SBIR Phase I: Optimization of a Sintering and Manufacturing Process for Prototype MgB2 Wires for Next-Generation Cryogenic-Free 1.5T and 3.0T MRI

This Small Business Innovation Research (SBIR) Phase I project will develop prototype MgB2 wires for next generation cryogen-free 1.5 Tesla (T) and 3.0 T magnetic resonance imaging (MRI) systems, by adding both magnetic and nonmagnetic impurities. These impurities will amplify the vortex pinning due to magnetic impurities, while compensating the concomitant magnetic impurity-induced transition temperature reduction with nonmagnetic impurities. This new technique will lead to a significant enhancement of high field properties of type II superconductors (i.e. increased critical current densities and upper critical fields). This conversion of ordinary superconductors into magnetic superconductors will open a new frontier for superconducting magnet technology. This SBIR project employs optimization of a sintering and manufacturing process for prototype MgB2 wires to guarantee the homogeneous dispersion of impurities along the wire and to achieve the maximal critical current density in a cost efficient way. This project will determine the optimum sintering conditions (i.e., temperature, pressure, and time), utilizing liquid phase sintering of impurities, and will test both in-situ and ex-situ powder-in-tube (PIT) manufacturing processes for producing the highest critical current densities in MgB2 wires. The broader impact/commercial potential of this project includes the possibility of fabricating next-generation cryogen-free 1.5T and 3.0T MRIs, using the resulting MgB2 wires. The low-cost next-generation MRIs will replace the current Nb-Ti-magnet based MRIs, enhancing the public health significantly, because these envisioned MRIs will operate at a higher temperature, 20 K, obviating the need for expensive liquid helium. The elimination of liquid helium cryogen will lead to simple and versatile designs and almost maintenance-free operation, reducing the MRI scan cost up to 40%. The resulting prototype MgB2 wires will be also crucial for next generation of cryogen-free magnets for nuclear magnetic resonance (NMR), particle accelerators, and fusion reactors. Additionally, it is straightforward to apply this technique to Nb-Ti and Nb3Sn magnet materials. Accordingly, this novel technique has the potential to revolutionize superconducting magnet technology and opens a new research field of converting ordinary superconductors into magnetic superconductors. MgB2 wires are a viable candidate for follow-on applications in electric power transmission, superconducting fault current limiters, generators, and motors, all of which could be enabled by this innovative technique.