Abstract
The magnitude of the radial electric field (Er), resulting from nonambipolar fluxes of neoclassical origin, is evaluated using Monte Carlo guiding-center simulations for a low-current plasma corresponding to the FT-2 tokamak {Fisichiskii Tokamak-2, Ioffe Institute, St. Petersburg [S. I. Lashkul, V. N. Budnikov, E. O. Vekshina et al., Plasma Phys. Rep. 27, 1001 (2001)]}.
The Er-values are found to significantly exceed those given by the standard neoclassical theory, based on thin-orbit assumption, when the plasma current is sufficiently low and the pressure gradient is sufficiently high.
Strong Er-structures are found to form in the same low plasma-current range where enhanced confinement is reported in the FT-2 tokamak. In the simulations, the physics behind the strong increase in the field values is intimately related to the poloidal Mach-number, together with the wide ion orbits.
The Er-values are found to significantly exceed those given by the standard neoclassical theory, based on thin-orbit assumption, when the plasma current is sufficiently low and the pressure gradient is sufficiently high.
Strong Er-structures are found to form in the same low plasma-current range where enhanced confinement is reported in the FT-2 tokamak. In the simulations, the physics behind the strong increase in the field values is intimately related to the poloidal Mach-number, together with the wide ion orbits.
| Original language | English |
|---|---|
| Article number | 072510 |
| Journal | Physics of Plasmas |
| Volume | 14 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - 2007 |
| MoE publication type | A1 Journal article-refereed |
Keywords
- plasma transport processes
- Tokamak devices
- ToKamak
- plasma toroidal confinement
- plasma flow
- plasma simulation
- Monte Carlo methods
- plasma pressure
- Mach number
- fusion energy
- fusion reactors