The magnetic transmission x-ray microscopy project at BESSY II

The first transmission x-ray microscope, dedicated for magnetic imaging is currently being built at the beamline ID-10 at BESSY II in Berlin using a helical undulator which provides photons with circular-, horizontal-, vertical, and linear polarization under various angles in the energy range between 0.2 and 2 keV. The microscope will use the x-ray circular and the x-ray linear magnetic dichroism as a magnetic contrast to study ferromagnetic and antiferromagnetic domains. A condenser with dynamical aperture synthesis will produce a reduced, spatially fixed, incoherent, and vertically dispersed image of the source, which will be matched to the aperture of the micro zone plate (MZP). In an object field of 15 μm by 15 μm a monochromaticity of E/ΔE = 1700 will be obtained, which is sufficient for magnetic spectromicroscopy, enabling us to investigate lateral distributions of magnetic moments separated by different elements, chemical shifts and even by spin and orbital contributions. A solenoid and/or lithographically patterned microcoils will allow studying magnetization reversal processes on different time scales, down to a sub-nanoseconds level where precessional switching and damping mechanisms occur.