Cambridge team make superconductor ‘golf ball’
Research led by University of Cambridge engineers claim to have made a breakthrough in superconductor science by harnessing the equivalent of three tonnes of force inside a golf ball-sized sample of material that is normally as brittle as fine china.
The research team said what is significant about this discovery is that it demonstrates the potential of high-temperature superconductors for applications in a range of fields, including flywheels for energy storage, ‘magnetic separators’, which can be used in mineral refinement and pollution control, and in high-speed levitating monorail trains.
The research team managed to ‘trap’ a magnetic field with a strength of 17.6 Tesla in a high temperature gadolinium barium copper oxide (GdBCO) superconductor, beating the previous record by 0.4 Tesla.
According to Professor David Cardwell of Cambridge’s Department of Engineering, who led the research, in collaboration with Boeing and the National High Field Magnet Laboratory at the Florida State University: “There are real potential gains to be had with even small increases in field.”
“This work could herald the arrival of superconductors in real-world applications,” said Professor Cardwell. “In order to see bulk superconductors applied for everyday use, we need large grains of superconducting material with the required properties that can be manufactured by relatively standard processes.”
A number of niche applications are currently being developed by the Cambridge team and its collaborators, and it is anticipated that widespread commercial applications for superconductors could be seen within the next five years.
Superconductors can carry currents that are typically 100 times greater than copper, which gives them considerable performance advantages over conventional conductors and permanent magnets.
Superconductors are materials that carry electrical current with little or no resistance when cooled below a certain temperature.
While conventional superconductors need to be cooled close to absolute zero (zero degrees on the Kelvin scale, or –273 °C) before they superconduct, high temperature superconductors do so above the boiling point of liquid nitrogen (–196 °C), which makes them relatively easy to cool and cheaper to operate.
Superconductors are currently used in scientific and medical applications, such as MRI scanners, and in the future could be used to protect the national grid and increase energy efficiency, due to the amount of electrical current they can carry without losing energy.
The new record was achieved using 25 mm diameter samples of GdBCO high temperature superconductor fabricated in the form of a large, single grain using an established melt processing method and reinforced using a relatively simple technique.
The previous record of 17.2 Tesla, set in 2003 by a team led by Professor Masato Murakami from the Shibaura Institute of Technology in Japan, used a highly specialised type of superconductor of a similar, but subtly different, composition and structure.
The research was funded by The Boeing Company and by the UK Engineering and Physical Sciences Research Council (EPSRC). The National High Magnetic Field Laboratory, where the measurements were performed, is funded the National Science Foundation and the State of Florida.Tags: University of Cambridge