中文摘要：

为了提升碳纳米管（CNT）阴极电离规的综合性能和实用性,本文利用离子光学模拟软件SIMION3D8.0和CAD建模软件构建了CNT阴极电离规的物理模型,且通过模拟计算得到不同电极结构参数对CNT阴极电离规各种性能的影响规律。研究结果表明,不同的阴极基座直径、门极尺寸产生不同的电子运动轨迹;电子运动路径随着外屏与阳极栅网之间距离的增大先增大后减小;电子逃逸率随着门极和阳极顶部间距的减小而逐渐增大;聚焦孔直径对正离子的收集影响显著,且气相离子/电子激励脱附离子收集比率在收集孔直径约为2 mm时达到最大。故选用合适的电极结构参数能有效地提高CNT阴极电离规的总体性能,延伸其真空测量下限。

英文摘要：

The ionization gauge with a carbon nano-tube（CNT）cathode was modeled and simulated with software package SIMION3D8.0and CAD to improve its performance and feasibility.The influence of the cathode structure,including the diameters of its base,gate and focusing hole,as well as the distances of its gate/anode and outer-screen/anode-grid,on the characteristics of the gauge was investigated.The simulated results show that the CNT-cathode geometry has a major impact.For example,the electron trajectories depend strongly on diameters of the base and gate;as the outer-screen/anode-grid separation increases,the electron-path length changes in an increase-decrease mode;the electron escape-ratio increases with a decrease of gate/anode distance;depending significantly on the focusing-hole diameter,the collection-ratio between gaseous ion and electron-desorbed ion maximizes at a hole– diameter of about 2mm.We suggest that optimization of the CNT-cathode structure may improve the overall performance of the ionization gauge,especially reducing its lower pressure limit.