Session RP1 - Poster Session VIII.
POSTER session, Thursday afternoon, October 30
Fran Hill Southeast Exhibit Hall, ACC
High magnetic field experiments have shown consistently that under ohmic heating conditions, the energy confinement time tends to increase with density as long as its profile is significantly peaked. This peaking can occur spontaneously as for the Alcator A and FT experiments or be produced by injection of pellets as for the Alcator C and FTU experiments. When the profile is not peaked, the confinement time saturates as the density is increased above a value which is an increasing function of the plasma current. The values of the saturated confinement time correspond to those of the so called L-regime. Pellet injection to prevent saturation in the Alcator C experiments was suggested on the basis that Ion Temperature Gradient driven modes were responsible for most of the observed energy transport and were preventable by peaked density profile. Recent experiments by the FTU machine^2 are shown to be consistent with those performed by Alcator C originally.
^2A. Frigione et al., paper EX/P4-02, 19th Fus. Energy Conference (Lyon) 2002, publ. IAEA-CN-94.