LAUSR

Particle diffusion coefficient and convection velocity of ECRH plasmas have been evaluated by using a density modulation experiment in LHD. The diffusion coefficients and convection velocities were estimated by newly developed analysis method. This method combines conventional quasi-Newton optimization and genetic algorithm. The genetic algorithm finds the appropriate initial values. The appropriate initial values prevent to falling in inappropriate results which are not applicable for the transport physics such as negative diffusion coefficients or extremely high value. The diffusion coefficient obtained with the modulation experiment (D mod) in the core region increases monotonically with increase of the effective collisionality (ν * h). The experimental results of D mod and convection velocity (V mod) can reconstruct the density profile at ν * h 1.5. The values of D mod was from several times to 3 orders higher than neoclassical prediction. On the other hand, V mod was comparable with neoclassical estimation. Ion scale microturbulence was measured and compared with D mod and V mod. The comparison suggested possible linkage between two.