brian wang, for Next Big Future:

General Fusion is nearing significant milestones. General Fusion’s Approach is Magnetized target fusion (MTF). Magnetized target fusion is a hybrid between magnetic fusion and inertial confinement fusion. In MTF, a compact toroid, or donut-shaped magnetized plasma, is compressed mechanically by an imploding conductive shell, heating the plasma to fusion conditions.

General Fusion has a full-scale prototype [of the injectors and other subsystems], twin plasma injectors resembling five-metre-long cones, each attached to opposite ends of a three-metre-diameter sphere, would pulse a few milligrams of hydrogen gas, heat it until it becomes a plasma, and inject it into a vortex of swirling liquid metal. Electricity circulating in the plasma would create magnetic fields that bind the plasma together and confine the heat.

From there, an array of as many as 300 huge pistons attached to the sphere’s shell would act like synchronized jackhammers, ramming it at 200 km/hr. This would send shockwaves into the very centre of the chamber, compressing the hydrogen isotopes to 100 million degrees celsius — hot enough for fusion to occur, and good enough to generate clean electricity from steam turbines.

General Fusion reached its milestones on the piston timing about two years ago. Technicians are now perfecting functionality of the plasma injectors.

A well-sourced update.