DT Fusion Ignition of LHD-Type Helical Reactor by Joule Heating Associated with Magnetic Axis Shift

摘要

A new concept to achieve current drive with magnetic axis shift, which is caused by vertical magnetic field coil current change in LHD-type magnetic configuration, is proposed. It is confirmed numerically that an LHD-type helical fusion reactor can be ignited by high-current Joule heating. MHD stability of the plasma current in a helical system is analyzed theoretically. Large plasma current that flows in the opposite direction of the helical coil current is MHD stable. Currents with a hollow current profile are more stable than those with a flat-top profile. The central peak current profile will be redistributed to the hollow current profile. A new concept involving the current-driven and current-less hybrid operational scenario of an LHD-type helical reactor is discussed.