A new monochromator with multiple offset cylindrical lenses

作者：Ogawa Takashi^*; Cho Boklae

来源：Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment , 2015, 772: 5-13.

DOI：10.1016/j.nima.2014.10.075

• Monochromator
• Electron energy filter
• High resolution
• Cylindrical lens
• Simulation

This article presents the optics and performance of a new monochromator (MC) with multiple offset cylindrical lenses (CLs). From ray trace simulations and a regression analysis, a single-offset CL is described in first-order matrix expressions. Based on the matrix, a new optics using multiple CLs is constituted It is capable of energy Filtering internally and forms stigmatic and non-energy dispersive images at the exit, It consists of an offset CL doublet located at a specified distance. It is also equipped with two transfer lenses and two apertures. From simulations, an energy dispersion of 23 mu m/eV and an energy resolution better than 10 meV for 4 keV incident energy are achieved. Compared to previous MCs with multi-pole optics, the proposed MC has the additional advantage of a simplified structure. This MC realizes improvements in spatial resolutions for transmission electron microscopy, scanning transmission electron microscopy, and scanning electron microscopy and in energy resolutions for electron energy loss spectroscopy.

• 出版日期2015-2-1