The correction of spherical (Cs) and chromatic (Cc) aberrations cannot be carried out with rotationally symmetric electron lenses (Scherzer, Z. Phys. 101 (1936) 593 ). Therefore, multipole elements have to be used for the correction.

  • Our Cc/Cs-Corrector uses electric/magnetic quadrupoles and octupoles for correction as invented by Rose (Optik 33 (1971) 1).
  • The Cs-Correctors use hexapoles in an arrangement with additional round lenses (Rose, Optik 85 (1990) 19).
  • We have developed a purely electrostatic Cc/Cs-Corrector (Weißbäcker & Rose, 2001) suitable for ion optical applications.

The principal questions about electron microscopy are answered here: