The Large Helical Device can run much longer than tokamaks of similar size because it doesn’t rely on plasma current to maintain its magnetic field. Its longest discharges have lasted tens of minutes!

But achieving detachment - a state when the plasma barely touches the vessel walls — is tougher. It needs much more heating power, which usually shortens the discharge to just a few seconds.

Yesterday, we managed to keep a detached plasma going for 12 seconds #Fusion #Science #LHD

A heliotron uses continuous coils to generate a helically shaped magnetic field — basically a magnetic cage that keeps the hot #fusion plasma confined.
It’s a similar concept to the stellarator #Wendelstein7X.

The image shows the inside of the #LHD vessel — credit: NIFS.