Reducing Instabilities in Nuclear Fusion Machine
In the core of every star burns a nuclear furnace, fusing small atoms into larger ones and releasing energy in the process. For decades researchers have been trying to initiate nuclear fusion on Earth to harness that energy for our use, but it is not easy and often takes more energy to start the fusion than it produces. Researchers at Sandia National Laboratories though have recently discovered a phenomenon that could make one method of achieving fusion significantly more efficient.
Among the experiments at Sandia is the Z machine, which is meant to collapse small cylinders of deuterium with magnetic fields so rapidly, that the atoms fuse. One issue with this technique has been magnetic instabilities forming within the cylinders, causing them to not collapse uniformly. This causes energy to be lost as not all of the deuterium will be fused. The researchers discovered that by adding a pair of Helmholtz coils to the Z machine, they could alter the geometries of instabilities and minimize their affects. Without the magnetic fields from the Helmholtz coils, the instabilities pass horizontally through the cylinder, crumpling its sides, but with the fields the instabilities take on a helical shape. That insulates the cylinder from crumpling before the deuterium fuses, and thus reduces the amount of energy lost.
As significant the reduction in energy loss is, there is still a long way to go before fusion could be used as a power source.
Source: Sandia National Laboratories