Glossary E-I

E-beam evaporation Electron beam evaporation. Method by which a substance is vaporized by bombarding it with electrons.
Electropolishing Sometimes called reverse electroplating, this is an electrochemical process which polishes a metal surface by removing a microscopic amount of material from the work piece. Used on some radio frequency particle accelerator cavities.
Expitaxial A thin film with the same crystal structure as the substrate it was grown on. The property of superconductor materials to grow this way is used to get films with good grain alignment.
Ex-situ "Out of place." In wire manufacturing, when the superconducting material is formed, then put into place. Compare In-situ.
Fault Current Limiter Device to reduce a fault current in an electrical power system.
FCL See fault current limiter
Flux lattice Magnetic flux lines in a superconductor arrange themselves into a regular lattice.
Flux lines Lines of magnetic flux inside a superconductor. Also known as vortices because the current spirals around them. These form a lattice structure, and flow through the material as the magnetic or electric field changes. The motion of flux lines dissipates energy and destroys the superconductor state. As the external magnetic field increases, the number of lines will increase, until the superconductor is full of them and the superconductor state is destroyed.
Flux Pinning Preventing the movement of flux lines within a superconductor. This prevents destruction of superconductivity, and can be achieved by defects in the superconductor structure.
Flux Qubit Micro-metre sized loops of superconducting metal interrupted by a number of Josephson junctions. Used to perform computations with qubits.
Fluxon Quantized line of magnetic flux.
Four-point Probe The most common method of determining the TC of a superconductor. Wires are attached to a material at four points with a conductive adhesive. Through two of these points a voltage is applied and, if the material is conductive, a current will flow. Then, if any resistance exists in the material, a voltage will appear across the other two points in accordance with Ohm’s law (voltage equals current times resistance). When the material enters a superconductive state, its resistance drops to zero and no voltage appears across the second set of points. By using the four-point method, instead of just two points, resistance in the adhesive and wires can be ignored; as the second set of points do not themselves conduct any current and can, therefore, only reflect what voltage exists across the body of the material. (from
Free path length Mean distance a electron will travel through a material without interacting.
FRP Fiber-reinforced plastic
FWHM Full width at half maximum
giant flux creep Large thermal decay of current observed in high Tc superconductors (HTS).
Grain Single crystal of superconductor material.
Grain Alignment Orientation of grains to one another, less than 4o angle is best for superconductor.
Grain Boundary Boundary between superconductor grains.
GZO Gadolinium zirconium oxide, a buffering/texturing material used in some IBAD processes.
H Henry. Magnetic field strength in units of Amps/meter. Related to B (magnetic flux density in teslas) via B = mH.
Hastelloy Trade name of commercial Ni-based high temperature alloys.
Hc2 Upper critical field.
High-Temperature Superconductors High temperature superconductor – ceramic materials that superconduct with a Tc of 30 K or greater. Some examples are YBCO and BSCCO. Also known as HTS.
HOP Operating magnetic field.
HTS See High-temperature superconductors.
I Current expressed in amps
I2R Joule heating, the product of the current squared times the resistance of a conductor.
IBAD Ion beam assisted deposition. A technique for depositing thin superconductor films. An ion beam is directed at an angle towards the substrate to grow textured buffer layers.
IC See critical current.
Ic Critical current of a superconductor, the maximum amount of current that can flow below a fixed electric field or resistivity criterion.
IFL I = current, FL = full load. Full load current
Index value n The n-value describes the relationship of the voltage drop across the wire to the applied current. (from
In-situ "In place." In wire manufacturing, when the precursors to the superconductor are put into place before being reacted to form the superconducting compound. Compare Ex-Situ.
IPP Independent power producer
IR Current times the resistance of a conductor; equals the voltage drop along the conductor.
Irreversibility line The line which separates the mixed state region of the H-T plane of a type 2 superconductor into two regions, below which the critical current density has a finite value and turns to zero.
ISD Inclined substrate deposition, Method for depositing a buffer onto a substrate at an angle in order to get good texturing.
I-V Current-voltage