Color reinforcement photograph of the interior of the NIF preamplifier (Credit: Damien Jemison). Springer Nature Courtesy photo
Beijing, January 27 (Xinhua) -- In a recent physics paper published in the internationally renowned academic journal Nature, researchers reported that plasma-like matter in nuclear fusion has self-heating, which is a milestone in making nuclear fusion energy a viable energy source. Nature-Physics also published an article describing the optimization of experimental design to achieve this result.
Nuclear fusion is the reaction of atomic nuclei combined to release energy, which is expected to provide sustainable energy. This is a physical process that drives stars, but it is difficult to reproduce in the laboratory and requires more energy than it can produce. One of the key steps in achieving a net fusion energy generator is the combustion of plasma, where fusion is the main source of thermal energy, and the plasma state of the fuel needs to be maintained so that it is hot enough to allow for further fusion reactions.
Corresponding author Alex Zylstra and colleagues at Lawrence Livermore National Laboratory in the United States reported this state in inertial constrained fusion experiments, in which fusion reactions are initiated by compressing and heating capsules filled with thermonuclear fuel.
NIF Target Bay, a location for the 2013 film Star Trek: The Dark Unbounded (Source: Damien Jemison). Springer Nature Courtesy photo
Experiments with the U.S. National Ignition Device (NIF) enabled the use of 192 laser beams to ignite plasma, rapid heating and implosion of target pellets containing 200 micrograms of deuterium-tritium fuel, reaching temperatures and pressures high enough to trigger a self-heating fusion reaction. Past attempts have been limited by the difficulty of controlling the shape of the plasma, making it impossible to avoid disrupting the way laser beams accumulate energy in the plasma. However, the team of authors of the latest paper has improved the experimental design so that the capsule can accommodate more fuel and absorb more energy when it contains plasma. The efficiency of these experiments (up to 170 kilojoules of energy) is three times greater than the results of previous experiments. (End)