When the ratio μli/μli is of the order of unity, electron transport fluxes such as bootstrap current can be affected by the ion orbit squeezing. Here,μli is the electron viscous coefficient, andμli is the ion viscous coefficient with the effects of ion orbit squeezing included. The condition μli/μlle≃1 can be satisfied for plasmas, such as those in enhanced reversed shear (ERS) mode, with ion temperature greater than electron temperature and orbit squeezing factor S≫ 1. Transport fluxes for both standard squeezed banana orbits and for squeezed orbits close to the magnetic axis are calculated for a large aspect ratio tokamak. It is found that ion heat flux and bootstrap current are reduced in ERS-like plasmas. Furthermore, the bootstrap current density does not vanish on the magnetic axis for a parabolic pressure profile in minor radius r due to the finite value of the fraction of trapped particles. This makes it possible to operate tokamaks in steady state.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics