Scrape-Off Layer (SOL)

The SOL is the thin plasma layer beyond the last closed flux surface that carries exhaust to the divertor. Kronos widens it with Super-X geometry.

What

Open field lines outside the confined plasma

Job

Channels heat and particles to the divertor

Kronos approach

Super-X flux expansion + detachment

Companion

the divertor

The scrape-off layer (SOL) is the thin skin of plasma that lies just outside the last closed magnetic surface. Its field lines are open — they lead to the divertor targets rather than looping back — so the SOL is the channel that carries the plasma's exhaust heat and particles out of the machine.

How wide and how cool the SOL is determines whether the divertor survives. Kronos MetroVolt widens the exhaust channel with a Super-X magnetic geometry that spreads the heat over more area, and relies on detachment — radiating the power away before it reaches the target. Managing the SOL is inseparable from the ELM-free edge the design depends on.