Transport processes in the region close to the magnetic axis in quasihelically symmetric stellarators are investigated by solving fluid and kinetic equations. It is found that the isomorphic transformation between transport fluxes in quasihelically symmetric stellarators and those in tokamaks is still valid if the dependence of the Fourier amplitude of the magnetic field spectrum on the flux function does not transform accordingly, and if the absolute values are employed in the transformations of orbit size and fraction of trapped particles. It is also found that orbit squeezing effects are less effective in quasihelically symmetric stellarators because the size of the orbit is smaller than that in tokamaks. The bootstrap current density does not vanish on the magnetic axis if dp/dψ remains finite. Here, ψ is the toroidal flux function and p is the plasma pressure. The direction of the bootstrap current density is also opposite to that in tokamaks similar to that in the core region.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics