Scanning photoelectron microscope (SPEM)

The heart of the measurement station is the SPEM. The main components are (i) a zone plate optic system, which provides the microprobe; (ii) a specimen positioning and scanning system, and (iii) a hemispherical electron analyzer with multichannel plate. The SPEM vacuum chamber is mounted through a special support on to a pneumatic antivibrational table with a pneumatic system. The chamber support and the pneumatic system of the table allows movements of the microscope chamber in the horizontal and vertical directions that are necessary for alignment of the central axis of the chamber and the zone plate optic system with the beam. The finite alignments of zone plate optics are performed through two independent XYZ-stepper motor stages for zone plate and order selecting aperture. The alignment is verified by the beam diagnostics mounted inside including Multichannel plate detector and photodiode for X-Ray transmission measurements. The sample holder manipulator has XYZ stepper motor coarse stage and XY precision piezo motor fine stage, and a liquid nitrogen cooling stage. Hemispherical electron analyser is mounted on 6 degrees of freedom manipulator.

More detailed description of each conceptual part of the microscope can be found in the following:
zone plate optic system
specimen positioning and scanning system
hemispherical electron analyzer with multichannel plate

Last Updated on Friday, 20 January 2012 15:43