Plasma stability promised with compact fusion deviceS. Himmelstein | April 15, 2019
Sustaining controlled thermonuclear fusion usually requires large and expensive magnetic field coils to stably confine burning plasma, ionized nuclei that collide to initiate nuclear fusion. A tabletop-sized fusion system based on Z-pinch technology has been engineered as a less expensive and more manageable approach to nuclear fusion.
This method compresses, or pinches, a flowing plasma using electromagnetic forces, which drive the plasma to higher temperatures and densities. Researchers from University of Washington and Lawrence Livermore National Laboratory used the system to sustain nuclear fusion from a 50 cm long plasma column.
This plasma confinement concept developed in the 1950s had been largely abandoned because of the unstable nature of the plasmas produced. The research team applied a sheared axial flow force to the deuterium-hydrogen-based plasma as it advanced through the accelerator. This generated a radial flow that maintained and stabilized the plasma for about 16 μs, or 5,000 times longer than static plasmas. During this stable period, the presence of high-energy neutrons expected from a fusion reaction was observed for a period of 5 μs.
This research, published in Physical Review Letters, highlights the potential use of a Z-pinch in future compact fusion-energy generators.