Probe Corrector Tuning Guide

Update 2026-10-11: version 2.1 of the manual contains an updated description of the rough STEM alignments that makes more clear how to avoid introducing competing beam tilts in the condenser system.

Recently I’ve been learning a lot more about the optics of the hexapole probe corrector, and I hope to soon have a few more posts up about interesting things I’ve found out. The first post, though, is a very practical one: a guide to tuning the CEOS probe corrector on a TFS Spectra. Older guides were written for the earlier generation of corrector software, and the new versions have a greatly streamlined alignment experience. My procedure is fast: on a good day, on a well trained system, you can go from zero to atoms in 20 minutes.

I’ve made the manual as a PDF, which you can download here. The document is typeset in typst using the Tufte memo template, which I found to be appropriate for the discursive style of this manual.

I also recorded myself going through the procedure, with some additional commentary on useful features in the CEOS software, and you can watch it here: