Super conductivity General propertiesObservations regarding Applications
Super conductor are the material having almost zero resistivity and behave as diamagnetic below the super conducting transition temperature. Super conductors are PERFECT conductors.
Virtually zero electrical resistance. Perfect diamagnetic property. Critical field depends upon temperature of superconducting material. Heavy current effect destroys superconductivity properties. At very high pressure Tc is directly proportional to pressure. Tc is inversely proportional to square root of At.wt of the isotope of single superconductor.
LONDON THEORY -1935 GINZBURG-LANDAU THEORY – 1950 BARDEEN, COOPER, SCHRIEFFER THEORY - 1957
Principle: The electron experience a special kind of attractiveinteraction, over coming the coulombs force of repulsion betweenthem, as a result cooper pairs are formed. At low temperature , these pairs move through latticewithout resistance and hence behave as superconductor.
Can carry large quantities of energy without heat loss. Able to generate strong magnetic fields. Superconductors beneficial applications in medical imaging techniques. New superconductive films may result in miniaturization . Superconductors increased speed in computer chips.
Superconducting materials conduct current at only given temperature known as transition temperature. Superconductorsstill do not show up in most everyday electronics.
Principle: Persistent current in D.C voltage.Construction: A thin layer of insulators is placed between thesuperconductors. Both superconductors are connected to a battery .Working : LET US SEE THE WORKING OF JOSEPHDEVICE IN THE SUCCEEDING SLIDES.
Super conducting generator Super conducting transmission line cables Superconducting magnetic energy storage system (smes)
Converts mechanical to electrical energy. Own magnetic field is produced. Current and flux density determines the output. Field windings produces higher magnetic field. Superconductors have extremely high current carrying capacity.
Provides ZERO resistance. Due to LOW VOLTAGE, high current transmission occurs. SMALL physical size. Reduced CLEARANCE for terminal faculties. Quick RECOVERY after fault. Overload capability.
Current carrying wire generates a magnetic field. Superconducting solenoids made by wrapping a superconducting wire in the coil from are functionally superior to conventional solenoids. Zero DC electrical resistance. No resistive losses.