Scientists have discovered a way to significantly improve the performance of a decades-old superconductor, promising future applications for particle accelerators and research magnets.
Here we study the microstructural and transport properties of Co-Ba122 thin films in which secondary non-superconducting phases have been introduced during film growth in two different ways: first by using a Co-Ba122 target with a small amount of oxygen, second by alternating two different targets: a clean CoBa122 and an undoped Ba122 target.
Hired in 2015 as chief scientist, this eminent physicist brings a dynamic array of talents to the MagLab.
The new technique for connecting Bi-2212 round wires is an important step in building better, stronger superconducting magnets.
Reduced-size prototype coils for the 32 T all-superconducting magnet have been successfully tested. The results include the generation of 27 T, which is a record for superconducting magnets.
Grain boundaries in BaFe2As2 (122), which is an iron-based superconductor, block current flow. This study, which was a collaboration with a group at Northwestern University, used a Local Electrode Atom Probe (LEAP), which is a relatively new experimental tool, to make a 3-D atom-by-atom reconstruction of a region of a 122 sample that included a grain boundary. The data showed that the chemical composition varied across the grain boundary and in that oxygen was present at the grain boundaries. These variations in composition may contribute to grain boundary's reduced current carrying capacity.
First direct evidence that filament fracture accompanies degradation of superconducting cables designed for the International Thermonuclear Experimental Reactor (ITER). The tokomak fusion reactor, now under construction in France, is an international collaboration crucial to future energy generation from nuclear fusion.
Ferro-pnictide superconductors attracted immediate attention for potential applications due to their high superconducting transition temperatures (Tc up to 56 K) and high upper critical magnetic fields (Hc2 over 100 T). Unfortunately, much as in cuprates, grain boundaries (GBs) were found to obstruct their current carrying capability. This posed a serious technological problem because wires for magnets cannot be single crystals and, thus, inevitably contain grain boundaries. This work shows that low-temperature synthesis of the compound (Ba0.6K0.4)Fe2As2 (Ba-122) in the form of polycrystalline wire achieves a current density three times that of state-of-the-art Nb3Sn wires.
At the National MagLab and other labs across the globe, the race to discover ever-warmer superconductors is heating up. Find out what these materials are, what they’re good for and why this field is red hot.
MagLab engineers are building two cable-in-conduit superconducting coils for hybrid magnets, each with a resistive inner coil and a superconducting outer coil.