Survey of Lower Hybrid Experiments

Recent results in lower hybrid experiments on tokamaks are surveyed. Both ion and electron heating regimes are examined. It is found that while good coupling of the RF power with multiple waveguide arrays can be achieved, the ion heating results tend to be irreproducible. Electron heating in high density plasmas, such as in Alcator C, tend to be efficient and reproducible. Perhaps the most exciting results have been obtained in RF current generation experiments where toroidal currents of the order of hundreds of kiloamperes have been generated by injecting several hundred kilowatts of power via traveling lower hybrid waves.