Fusi Nuklir

Magnetically confined plasma in the Korean superconducting tokamak, KSTAR. The extreme temperature plasma radiates in a spectrum that our eyes can not see. What is visible in this image are the colder regions on the outer edge of the plasma. Photo: KSTAR. Plasma Confinement Physicists have been exploring the properties of plasmas within tokamak devices since the 1960s. The doughnut-shaped torus of the tokamak represented a major break-through in plasma science at the time: here temperature levels and plasma confinement times reached levels that had never been attained before. The ITER Tokamak chamber will be twice the size of the largest currently-functioning tokamak, with a plasma volume eight to ten times larger (830 cubic meters). Left to itself, the plasma would occupy all of the space in the chamber, however no material could withstand contact with the extreme-temperature plasma. Scientists are able to contain or 'confine' the plasma away from the walls by exploiting certain of its physical properties. Plasmas consist of charged particles - positive nuclei and negative electrons - that can be shaped and confined by magnetic forces. Like iron filings in the presence of a magnet, particles in the plasma will follow magnetic field lines. The magnetic field acts as a recipient that is not affected by heat like an ordinary solid container. In ITER, different types of magnetic fields will work in subtle combination to shape the plasma into the form of a ring - or torus - and isolate the very hot plasma from the relatively cold vessel walls in order to retain the energy for as long as possible. The vacuum vessel is the first safety confinement barrier, and will not be in contact with the plasma. Sumber: Web Resmi ITER