On The Use of Highly Densified Bi-2212 Wire for Superconducting Magnet Application

The Department of Energy is seeking ancillary technologies to enhance the performance of high filed superconducting materials critical for the very high-field magnets 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. This composite consists of many small filaments filled with fine powder in silver matrix. A recent study showed that the electrical performance of this composite is better if the filament cores are densely packed. However, the highly dense filaments can be easily damaged in the cabling step, in which many strands are consolidated for magnet use. In this study, we seek to evaluate processes for producing cable, particularly Rutherford Cable, with minimal damaged filaments and how to best use this cable for high field superconducting magnets. The key is to identify at what stage of cabling and/or magnet fabrication we need to densify the filaments. High-field magnets have a large number of practical applications in many areas. These magnets are essential components in the 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. Higher current density superconducting wire would not only improve the performances of these devices, but would also reduce their costs.