Magnetic nanoparticles are forming a promising research field in modern science. Especially in medical imaging and therapy nanoparticles may act as solution in various problems. At our institute we develop imaging systems as well as own contrast agents. A correct characterization of these particles is important for the model based reconstruction technique and for particle synthesis quality control. To characterize those particles the institute of medical engineering developed a magnetic particle spectrometer (MPS). This system is basically a zero dimensional magnetic particle imaging device. It measures the particle time response to a varying magnetic field, but resigns the gradient field that is necessary for the spatial resolution.

The correct characterization demands a high homogeneous field generator to eliminate errors due to different excitation and reception. Furthermore the sensitivity has to be maximized, to make small samples measurable and to measure low concentrations of the material in test. This leads to small coils with high homogeneous field profiles, two conflicting arguments. The institute of medical engineering is working on the optimization of those coil geometries, the optimization of the signal chain, and the development of new applications for magnetic particle spectroscopes like the hybrid reconstruction method.