ECH Power Modulation Experiments in

Power deposition profile is one of the essential keys in understanding the transport mechanism in the plasma confinement devices. Using the power modulation techniques, the power deposition profile and its change in shape and position by the focal position is clearly observed experimentally in Large Helical Device (LHD). These power deposition profiles show fairly in good agreement with the results from ray tracing calculation. Such experimentally observed power deposition profiles are used as the inputs of newly developed one dimensional time dependent electron transport code to deduce the dynamic electron heat diffusivity that reproduces the experimental data. Keywords: modulation, transient analysis, transport, ECH, LH