A group of scientists at Lawrence Livermore National Laboratory in the United States has taken an important step in the process of making nuclear fusion, the process of generating energy from stars, a viable energy source for mankind. Using a giant laser, the researchers were able to heat fusion fuel beyond the heat they injected into it, achieving a phenomenon called burning plasma.
The energy produced was modest, equivalent to batteries that power smoke detectors and other small devices, but the experiments represented a milestone in the search for new energy sources. In the study, they were able to get a hydrogen atom to be self-heating.
"If you want to build a fire, you want the fire to heat up enough so that the wood can keep burning. This is a good analogy for a burning plasma, where fusion is starting to become self-sustaining," said Alex Zylstra, an experimental physicist on the project, which is part of the U.S. Department of Energy.
The scientists directed 192 laser beams toward a small target containing a capsule about 2 mm in diameter filled with fusion fuel consisting of a plasma of deuterium and tritium - two isotopes, or forms, of hydrogen. At very high temperatures, the deuterium core and the tritium core fuse and energy is released.
Unlike the burning of fossil fuels or the process of existing nuclear power plants, fusion offers the prospect of abundant energy without pollution, radioactive waste, or greenhouse gases.