Superconductivity is a set of physical properties observed in superconductors:materials where electrical resistance vanishes and magnetic fields are expelled from the material. Unlike an ordinary metallic conductor,whose resistance decreases gradually as its temperature is lowered,even down to near absolute zero,a superconductor has a characteristic critical temperature below which the resistance drops abruptly to zero. An electric current through a loop of superconducting wire can persist indefinitely with no power source.
Technological applications of superconductivity include:
The Meissner effect is the expulsion of a magnetic field from a superconductor during its transition to the superconducting state when it is cooled below the critical temperature. This expulsion will repel a nearby magnet.
High-temperature superconductivity is superconductivity in materials with a critical temperature above 77 K,the boiling point of liquid nitrogen. They are only "high-temperature" relative to previously known superconductors,which function at colder temperatures,close to absolute zero. The "high temperatures" are still far below ambient,and therefore require cooling. The first breakthrough of high-temperature superconductor was discovered in 1986 by IBM researchers Georg Bednorz and K. Alex Müller. Although the critical temperature is around 35.1 K,this new type of superconductor was readily modified by Ching-Wu Chu to make the first high-temperature superconductor with critical temperature 93 K. Bednorz and Müller were awarded the Nobel Prize in Physics in 1987 "for their important break-through in the discovery of superconductivity in ceramic materials". Most high-Tc materials are type-II superconductors.
A superconducting magnet is an electromagnet made from coils of superconducting wire. They must be cooled to cryogenic temperatures during operation. In its superconducting state the wire has no electrical resistance and therefore can conduct much larger electric currents than ordinary wire,creating intense magnetic fields. Superconducting magnets can produce stronger magnetic fields than all but the strongest non-superconducting electromagnets,and large superconducting magnets can be cheaper to operate because no energy is dissipated as heat in the windings. They are used in MRI instruments in hospitals,and in scientific equipment such as NMR spectrometers,mass spectrometers,fusion reactors and particle accelerators. They are also used for levitation,guidance and propulsion in a magnetic levitation (maglev) railway system being constructed in Japan.
Yttrium barium copper oxide (YBCO) is a family of crystalline chemical compounds that display high-temperature superconductivity;it includes the first material ever discovered to become superconducting above the boiling point of liquid nitrogen [77 K ] at about 93 K.
Paul Ching Wu Chu is a Chinese-American physicist specializing in superconductivity,magnetism,and dielectrics. He is a professor of physics and T.L.L. Temple Chair of Science in the Physics Department at the University of Houston College of Natural Sciences and Mathematics. He was the president of the Hong Kong University of Science and Technology from 2001 to 2009. In 1987,he was one of the first scientists to demonstrate high-temperature superconductivity.
The National High Magnetic Field Laboratory (MagLab) is a facility at Florida State University,the University of Florida,and Los Alamos National Laboratory in New Mexico,that performs magnetic field research in physics,biology,bioengineering,chemistry,geochemistry,biochemistry. It is the only such facility in the US,and is among twelve high magnetic facilities worldwide. The lab is supported by the National Science Foundation and the state of Florida,and works in collaboration with private industry.
Niobium–tin is an intermetallic compound of niobium (Nb) and tin (Sn),used industrially as a type-II superconductor. This intermetallic compound has a simple structure:A3B. It is more expensive than niobium–titanium (NbTi),but remains superconducting up to a magnetic flux density of 30 teslas [T] (300,000 G),compared to a limit of roughly 15 T for NbTi.
David C. Larbalestier is an American scientist who has contributed to research in superconducting materials for magnets and power applications. He is currently a Professor of Mechanical Engineering and a member of the Applied Superconductivity Center at the National High Magnetic Field Laboratory at Florida State University,and serves as the Interim Chair of the new Material Science and Engineering Department in the FAMU-FSU College of Engineering. He also holds emeritus status in the Materials Science and Engineering department at the University of Wisconsin–Madison,which was his academic home until 2006.
Superconducting wires are electrical wires made of superconductive material. When cooled below their transition temperatures,they have zero electrical resistance. Most commonly,conventional superconductors such as niobium–titanium are used,but high-temperature superconductors such as YBCO are entering the market.
