Heliotron J projectThe goals of the Heliotron J experiments[1,2] are:
(a) To explore the concept of the non-symmetric quasi-isodynamic optimization approach to the helical axis heliotron line,
(b) To establish the design principle for the proof of principle facility based on this concept,
(c) To understand the physics that is specific to the helical axis heliotron.
The experimental programme is organized to study the high-level compatibility between good particle confinement and MHD stability, as well as its divertor scheme for particle and heat exhaust on this confinement concept.
The design features of Heliotron J are the reduced neoclassical transport (near the tokamak level according to the numerical code DKES) and the enhanced averaged beta limit (4% for the Mercier criterion) with the small bootstrap current. The flexibility of magnetic configuration has the capability of controlling confinement properties including neoclassical/turbulence transport and divertor schemes, e.g. island/helical divertor configurations. .
Helical or helical axis heliotrons with continuous helical coils and advanced stellarators with modular coils, such as W7-X, HSX, and CFQS(CHS-qa), constitute complementary approaches to helical system development. All the approaches are needed to develop a physics and engineering understanding of the helical confinement system and to realize a future fusion reactor.
 M.Wakatani et al, "Study of a helical axis heliotron"
 T.Obiki et al, "First plasmas in Heliotron J"
 T.Mizuuchi et al, "Structure of Edge Magnetic field in Heliotron J"