光学精密工程2025，Vol.33Issue(11)：1700-1712,13.DOI:10.37188/OPE.20253311.1700
磁浸没热场发射电子枪
Thermal field electron gun immersed in magnetic lens field
摘要
Abstract
To enhance the probe beam current of scanning electron microscopes and related devices,a thermal field electron gun immersed in a magnetic lens field was designed to collect electrons emitted from the cathode and increase the effective emitted beam current.The optical properties of the magnetic field-immersed thermal field electron gun were theoretically analyzed,and the performance of three magnetic lens configurations—single polepiece,double polepiece with axial gap,and double polepiece with radial gap—was simulated and compared.A magnetic field-immersed electron gun was subsequently developed based on the double polepiece with axial gap lens,and the variations in beam spot size,beam current,and angular current density in response to the magnetic immersion lens were examined.Experimental measure-ments of the magnetic field distribution of the immersion lens and the effective emitted beam current of the magnetic field-immersed electron gun were conducted using a dedicated platform.Results demonstrate that the measured magnetic field distribution closely matches simulation predictions.The effective emitted beam current reached 44.97 nA at a low acceleration voltage of 3.3 kV and 638.12 nA at a high accelera-tion voltage of 23.5 kV,representing an approximate fourfold increase compared with conventional ther-mal field electron guns.关键词
电子光学/热场发射电子枪/磁浸没透镜/双极靴透镜Key words
electron optics/thermal field electron gun/magnetic immersion lens/double polepiece lens分类
信息技术与安全科学引用本文复制引用
赵伟霞,张利新,刘俊标,殷伯华,韩立..磁浸没热场发射电子枪[J].光学精密工程,2025,33(11):1700-1712,13.基金项目
国家重点研发计划资助项目(No.2022YFF0709400) （No.2022YFF0709400）
中国科学院科研仪器设备研制项目(No.PTYQ2024BJ0004) （No.PTYQ2024BJ0004）
