Thomas J. Watson Research Center, IBM Research Division, 1101 Kitchawan Road, P.O. Box 218, Yorktown Heights, NY 10598, USA.
Ultramicroscopy. 2012 Aug;119:33-9. doi: 10.1016/j.ultramic.2011.09.011. Epub 2011 Sep 22.
In this paper we discuss a topic that was close to Prof. Gertrude Rempfer s interests for many years. On this occasion of her 100th birthday, we remember and honor Gertrude for her many outstanding contributions, and for the inspiring example that she set. We derive theoretical expressions for the aberration coefficients of the uniform electrostatic field up to 5th order and compare these with raytracing calculations for the cathode lens used in Low Energy Electron Microscopy and Photo Electron Emission Microscopy experiments. These higher order aberration coefficients are of interest for aberration corrected experiments in which chromatic (C(c)) and spherical (C₃) aberrations of the microscope are set to zero. The theoretical predictions are in good agreement with the results of raytracing. Calculations of image resolution using the Contrast Transfer Function method show that sub-nanometer resolution is achievable in an aberration corrected LEEM system.
在本文中，我们讨论了一个多年来一直是格特鲁德·伦珀教授（Prof. Gertrude Rempfer）关注的话题。值此她 100 岁生日之际，我们缅怀并尊敬格特鲁德，感谢她的众多杰出贡献，以及她树立的激励榜样。我们推导出了最高到 5 阶的均匀静电场像差系数的理论表达式，并将这些表达式与用于低能电子显微镜和光电发射显微镜实验的阴极透镜的光线追踪计算进行了比较。这些更高阶的像差系数对于在显微镜的色差（C(c)）和球差（C₃）被设置为零的像差校正实验中很有意义。理论预测与光线追踪的结果吻合良好。使用对比度传递函数方法计算的图像分辨率表明，在像差校正的 LEEM 系统中可以实现亚纳米分辨率。
