Applications for superconducting wires, which carry electricity without resistance when cooled to a critical temperature, include underground transmission cables, transformers and large-scale motors and generators. But these applications require wires to operate under different temperature and magnetic field regimes.
This figure shows the critical current, Ic, and engineering critical current density, JE, in a superconducting wire as a function of applied magnetic field orientation at 65 Kelvin and 3 Tesla. The top curve shows results from a newly published ORNL study. The other two curves are from previously reported record values. A minimum JE of 43.7 kiloamperes/cm2 (assuming a 50 micron thick stabilizer layer) and a minimum Ic of 455 Amperes/cm was obtained for all applied field orientations. This is the highest reported performance for a superconductor wire or a film on a technical substrate.
A team led by ORNL’s Amit Goyal demonstrated that superconducting wires can be tuned to match different operating conditions by introducing small amounts of non-superconducting material that influences how the overall material behaves. Manipulating these nanoscale columns -- also known as defects -- allows researchers to exert control over the forces that regulate the wires’ superconducting performance. The team’s findings are published in Nature Publishing Group’s Scientific Reports.
“Not only can we introduce these nanocolumn defects within the superconductor and get enhanced performance, but we can optimize the performance for different application regimes by modifying the defect spacing and density,” Goyal said.
A wire sample grown with this process exhibited unprecedented performance in terms of engineering critical current density, which measures the amount of current the wire can carry per unit cross-sectional area. This metric more accurately reflects the real-world capabilities of the material because it takes into account the wire’s non-superconducting components such as the substrate and the buffer and stabilizer layers, Goyal said.
“We report a record performance at 65 Kelvin and 3 Tesla, where most rotating machinery applications like motors and generators are slated to operate,” he said.
The paper reports a minimum engineering critical current density at all applied magnetic field orientations of 43.7 kiloamperes/cm2, which is more than twice the performance level needed for most applications. This metric assumes the presence of a 50-micron-thick copper stabilizer layer required in applications.
Generating defects in the superconductor is accomplished through an ORNL-developed self-assembly process, which enables researchers to design a material that automatically develops the desired nanoscale microstructure during growth.
The mechanism behind this process, which adds very little to the production cost, was the subject of a recently published study by a team led by Goyal in Advanced Functional Materials.
“When you’re making the wires, you can dial-in the properties because the defects self-assemble,” Goyal said. “You change the composition of the superconductor when you’re depositing the tape.”
Goyal, who has collaborated with multiple superconducting technology companies, hopes the private sector will incorporate the team’s findings to improve upon existing products and generate new applications.
The study is published as “Engineering nanocolumnar defect configurations for optimized vortex pinning in high temperature superconducting nanocomposite wires.” Co-authors are ORNL’s Sung Hun Wee and Claudia Cantoni and the University of Tennessee’s Yuri Zuev.
The research was sponsored by DOE’s Office of Electricity Delivery and Energy Reliability. The research was supported by ORNL's Shared Research Equipment (ShaRE) User Program, which is sponsored by DOE’s Office of Science.
ORNL is managed by UT-Battelle for the Department of Energy's Office of Science. DOE's Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit http://science.energy.gov.
Morgan McCorkle | EurekAlert!
Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously
17.01.2017 | Sonderforschungsbereich 668
Manchester scientists tie the tightest knot ever achieved
13.01.2017 | University of Manchester
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction