基于碳纳米管阴极电离规中电子/离子微观运动特征与性能优化研究

Extremely high vacuum measurement is a frontier and challenging academic problem in vacuum metrology, however, ionization gauge based carbon nanotube cathode is thought that is very hopefully able to solve the problem of extreme high vacuum measurement. Unfortunately, because of low field emitting current and high applied gate and anode voltage in operation, which restrict its sensitivity and vacuum measurement lower limit. This project is intended to electron/ion microcosmic movement characteristics based spherical oscillator gauge with carbon nanotube cathode as study object, analysis and calculation of matching CNT cathode and the spherical oscillator. Studying the influences of structure sizes and electrodes potential on the microcosmic parameters (including electron effective trajectory, electron transmission and escape, and ratio of electron simulated desorption ions to gas ions and so on). In order to revise the calculation results, experiment study is performed. Based on the theory and experiment, we will investigate the effect microcosmic parameters on the sensitivity and vacuum measurement limit and optimize the structure sizes and electrodes potential, and further establish the relation of microcosmic parameters – simulation optimization – whole performance. In view of the characteristics of ionization gauges, the new-style extreme high vacuum ionization gauge model with carbon nanotube cathode is built. The built analysis method of the project can be extended to the theory analysis and development of new-styles of extreme high vacuum ionization gauge, which could play an enormous promotion action for resolving the problem of extreme high vacuum measurement and key technology, possessing important scientific significance and engineering practicality value.

极高真空测量是真空计量学领域一项前沿而富有挑战的学术难题，碳纳米管（CNT）阴极电离规被认为是未来很有希望解决极高真空测量难题的真空规。然而，目前CNT阴极电离规工作时存在场发射电流小、阳极电压高等问题，成为制约其灵敏度和测量下限等性能的主要原因。本项目拟以CNT阴极球形振荡器规电子/离子微观运动特征为研究对象，计算分析CNT阴极与球形振荡器的匹配性，研究电极结构、电极电压和电极布局变化对电子有效运动轨迹、电子能量、电子透过率和逃逸率，以及电子激励脱附离子/气相离子收集比率等微观参量的影响规律；通过实验验证并修正理论模型，进而优化电离规性能，建立微观参量—模拟优化—整体性能之间的关系，构建满足极高真空测量要求的新型CNT阴极电离规结构模型。本项目旨在揭示CNT阴极电离规电子/离子微观运动特征对其性能的影响规律，为有效解决极高真空测量难题和研制出CNT阴极极高真空电离规奠定理论和技术基础。

目前，碳纳米管（CNT）阴极电离规普遍存在灵敏度低、测量下限不能满足极高真空测量要求等问题，成为制约其灵敏度和测量下限等性能的主要原因。本项目综合考虑制约CNT阴极电离规的技术瓶颈，创新性地提出了“微观参量——模拟优化——整体性能”的研究思路，并取得了如下重要突破：（1）以CNT阴极电离规电子/离子微观运动特征为研究对象，采用离子光学模拟软件，构建了不同类型的碳纳米管阴极电离规物理模型，系统研究了电极参数对电离规中电场分布和离子运动轨迹的影响，并最终确定了CNT阴极电离规的最佳工作参数；（2）通过理论模拟和实验验证相结合的方法，揭示了CNT阴极电离规中电极结构、电极电压和电极布局、以及与CNT阴极的工作匹配性等多因素和电离规微观参量之间的定量关系，为CNT阴极电离规的制备提供了一种科学而实用的计算方法；（3）在上述理论研究结果的指导下，开展了CNT阴极电离规计量学性能研究，最终使CNT阴极电离规实现了测量下限达10-9Pa量级的极高真空测量，灵敏度为0.03Pa-1。.在本项目研究过程中，发表学术论文6篇，申请国家专利2项，获中国计量测试学会科技进步一等奖1项。另外，本项目提出的研究方法可推广应用于各种新型电离规的研发和理论分析中，为解决极高真空测量难题提供了有效的研究途径。