Noninductive Current Driven by Electron Cyclotron Waves in a Magnetically Confined Plasma O. Sauter et al. Nuclear fusion in a doughnut. The TCV reactor in Lausanne holds hydrogen plasma as hot as 100 MK . Researchers there have demonstrated a technique for driving plasma current that is expected to be part of future fusion-based power plants.
Fusion power promises a clean and almost inexhaustible source of energy.
Physicists developing the tokamak type of reactor have made progress over the past few decades, but several challenges remain. Now a Swiss team reports in the 10 April PRL that they have successfully tested what may be the most promising technology for the steady-state mode. They aimed carefully tuned microwave beams into a tokamak and drove a controlled plasma current without help from the usual pulsed technique. Although this current lasted for only about two seconds, the time was limited only by the pulse length of the microwaves, which in principle could be very long. For a tokamak to produce useful power, magnetic fields must confine the hydrogen plasma at a sufficient temperature and density and for a long enough period of time.