Session GP1 - Poster Session IV.
POSTER session, Tuesday afternoon, October 30
Exhibit Hall B,
Enhanced plasma performance has been obtained on the Frascati Tokamak Upgrade at high field (7.2 - 8 T) and high current (0.8-1.25 MA) by multiple deuterium pellet injection. Improved confinement and enhanced neutron rate were associated with an increase of the sawtooth period occurring when a significant portion of the ablated deuterium was deposited near the inversion radius. Reproducible access to the enhanced regime was achieved by adjusting the delay between the first two pellets, as plasma cooling by the first pellet increased the deposition depth of the second one. The enhanced regime was sustained for several resistive diffusion times by injecting more pellets with optimised timing. Density profile peaking keeps increasing for more than one confinement time after pellet ablation. The net particle flux is well below the neoclassical prediction, so that an anomalous particle pinch is needed to explain the observed profile evolution. Results of energy and particle transport analysis will be presented.