ASC Science Highlights
Tracking the Potential for Damage in Nb3Sn Superconducting Coils from the Hardness of Surrounding Copper
High field superconductor magnets greater than 10 T made from brittle Nb3Sn superconducting wires need special attention to their assembly, strength and endurance. This new study of damage in Nb3Sn superconducting wire from prototype accelerator coils built at CERN provides a path to designing better superconductor cables for the next generation of higher field accelerator magnets.
Hafnium greatly improves Nb3Sn superconductor for high field magnets
Small additions of elemental Hafnium boosts current-carrying capability in Nb3Sn superconductor.
Heat-treatment of Large Hadron Collider Nb3Sn magnets
To increase the rate of particle collisions in the Large Hadron Collider (LHC) at CERN, new powerful magnets will soon be made from Nb3Sn superconducting wires. Here, researchers report a change to the heat-treatment temperature to optimize Nb3Sn superconducting magnet performance.
High-temperature superconducting tape suitable for magnets at 50 teslas and beyond
Recent measurements of superconducting tapes in the MagLab's 45-tesla hybrid magnet shows that the power function dependence of current on magnetic field remains valid up to 45T in liquid helium, while for magnetic field in the plane of the tape conductor, almost no magnetic field dependence is observed. Thus design of ultra-high-field magnets capable of reaching 50T and higher is feasible using the latest high-critical current density REBCO tape.
Ceramic insulation for high-temperature superconducting wire
MagLab scientists and engineers have developed a special coating on Bi-2212 superconducting wire for electrical insulation in superconducting magnets that will enable the wire to be used in ultra-high field nuclear magnetic resonance magnets.
Tweaked recipe delivers record current-carrying capacity in Bi-2212 wires
MagLab-industry partnership ups the critical current density of this high-temperature superconductor by a third.
High-temperature superconducting coils tested for future NMR magnet
Bi-2223 shows promise for 30-tesla all-superconducting instrument for nuclear magnetic resonance.
Better joints to connect wires of promising superconductor
The new technique for connecting Bi-2212 round wires is an important step in building better, stronger superconducting magnets.
A better superconductor for Large Hadron Collider
Scientists have discovered a way to significantly improve the performance of a decades-old superconductor, promising future applications for particle accelerators and research magnets.
Superconducting insert magnet generates new record field of 40.2 teslas
Using a novel method of winding the magnet coil that dispensed with the traditional insulation, the MagLab reached another world record and laid the foundation for more to come.
Record current density in superconducting CORC® magnet cables at 20 teslas
A new type of superconducting cable was successfully tested at high field at the MagLab, opening the door for the next generation of accelerator magnets operating at 20 teslas (T) and above.
Overpressure furnace for processing Bi-2212 high-field magnets
An overpressure furnace capable of developing high current density in significant-sized coils (up to 15 cm diameter and 50 cm long) has been brought into commission. The furnace is enabling reaction of solenoids made out of Bi-2212 destined for tests of NMR quality magnets at proton frequencies greater than 1 GHz.
Evidence for extrinsic, impurity segregation at grain boundaries in high current-density K- and Co-doped BaFe2As2
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.
Low Temperature High Field Continuous Measurement of YBCO
Scientists have developed a new way to test tape made of the promising high-temperature superconductor YBCO, a key step toward building stronger superconducting magnets.
Magnets with High-Temperature Superconducting Round Wire
MagLab scientists developed a method to process high-temperature superconducting Bi-2122 round wire that significantly boosts its ability to carry large electrical currents and generate high magnetic fields.
Oxypnictide SmFeAs(O,F) Superconductor: A Candidate for High-field Magnet Applications
Researchers find high critical current density in the recently discovered oxypnictide superconductor SmFeAs(O,F), raising hopes for potential electronics applications.
Artificial and Self-assembled Vortex-pinning Centers in Superconducting Ba(Fe1-xCox)2As2 Thin Films
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.
Filament Fracture in ITER Conductor under Cyclic Lorentz Force Loading
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.
High Critical Current Density in Fine-grain (Ba0.6K0.4)Fe2As2
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.