Reduction of Porosity for High Critical Current Density Bi-2212 Superconductor Wire

The Department of Energy is seeking superconducting material for a very high-field magnet to be used in a future particle accelerator. Bi-2212 round wire, a high temperature superconductor, is one of the best candidates for this purpose. However, there are significant amount of pores present in the filament packed with powder. These pores are limiting the critical current carrying capability because they hinder the connectivity of current carrying path. In Phase I of this study, we seek to evaluate an augmentation of the drawing steps with an alternate process that will economically reduce the amount of porosity. Swaging has potential for this augmentation because of the high impact of the process. This result in dynamic compaction, which will increase the density of the powder in the tube due to the multiple shock waves produced. Tooling will be modified for the best fit for Bi-2212 wire and samples are to be made and evaluated. High-field magnets have a large number of practical applications in many areas. These magnets are essential components in NMR and ICR spectrometers that are widely used in new drug discovery and biotechnology. Proton therapy for cancer treatment also relies upon a compact cyclotron equipped with such a magnet. Hadron colliders used in high energy physics, and magnetic fusion devices, used in the search for ever-lasting energy source and in basic material behavior studies, also require high field superconducting magnets. Commercial Applications and other Benefits: Higher current density superconducting wire would not only improve the performances of these devices, but would so reduce their costs