Abstract: A multi-beam generation unit for a multi-beam system has larger individual focusing power for each of a plurality of primary charged particle beamlets. The multi-beam generation unit comprises an active terminating multi-aperture plate. The terminating multi-aperture plate can be used for a larger focusing range for an individual stigmatic focus spot adjustment of each beamlet of a plurality of primary charged particle beamlets.

Abstract: To prepare a sample for atom probe tomography, a raw sample body having a surface and a region of interest (ROI) to be inspected by APT is provided. Pillars containing the ROI are formed into the surface of the raw sample body via ablation of material of the raw sample body from the surface with an ultra-short pulsed laser. Redeposited ablated material is removed in the region of the formed pillars. The surface of the formed pillars is polished. A preparation device to perform such a preparation method includes a sample handling unit, a pillar forming unit including an ultra-short pulsed laser, a removal unit to remove redeposited ablated material, and a polishing unit. The result is an efficient preparation of robust samples for atom probe tomography. To investigate a region of interest of a sample, the preparation method is performed and then atom probe tomography of the region of interest is performed.