On the Alcator C-Mod tokamak, lower hybrid current drive (LHCD) is being used to modify the current profile with the aim of obtaining advanced tokamak (AT) performance in plasmas with parameters similar to those that would be required on ITER. To date, power levels in excess of 1 MW at a frequency of 4.6 GHz have been coupled into a variety of plasmas. Experiments have established that LHCD on C-Mod behaves globally as predicted by theory. Bulk current drive efficiencies, n20IlhR/Plh ~ 0.25, inferred from magnetics and MSE are in line with theory. Quantitative comparisons between local measurements, MSE, ECE and hard x-ray bremsstrahlung, and theory/simulation using the GENRAY, TORIC-LH CQL3D and TSC-LSC codes have been performed. These comparisons have demonstrated the off-axis localization of the current drive, its magnitude and location dependence on the launched n.

Experimental results on lower hybrid heating in the Alcator A and the Versator II tokamaks with power levels up to 90 kW are presented. In Alcator A a double waveguide grill, and in Versator II a 4 waveguide grill with arbitrary phasing are used. Also, a 6 waveguide grill experiment in Versator II is described which launches a travelling wave aimed at driving toroidal currents. The forthcoming lower hybrid heating experiment in Alcator C, utilizing four 4 x 4 waveguide arrays with power levels up to 4 MW, is also described.

The lectures given in the Summer School covered most of the important topics in controlled nuclear fusion and high temperature plasma physics. The topics are as follows: tokamak research, stellarator physics, transport and confinement of high temperature plasma, plasma-wall interaction and edge plasma physics, heating and current drive, diagnostics and general plasma theory.