【作者】 黄永刚；

【导师】 顾真安；

【作者基本信息】 中国建筑材料科学研究总院 ， 材料学， 2014， 博士

【摘要】 微通道板电性能是电子倍增和导电性能的合称，是微通道板的核心性能。揭示电子倍增与导电机制，创新制备技术，是实现高性能MCP制备的关键。本论文在MCP制备工艺与电性能的关系、不同工艺下微孔表面成分与形貌的变化过程、玻璃表面二次电子发射性能等方面进行了系统的探索研究。研究制备工艺对MCP电性能的影响规律。实验验证长径比(α)、孔径、斜切角和开口面积对电子增益与体电阻的影响趋势，并发现在电子增益最大时最佳工作电压（U）不符合惯用理论关系式，即U≠22α，经验关系式U＝22α+(100～200)，而孔径一定时其体电阻（R）与长径比关系式为R=15.3+3α。微孔阵列成形经历“慢-快-慢”酸溶速率的过程，当酸蚀90min后形成内壁洁净的微孔阵列，再延长30min可获得高的电子增益和较低的噪声。高温氢还原后可显著提高电子增益，降低体电阻。其中，还原温度和方式对MCP电性能的影响最显著，体电阻随还原温度增高出现“高-低-高”变化趋势，而相同还原工艺参数下采取活化强迫式还原可显著降低体电阻至标准工艺的50%。镀膜工艺显著影响电子增益，在保证分辨率的前提下减少输出面电极材料伸入微孔的深度至标准的56%，其电子增益可提高2.7倍。分析比较了微孔内表面“点、线”上主要元素的相对含量和化学结合状态，揭示MCP内壁表面各元素化学结合状态的变化过程，发现高电子增益MCP内壁表面存在近周期性分布的硅氧成分微区。首次利用飞行时间法测定了不同工艺条件下含铅铋的硅酸盐玻璃表面的二次电子发射产额，验证表面二次电子发射与表面成分的关系，为MCP二次电子发射性能研究提供新思路。分析比较不同工艺条件下MCP玻璃表面微观形貌的变化过程，构建了MCP导电微结构模型，利用渗流理论量化了体导电值的突变阈值，利用电子隧道导电理论阐明了固定工艺下MCP体电阻随室温和测试板压变化的影响原因，揭示了MCP的电子导电机制。本文通过对不同工艺下玻璃表面成分和微观形貌研究，构建MCP微孔内壁表面微结构模型，结合渗流理论和隧道导电理论揭示了MCP的导电机制，为高性能MCP的研究提供理论依据，为制备工艺的优化提供支撑。更多还原

【Abstract】 The core property of microchannel plate (MCP) is electrical propertiesincluding electron multiplier and electrical conductivity. Therefore, the key point forpreparation of high performance MCP is to clarify the mechanism of electronicmultiplier and conductivity and upgrade preparation technology. In this paper,systymatically researches have been done in the relationship between prepareparameters and electrical properties, variation of components and morphology withdifferent prepare conditions, and secondary electron emission properties.Firstly, the effect of parameters varied in prepare process on electrical propertiesof MCP was investigated. The influence tendency of aspect ratio (α), pore size, biasangle and detection efficiency on gain and bulk resistivity was experimentally verified.In the maximum gain, the optimum voltage (U) deviated from the common theoreticalequation, i.e. U≠22α, and the empirical equation was U＝22α+(100～200).Therelationship of resisitivity and aspect ratio was R=15.3+3α. The formation ofmicropore array experienced from “fast-slow-fast” etching process. Clean microporearray could be obtained by acid etching MCP for90min. If the acid etching time wasextended for another30min, high gain and low noise were achieved. Obvious increaseof gain and decrease of bulk resistivity were found by treatment of MCP withhydrogen reducing at suitable temperature. Electronic conductivity was largelydependent on reducing temperature and methods. The change tendency of bulkresistivity was “high-low-high” with reducing temperature. If reducing parameterswere kept constant, the bulk resitivity could be reduced to50%of that prepared instandard conditons by forced reducing. Coating depth was an important parametersinfluencing gain. For output surface, if extending depth of electrode into microporewas decreased to56%of standard depth, gain could be improved2.7times.Secondly, relative contents and chemical bonding mode of principle componentswere compared and analyzed by locating a point and a line of inner surface. Thechange of chemical bonding mode of various components with electrical properties was clarified. It was found that inner surface of MCP with high gain existedperiodical silica and oxygen micro area. Secondary electron emissions yield (SEEY)of lead-bismuth silicate glasses surface was measured by Time of Flight method (TOF)for the first time. The relationship between SEEY and surface components wasverified.Finally, microscopic morphologies of MCP glass surface were analyzed, andelectrical conductivity model of MCP was to be built. Percolation theory was used toquantify mutation threshold of electrical conductivity. Electron tunneling theory wasused to clarify physical mechanism on electronic conduction of MCP. In combinationwith the chemical reaction mechanism of conductive substance and surface structuremodel, the electron conductivity mechanism was systematically revealed.In this paper, models to describe ideal inner wall surface structure of MCP arebuilt by investigating composition and morphology of MCP. In combination withmorphological models and percolation theory and electron tunneling theory, electronconduction mechanism of microchannel plate is revealed. The researches provide atheoretical basis for the development of high-performance micro-channel plate.更多还原