Physicists led by Jeff Lestz at General Atomics in San Diego demonstrated helicon current drive in a fusion experiment for the first time. They steered radio waves around a donut-shaped tokamak so the confined plasma absorbed them, producing an electric current inside the plasma itself.
Tokamaks normally rely on pulses of current, so today's designs would run in bursts rather than nonstop. If radio waves can sustain that current continuously, future reactors could operate steadily, a practical requirement for fusion to deliver reliable electricity to the grid.
✦ Radio waves may keep fusion reactors running without pause.