“Fusion ignition,” a major milestone toward the harnessing of fusion power, is expected within the next year or two at the National Ignition Facility (NIF).

Researchers at MIT’s Plasma Science and Fusion Center figured out how to use a second fusion reaction to produce a flash of protons that allows them to see the reactions taking place inside a 2-mm diameter fuel capsule whose temperature (200 million degrees Kelvin) and pressure (a trillion times atmospheric pressure) become much greater than those at the center of the sun.

The practical harnessing of this power is thought to remain decades away.