；2.从二次电子能谱角度分析了圆孔结构抑制二次电子发射的机制，进而提出并仿真验证了采用微纳复合结构进行二次电子发射抑制的新方法；3.提出了采用网孔波导结构实现微波部件微放电阈值的新方法并进行了仿真验证，阈值可提高至少8dB左右；4.系统深入地研究了高斯型随机粗糙表面的二次电子发射特性；5.开展了激光刻蚀、低气压蒸发等工艺在二次电子发射系数抑制中的应用研究，获得了接近于1的二次电子发射系数；6.开展了多种结构的二次电子发射能谱研究。本项目研究成果对于揭示二次电子发射抑制机理以及其在相关领域的应用具有借鉴参考意义。