A systematic study of the influence of the milling energy of the precursor powder on the microstructure and the superconducting properties of MgB 2 bulk samples and wires, and, in addition, the deformation behavior of the wires is presented. An explicit approximate formula for the energy transferred to the powder sample during milling and its dependence on the parameters of the milling process is developed and used for the data analysis. For higher milling energies the amount of the reacted MgB 2 -phase shows a strong increase. The transport critical current density of wires can be enhanced by using precursor powder milled with higher energy. Because the deformation properties are degraded to some extent, one has to find a compromise of the preparation parameters between current density and deformation behavior.

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In the past (Bi Pb) 2 Sr 2 Ca 2 Cu 3 O Ag/Ag-alloysheathed High-Temperature Superconductor (HTS) tapes (Bi-2223 tapes) have been proven being suitable for building quite different system components for a variety of applications.Nevertheless it revealed that applications like Power Transmission Lines, Transformers, Motors/ Generators, SMES, very high field magnets and MRI put very special requirements on the tapes which differ from application to application.The most important point is that the tapes will provide cost-efficient performance for the special application. This means that it's not sufficient to analyze the price in $/kAm, but additionally it's necessary to consider e.g., AC-losses, geometry, mechanical strength and insulation properties and how they contribute to cost. We discuss a subset of the different requirements from the view of a tape supplier.We depict the current status of the tape production (unit lengths 1000 m, overall current densities 100 A mm 2 , steep E-I-characteristics ( -value 30 at standard conditions and even at low temperatures and/ or high magnetic fields), low AC-losses combined with remarkable critical currents of 50 A mm 2 , reliable properties of mechanics and insulation.