| Term | Definition |
|---|---|
| earthing | See “grounding”. |
| EB | electron beam, a means of welding or cutting materials. |
| ECCD | Electron cyclotron current drive, see ECRH. Momentum can also be transferred to the plasma and if directed properly it can contribute to driving plasma current. |
| ECH | electron cyclotron heating, see “ECRH” |
| ECM | electrochemical machining |
| ECRH | Electron cyclotron resonance heating, the application of external power to the plasma at one of the frequencies at which waves propagate in the plasma. The EC resonance is the frequency with which electrons orbit the field lines, so enhancing that oscillation adds energy to the plasma ions by subsequent collisions. |
| ECW | electron cyclotron wave, the wave emitted by the electron cyclotron antenna. |
| EDA | (ITER) Engineering Design Activities, conducted from July 1992 to July 2001. |
| edge fluctuations | Fluctuations in either density or electric field occurring at the boundary of a plasma. |
| edge localized mode | (ELM), the rapid transition between H-mode and L-mode; fluctuation at the plasma boundary associated with magnetohydrodynamic instabilities. |
| edge physics | Plasma physics devoted to studying the boundary of a particular plasma. |
| EFDA | European Fusion Development Agreement. Also refers to the organisations established under that agreement, such as the Close Support Units (CSUs) for ITER (in Garching) and JET(in Culham). |
| effective dose | The sum of the equivalent dose over tissues and organs, weighted by the tissue weighting factor. Expressed in sieverts (Sv). |
| effluent | A fluid waste (liquid or gas) which is released into the environment. |
| electrical discharge machining | (EDM), a spark erosion technique in which metal is removed as sparks pass between a shaped electrode and the work. Can be used for machining irregular holes, etc. |
| electro-mechanical load | Totality of all electromagnetic and mechanical loads. |
| electrochemical machining | (ECM), removing material from a metal by anodic dissolution in a bath, in which electrolyte is pumped rapidly through the gap between the shaped electrode and the stock. |
| electromagnetic loads | Movement of the current-carrying plasma induces currents flowing in continuous conducting paths in the surrounding structure. These induced currents create mechanical loads on the structures themselves and their joints. The loads can be especially large during rapid plasma current change, such as startup and ramp-down of plasma current, or in the various cases of disruption or vertical displacements of the plasma. |
| electron beam | A stream of electrons moving with the same velocity and direction in neighbouring paths and usually emitted from a single source such as a cathode. |
| electron cyclotron current drive | (ECCD), a technique to drive current noninductively by using radio-frequency waves at the electron cyclotron frequency. |
| electron cyclotron frequency | The frequency (usually microwave) of radio waves which have the same frequency as electrons orbiting magnetic field lines, such as those in a tokamak. |
| electron cyclotron resonance heating | (ECRH), a mode of heating a plasma by resonant absorption of energy based on the waves induced in the plasma at the cyclotron frequency of electrons. |
| electron cyclotron wave | (ECW), A wave in a plasma which propagates parallel to the magnetic field produced by currents outside the plasma at frequencies less than that of the electron cyclotron resonance, and which is circularly polarized, rotating in the same sense as electrons in the plasma; also known as whistler wave. |
| ELM | edge localized mode, low amplitude oscillation and energy loss at the plasma edge caused by MHD instability. Various types can occur, some causing more energy loss than others. |
| ELMy H-mode | A period of improved energy confinement in the plasma accompanied by relatively low level instabilities localised at the plasma edge which help to maintain thermal equilibrium in the plasma. See also H-mode. |
| empirical scaling formulas | Formulas relating key parameters related to change in plant characteristics which are derived primarily from observation of the plant rather than from a deep physical understanding or theoretical model of the underlying driving processes. |
| energy confinement time | The ratio of instantaneous plasma energy content to the net power flow into the plasma required to maintain that energy content. |
| energy confinement time scaling law | A usually empirical scaling formula, based on major machine parameters , which predicts the energy confinement time for, other experiments and conditions. |
| energy transport | The thermal conductivity and convection rates in a plasma. |
| engineering change | EC, an approved change to the design baseline. An Engineering Change Proposal (ECP) is a recommended Engineering Change. |
| Engineering Design Activities | EDA, the project phase in which the ITER design was mainly developed. |
| enhanced particle modes | EPMs, mhd activity in which certain particles species are accelerated. |
| EOB | end of burn |
| EPS | European Physical Society Conference on Controlled Fusion and Plasma Physics |
| EPTR | Engineering Problems of Thermonuclear Reactors |
| equatorial plane | The horizontal level determined by one half of the height of the toroidal field coils. |
| equatorial port extension | Equatorial ports of the main ITER vacuum vessel each consist of a hole in the vessel itself, a “port stub” which is welded to the rim of the hole and a straight section, the “port extension”, welded to the port stub. |
| equilibration times | The time it takes for electrons and ions to come into thermal equilibrium. |
| equivalent dose | In a tissue or organ, the absorbed dose weighted by the radiation weighting factor. The unit of equivalent dose is the sievert (Sv) = 1 joule/kg = 100 rem. |
| ergodic magnetic divertor | A system of helical coils at the plasma boundary to perturb the plasma edge to facilitate removal of impurities. |
| EU | European Union |
| event sequences | Accident states defined by a postulated initiating event, its further pathways of propagation, and the corresponding consequences. |
| external heating sources |
Devices which provide auxillary heat to the plasma to raise it to burn temperature. See "auxiliary heating". |
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