gnetic field lines will occur from the collisions between the particles. The net effect is to transport energy from the hot core to the wall. This transport process, known as classical diffusion, is theoretically not strong in hot fusion plasmas and is easily compensated for by heat from the alpha particle fusion products. In experiments, however, energy is lost from plasma more rapidly than would be expected from classical diffusion. The observed energy loss typically exceeds the classical value by a factor of 10-100. Reduction of this anomalous transport is important to the engineering feasibility of fusion. An understanding of anomalous transport in plasmas in terms of physics is not yet in hand. A viewpoint under investigation is that the anomalous loss is caused by fine-scale turbulence in the plasma. However, turbulently fluctuating electric and magnetic fields can push particles across the confining magnetic field. Solution of the anomalous transport problem involves research into fundamental topics in plasma physics, such as plasma turbulence. Many different types of magnetic configurations for plasma confinement have been devised and tested over the years. This has resulted in a family of related magnetic configurations, which may be grouped into two classes: closed, toroidal configurations and open, linear configurations. Toroidal devices are the most highly developed. In a simple straight magnetic field the plasma would be free to stream out the ends. End loss can be eliminated by forming the plasma and field in the closed shape of a doughnut, or torus, or, in an approach called mirror confinement, by "plugging" the ends of such a device magnetically and electrostatically. In the inertial confinement a fuel mass is compressed rapidly to densities 1,000 to10,000 times greater than normal by generating a pressure as high as 1017 pascals for periods as short as nanoseconds. Near the end of this time period the implosion speed ex...
