Chromatic and Spherical Aberration Correction with Hexapole and Quadrupole Fields
Abstract
We report the development of a chromatic and spherical aberration corrector based on combinations of hexapole and quadrupole fields. Thick hexapole fields are used to generate negative third order spherical aberration and to correct residual axial and off-axial aberrations. As an alternative to the use of round transfer lenses placed between the hexapoles, a quadrupole multiplet producing superimposed electric and magnetic quadrupole fields is used to produce negative chromatic aberration. This quadrupole multiplet also functions as a transfer doublet within the corrector. The simultaneous correction of chromatic and spherical aberrations using this corrector design is described, and a resolution improvement is demonstrated for cases where the energy spread is limiting.
Keywords
Cite
@article{arxiv.2509.11458,
title = {Chromatic and Spherical Aberration Correction with Hexapole and Quadrupole Fields},
author = {Shigeyuki Morishita and Hidetaka Sawada and Norihiro Okoshi and Shunsaku Waki and Hironori Tanaka and Katsunori Ichikawa and Angus Kirkland},
journal= {arXiv preprint arXiv:2509.11458},
year = {2026}
}