3D character of plasma transport in the Aditya limiter scrape-off layer

Strong 3-dimensional character of plasma transport was identified in the SOL plasma of tokamak Aditya in 3D edge plasma transport simulation using the code EMC3-EIRENE. Quasi-periodic flow structure and associated density modulations are observed in the poloidal direction resulting in complex sheared flow from locations far upstream to the limiter. The modulations in plasma parameters are estimated to generate secondary drifts contributing to the SOL flows routinely measured in the device. The divergence free diamagnetic drift resulting from the quasi-periodic modulations is estimated in the SOL region and shown to result in a flow vorticity along the parallel direction, contributing to the generation of large scale structures that determine an effective cross field diffusivity in the SOL region. (author)