In this work we describe the heating results in the LH frequency range (f = 2.45 GHz, Pw 5 250 kW, P < 6 k_W/cmz) both in the electron and ion regimes. Efficient electron heating was observes f o r n 5 5 ~1 0 ' ~ c w 3 . Increases of the peak electron temperature up to 700 eV were measured. At higher densities the interaction with electrons disappears. In the ion regime fast neutral tails and neutron enhancement were observed. The influence of plasma boundary conditions on the penetration of the wave is demonstrated. The principal physical problems are pointed out and some possible conclusions are given.

The energy confinement of plasma in FT (Frascati Tokamak) has been studied in a wide range of plasma currents (Ip up to 550 kA) and densities (n̄ up to 4.5 × 1014 cm−3). The Lawson parameter n̂τE has reached a value of 4 × 1013 cm−3 ·s. The main objective was to investigate the limits of validity of the linear relationship between confinement time and density. The ion heat flux has been found to be consistent with neoclassical ion transport. The electron heat diffusion coefficient has been found to increase with plasma current. Indeed, the electron thermal diffusion coefficient has been shown to be approximately proportional to the electron drift parameter (vD/vth). Thus the linear relationship of the electron energy confinement time with density holds only for discharges with the same current. – The deviation from a linear dependence of the totalenergy confinement time on density is due to ion transport and, therefore, appears to be a neoclassical effect.

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