Application Of The Elliptic Approximation Model For The Edge Turbulence Rotation Measurement Via The Poloidal Correlation Reflectometer In Wendelstein 7-X

The perpendicular velocity (v (perpendicular to)) of turbulence is measured by means of a hopping poloidal correlation reflectometer diagnostic for the study of turbulence rotation in the plasma edge region in Wendelstein 7-X. An elliptic approximation (EA) model is applied for calculating the space-time correlation in the edge region. The v (perpendicular to) profile is compared in the high-iota (edge iota approximate to 1.2) and limiter (edge iota < 1) configurations. It is found that the v (perpendicular to) gradient is inversely proportional to the heating power in the high-iota configuration, which could be attributed to the turbulence activities in the plasma edge. In the limiter configuration, the v (perpendicular to) spike is observed near the island boundary, which is corresponded to the plasma current crash. In the standard configuration (edge iota approximate to 1), the v (perpendicular to) profile in the island region distributes as a function of the perpendicular separation. With increasing of the plasma current, the island enlarges the size as is referred from the v (perpendicular to) scope, accompanying with steepening of the v (perpendicular to) gradient at the boundary of the island.