| Term | Definition |
|---|---|
| I and C | instrumentation and control |
| IAEA | International Atomic Energy Agency, Vienna, Austria |
| IC | ITER Council; Ion Cyclotron |
| IC antenna | Heating antenna providing radiofrequency power at the ion cyclotron frequency to the plasma. |
| ICF | inertial confinement fusion |
| ICFRM | International Conference on Fusion Reactor Materials |
| ICRF | ion cyclotron radio frequency |
| ICRH | ion cyclotron resonance heating |
| ICRP | International Commission on Radiological Protection |
| ID | inside diameter |
| ignition | See “controlled ignition”. |
| impurities | Atoms of unwanted elements in the plasma usually originating from the surrounding walls. |
| in-vessel components | The in-vessel components comprise the blanket, the divertor, the fuelling and internal pumping systems, the port plugs, and diagnostic sensors mounted directly on the vessel. |
| inboard | A region located further toward the tokamak vertical centreline than the object referred to. |
| inboard plasma shape | The shape of the plasma inboard (i.e towards the machine centre) of the major circumference. This is strongly affected by the nearest poloidal field coils, usually the central solenoid. |
| Incoloy 908 | A proprietary alloy of nickel, iron, chromium, molybdenum and copper. |
| indentation | The amount of indentation in a tokamak plasma column with a "bean shaped" cross section. |
| indirect cost | 1) A cost incurred by an organization for common or joint objectives and which is not specifically identified with a particular project or activity. 2) Overhead, profits, tools, heavy equipment, warehousing and any cost related to labour other than wages, payroll taxes and benefits. |
| induction coil | A transformer for producing high voltage pulses in the secondary winding, obtained from interrupted direct current in the primary, as for a gas engine. |
| inductively driven plasmas | The basic means of driving toroidal current in the tokamak plasma uses the fact that most field lines created by the central solenoid pass down its bore and do not return on themselves until they pass outboard of (i.e radially beyond) the plasma. This “inductive linkage” between the solenoid and plasma allows a change in current in the solenoid to drive current in the plasma (Maxwell’s Laws). |
| inflatable bladder | For ITER design purposes, any metallic structure that can be inserted in a gap and subsequently pressurised to form a shim. |
| inherent safety characteristic | Achieving safety by eliminating a specified hazard by means of the choice of material or design concept. |
| insert modules | Solenoid coils which can be inserted in the bore of the CS model coil test facility in JAERI. These modules enhance the background field of the model coils allowing the highest coil fields to be reached in the insert coils,thereby testing their capability as candidate materials for the ITER CS coil. |
| inside diameter | The dimension along a diameter from one inner surface to the other (opposite) inner surface, as in a pipe, tube or cylinder bore. |
| inspection | Examination, observation or measurement to determine the conformance of materials, parts, components, systems, structures, as well as processes and procedures, with defined requirements. |
| instability | A plasma state in which any small perturbation is amplified to a considerable change in the equilibrium of the system, leading to disruptions. |
| internal mode | Magnetohydrodynamic instabilities which occur at the center of a tokamak plasma which cannot be controlled or suppressed by external means. |
| internal transport barrier | ITB, a magnetic field configuration which slows down energy conduction transverse to it. In the establishment of the H-mode, an ITB is established just inside the separatrix, helping to hold heat inside the plasma. Other ITBs have been found also inside the plasma core, although the conditions for their creation and their usefullness is not yet fully understood. |
| International Atomic Energy Agency | IAEA, an autonomous intergovernmental organization under whose auspices the ITER EDA is being conducted. |
| International Fusion Materials Irradiation Facility | IFMIF, a planned experiment in which materials and small components will be irradiated in a 14 MeV neutron spectrum, thereby testing their endurance for use in DEMO. Such materials information cannot be accumulated in ITER operation. Discussions on the cost sharing, design and location of IFMIF are underway between the major interested parties, but are not as far advanced as those on ITER. It is planned to operate IFMIF in parallel to ITER operation. |
| International Team | IT, successor for the duration of the CTA to the ITER Joint Central Team of the ITER EDA, charged with ITER design coordination responsibility. |
| International Tokamak Physics Activity | ITPA, an activity organised amongst the original ITER EDA Parties (Euratom, Japan, Russian Federation and USA) to pool information about advances in fusion physics knowledge. Run by a Physics Committee and broken into Topical Groups. |
| INTOR | International Tokamak Reactor, an international study under the IAEA; a precursor to ITER. |
| ion | An atom which has become charged as a result of gaining or losing one or more orbiting electrons. A completely ionized atom is one stripped of all its electrons. |
| ion cyclotron resonance heating | ICRH, a mode of heating a plasma by resonant absorption of energy based on the waves induced in the plasma at the cyclotron frequency of ions. Ion cyclotron resonance waves provide some 50 MW of additional heating to the ITER. |
| ion-Berstein wave | A plasma wave named after the discoverer, I.B. Bernstein. |
| ionization | The removing or adding of an electron to a neutral atom, thereby creating an ion. |
| IR | infra-red |
| ISFNT | International Symposium on Fusion Nuclear Technology |
| ISO | International Organization for Standardization |
| isotope | One of several versions of the same element, possessing different numbers of neutrons but the same number of protons in their nuclei. |
| isotope separation system | ISS, A system which supports one or more isotopes from a mixture of isotopes. In ITER, the ISS is specific to isotopes of hydrogen (i.e. protium, deuterium and tritium). |
| isotopic content | The mix of given isotopes in a mixture of isotopes, for instance the amount of tritium and other hydrogenn isotopes in a waste gas stream. |
| isotopic mass | The mass of each atom of a material in atomic mass units (see above). Thus the plasma isotopic mass for fusion is 2.5, since the fuel is basically a 50/50 mix of deuterium (2 amu) and tritium (3 amu). |
| ISS | isotope separation system |
| ITER | “The way” in Latin. Formerly interpreted to stand for International Thermonuclear Experimental Reactor, although this usage has been discontinued. |
| ITER Legal Entity | ILE, the organisation that will run ITER and which is the owner of the license to construct and operate it. The name of the organisation will be the ITER International Fusion Energy Organisation (IIFEO). |
| ITER Transitional Arrangements | ITA, the phase of ITER between Coordinated Technical Activities and the establishment of the ILE. |
| ITER Units of Account | IUA, one ITER Unit of Account is equivalent to 1000 US$ at January 1989 values. |
| ITER-FEAT | The name initially used for the final design of ITER to distinguish it from the design completed in July 1998. This term is no longer used. |
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