Abstract
Fast wave current drive has been used to substantially modify the central current density profile in a tokamak plasma. Counter-fast wave current drive (FWCD) applied to discharges with negative central magnetic shear enhances the shear reversal and leads to a distinct transition to a mode of improved core confinement. In this state, the electron thermal diffusivity decreases by \(50+/-20\)% and the ion diffusivity by \(80+/-20\)%, compared to just before the transition. The FWCD and electron heating elucidates the role of the current profile on confinement and stability.
Original language | English |
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Pages (from-to) | 3141-3144 |
Number of pages | 4 |
Journal | Physical Review Letters |
Volume | 77 |
Issue number | 15 |
DOIs | |
State | Published - 1996 |
Externally published | Yes |