Plasma synthesized doped boron nanopowder for magnesium diboride superconductors

DESCRIPTION (provided by applicant): The availability of magnetic resonance imaging (MRI) scanners is having a significant impact on public health, and greater availability of these units in the US and throughout the world is desired. A primary factor limiting availability is the existing superconductor magnet technology. Presently, commercial MRI magnets require liquid helium (LHe); however, the world's helium supply is decreasing and the price is increasing. As a result, MRI producers are pushing to develop MRI systems based on LHe-free magnesium diboride (MgB2) superconducting magnets. The goal of this project is to develop doped boron nanopowder made by a plasma synthesis process to be used for producing MgB2. Phase I of this project was highly successful. The plasma synthesis process was scaled from a 10 gram laboratory method to a greater than 200 gram process that can produce the kilometer length wires needed for preliminary evaluation of MRI magnets. Wires made from carbon-doped boron nanopowder hadcritical current densities, Jc, of greater than 105 A/cm2 out to 8 tesla. These are the world's highest performing MgB2 superconductor wires reported to date. This significant improvement exceeded the goals of the program and makes 1.5 and 3 Tesla MRIs based on MgB2 magnets viable in the near-term (3-5 years). The Phase II specific aims are 1) produce multiple kilogram quantities of doped boron nanopowder and use it to fabricate longer lengths of MgB2 wires; 2) scale up the plasma synthesis process for boron nanopowder by increasing the long-term stability and capacity of the plasma synthesis system; and 3) further develop and scale up a vapor-solid synthesis process to make MgB2 nano-sized powder. Specialty Materials, Inc. will complete the work necessaryto develop the plasma synthesis process to produce kilogram-sized batches of boron nanopowder that can be used to fabricate multi-kilometer wires needed for commercial MRI magnets. MgB2 nanopowder development will provide risk mitigation by providing raw material for both in situ and ex situ fabrication of MgB2 wires. This project will be carried out in close collaboration with wire fabricators and MRI end users so that the next generation of MRI scanners based on MgB2 superconducting magnets can be commercialized in a 3-5 year timeframe. PUBLIC HEALTH RELEVANCE: This project will develop boron nanopowder, the most critical raw material for the next generation of magnetic resonance imaging (MRI) scanners based on magnesium diboride (MgB2) magnets. These new MRI scanners will be much less costly, more efficient, more portable, capable of diagnosing medical problems earlier and faster, and will be much more widely available throughout the country and world.