1.28.2013
CENTRE POST
A current-carrying central rod placed down the symmetry axis of a spherical tokamak to produce the toroidal field. This is a crucial component determining the economics of fusion power from spherical tokamaks.
1.26.2013
DBTT
As a material is cooled a temperature is reached at which it loses its ductile properties and becomes brittle. This ductile-to-brittle transition temperature (DBTT) is a key factor in the development of fusion structural materials because its value increases under irradiation. The development of steels that retain a DBTT below the lowest working temperature encountered during operational shutdowns is a major materials objective.
N. CORTEZ
N. CORTEZ
VEGISVEIEN
A method of driving plasma current that does not depend on transformer action (e.g. by using RF waves or neutral beams); necessary for a continuously operated power plant, since transformer action is cyclic. Also applied to control instabilities and to optimise confinement.
10.02.2012
DENSITY FUNCTIONAL THEORY
Density functional theory is a successful approach for describing the ground state properties of metals, semiconductors, and insulators, for both standard bulk materials and more complex materials. The interacting system of electrons is described via its density and not via its many-body wave function. For N electrons in a solid this means that the basic variable of the system depends only on the three spatial coordinates, rather than 3N degrees of freedom.
WWW.TOURNEFORTIA.COM
9.29.2012
OHMIC HEATING
Heating in addition to Ohmic heating. Used to heat tokamaks to temperatures at which Ohmic heating is no longer efficient. Usually involves the use of neutral beams of high energy particles or radio-frequency waves.
9.28.2012
9.27.2012
9.24.2012
9.22.2012
9.20.2012
COLLISIONALITY
A measure of how frequently collisions occur in a tokamak plasma. A collisionality of unity corresponds to a trapped particle performing a single banana orbit before being scattered. The collisionality drops as the plasma temperature rises.
9.18.2012
9.10.2012
9.06.2012
9.05.2012
MARK OLIPHANT
"All the hydrogen burns into helium in 10 million years.... All the helium burns to carbon in 1 million years.... Again, the star starts to collapse, because there's no more fuel. But then it heats up and the carbon starts to burn ... to form neon and nitrogen. And all of the carbon in the star burns in 100 thousand years.... And you get to oxygen. Oxygen ... burns to silicon in 10 thousand years. It's getting hotter and hotter and hotter. Less efficient. And then when all the oxygen burns to silicon, you're in the last day of the star because, remarkably, it is so hot at that point that all of the silicon in the center of the star, many thousands of times the mass of the Earth, burns to form iron in one day.... Iron can't burn to form anything. Iron is the most tightly-bound nucleus in nature. So once that's happened, there's no more fuel... When all the silicon has burned to iron, suddenly the star realizes there's no place left to go and that interior of the star, which has been held up by the pressure of nuclear burning, collapses. That whole collapse happens in one second.... There's a shock wave and that shock wave ... spews out all of the atoms that were created during the life history of a star. The carbon, the nitrogen, the helium, the iron. And that's vitally important, because every atom in your body was once inside a star that exploded.... The atoms in your left hand probably came from a different star than in your right hand, because 200 million stars have exploded to make up the atoms in your body."
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