Amit Goyal is a SUNY Distinguished Professor and a SUNY Empire Innovation Professor at SUNY-Buffalo. He leads the Laboratory for Heteroepitaxial Growth of Functional Materials &Devices. He is also Director of the New York State Center of Excellence in Plastics Recycling Research &Innovation,an externally funded center with initial funding of $4.5M for three years at SUNY-Buffalo. He is the founding director of the multidisciplinary and transdisciplinary RENEW Institute at SUNY-Buffalo in Buffalo,New York and served as director from 2015-2021. RENEW is an internally funded research institute at SUNY-Buffalo. For his contributions to UB,in 2019,he was awarded the University at Buffalo or SUNY-Buffalo President's Medal,which recognizes “outstanding scholarly or artistic achievements,humanitarian acts,contributions of time or treasure,exemplary leadership or any other major contribution to the development of the University at Buffalo and the quality of life in the UB community.”This is one of the highest recognitions given at the university.
George Ogurek Zimmerman,was a Polish-born American scientist,researcher,inventor,professor of physics and physics department chair at Boston University. Zimmerman achieved his PhD in solid state physics in 1963 at Yale University and came to Boston University in the fall of 1963.
Laura H. Greene is the Marie Krafft Professor of Physics at Florida State University and chief scientist at the National High Magnetic Field Laboratory. She was previously a professor of physics at the University of Illinois at Urbana-Champaign. In September 2021,she was appointed to the President's Council of Advisors on Science and Technology (PCAST).
Diane McKnight is a distinguished professor of civil,environmental,and architectural engineering at the University of Colorado Boulder and a fellow at the Institute of Arctic and Alpine Research (INSTAAR). McKnight is a founding principal investigator of the National Science Foundation's Long-Term Ecological Research (LTER) program in the McMurdo Dry Valleys of Antarctica.
Venkat Selvamanickam is the M.D Anderson Chair Professor of Mechanical Engineering and a Professor of Physics at the University of Houston. He is also the Director of the Applied Research Hub of the Texas Center for Superconductivity at the University of Houston.
Rare-earth barium copper oxide (ReBCO) is a family of chemical compounds known for exhibiting high-temperature superconductivity (HTS). ReBCO superconductors have the potential to sustain stronger magnetic fields than other superconductor materials. Due to their high critical temperature and critical magnetic field,this class of materials are proposed for use in technical applications where conventional low-temperature superconductors do not suffice. This includes magnetic confinement fusion reactors such as the ARC reactor,allowing a more compact and potentially more economical construction,and superconducting magnets to use in future particle accelerators to come after the Large Hadron Collider,which utilizes low-temperature superconductors.
Philip P. DiStefano is an academic administrator who serves as the current and 11th chancellor of the University of Colorado Boulder since May 2009. He has taught at the University of Colorado,Boulder since 1974,and holds the Quigg and Virginia S. Newton Endowed Leadership chair.
Yvan J. Bruynseraede is a condensed matter experimental physicist,known for his work on multilayers and superlattices,and his interests are thin films,nanostructures,novel materials,magnetism,and superconductivity. He is currently Professor Emeritus at the Catholic University of Leuven (KULeuven),and a member of the Quantum Solid-State Physics Laboratory.
Hydrogen cryomagnetics is a term used to denote the use of cryogenic liquid hydrogen to cool the windings of an electromagnet. A key benefit of hydrogen cryomagnetics is that low temperature liquid hydrogen can be deployed simultaneously both as a cryogen to cool electromagnet windings and as an energy carrier. That is,powerful synergistic benefits are likely to arise when hydrogen is used as a fuel and as a coolant. Even without the fuel/coolant synergies,hydrogen cryomagnetics is an attractive option for the cooling of superconducting electromagnets as it eliminates dependence upon increasingly scarce and expensive liquid helium. For hydrogen cryomagnetic applications specialist hydrogen-cooled electromagnets are wound using either copper or superconductors. Liquid-hydrogen-cooled copper-wound magnets work well as pulsed field magnets. Superconductors have the property that they can operate continuously and very efficiently as electrical resistive losses are almost entirely avoided. Most commonly the term "hydrogen cryomagnetics" is used to denote the use of cryogenic liquid hydrogen directly,or indirectly,to enable high temperature superconductivity in electromagnet windings.
