A new type of multifilamentary Nb,Sn wires prepared by the bronze route but with composite cores is found to exhibit considerably enhanced j , values with respect to conventional Ta alloyed wires in the intermediate field range, i.e. >30% between 10 and 12 T. The enhancement of jcis obtained by artificially introduced continuous ribbon-like Ta inclusions of d 10 nm thickness, i.e. close to the coherence length. These inclusions are distributed at a nanometre scale over the filament cross section. The enhanced pinning in the present wires ('artificial pinning') is a consequence of the new Nb,Sn/Tainterfaces with a total area comparable to that of the already existing grain boundary interface.The present method is an extension of the original powder-metallurgical composite core method recently developed in our laboratory. Considerable progress was achieved in view of industrial fabrication, the powder-metallurgical Nb/Ta cores being now replaced by continuous cores consisting of Ta rods surrounded by Nb tubes and bundled together. At the final stage, the Ta-Ta distance is estimated to be .y20 nm, i.e. close to the calculated flux line distance at 10 T. Measurements ofj, up to 20 T as well as the effects of uniaxial tensile strain onj, are presented. Further enhancement of j , is expected by optimising the Ta content and the separations of the Ta-Ta ribbons. the possibility to enhancej, at intermediate fields without the disadvantage of higher AC losses. This may be of particular interest in view of the conductors in future fusion magnets.

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We report a stress control method for Capacitive Micromachined Ultrasonic Transducers (CMUTs) fabricated with sacrificial release process. By annealing a TiAl plate the stress can be shifted from compressive to tensile and its behavior is visualized over temperature and time. Furthermore, a linear dependency of annealing temperature and stress is shown, allowing uncomplicated stress adjustment. Remaining deflection can be explained by both atmospheric pressure and temperature influence of the final process steps. Mechanical long term stability is proven with stress measurements over several months