The influence of emitter conditioning on the performance of a tungsten <111> cold field emission gun operating at 300 kV

Electron Microscopy and Analysis Group Conference 2013

Ross, I.M.^1 ; Li, W.^1 ; Walther, T.^1

Kroto Centre for High Resolution Imaging and Analysis, Department of Electronic and Electrical Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, United Kingdom^1

关键词: Aberration-corrected;    Beam characteristics;    Beam currents;    Cold field emissions;    Emitter tips;    Energy resolutions;    Low beam;    Tip radius;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/522/1/012053/pdf
DOI  :  10.1088/1742-6596/522/1/012053

来源: IOP

【 摘 要 】

In this contribution, we examine the influence of emitter conditioning for atungsten cold field emission gun on the emission and beam characteristics of a double aberration corrected electron microscope. By varying the post flash build-up parameters we can control the effective emitter tip radius. A sharp emitter yields an energy resolution of 0.31eV but relatively low beam current whereas an increased tip radius results in a reduction in energy resolution to 0.4eV but much higher potential beam current. Consequently, careful control of the build-up parameters can be used as a means of tailoring the emission to suit specific instrumental requirements.