Divertor-Free Exhaust

A tokamak needs a divertor to handle exhaust on closed field lines; the linear burner exhausts naturally out its open ends instead.

No divertor to build

In a tokamak, closed field lines mean exhaust particles and heat must be steered onto a divertor — a heavily loaded, actively cooled target that is one of the hardest components in the machine. A tandem mirror has open field lines: the exhaust simply flows out the ends. There is no divertor, and the exhaust-handling problem is transformed into an opportunity.

The ends are the exhaust

Plasma leaking past the plugs streams into the expander, where the field expands to spread the heat and order the flow. That flow then lands on the direct converter, which extracts its energy as electricity. So the burner's exhaust surface is a generator, not a sacrificial target.

Why this simplifies the machine

• No divertor cassette, no complex exhaust magnetics
• Heat flux is reduced by field-line expansion rather than by exotic targets
• Exhaust energy is recovered instead of discarded
• Off-normal plasma dumps out the ends rather than onto in-vessel components

This is one of the structural advantages of choosing a linear geometry. It removes a component that dominates tokamak engineering and turns the unavoidable end losses of a mirror — historically its weakness — into the machine's power-extraction path when paired with direct conversion.

Removing the divertor also removes one of the largest single sources of downtime and engineering complexity in tokamak concepts, an advantage described here only in engineering terms — fewer critical components and simpler exhaust handling.