Integrated transport simulation of LHD plasmas using TASK3D

An integrated transport simulation code for the helical plasma, TASK3D, is developed and applied to the LHD plasma. The neoclassical transport in the helical plasma is evaluated by the neoclassical transport database, DGN/LHD, which is constructed using a neural network technique. In addition to the neoclassical transport, five anomalous transport models (the Bohm and edge Bohm models, Gyro-Bohm and Gyro-Bohm like models, and Alcator model) are included and compared the temperature profiles with experimentally observed plasmas. We also take into account the differential equation for the radial electric field into TASK3D. The obtained electron and ion thermal diffusivities with the Alcator, Bohm, and gyro-Bohm models indicate the anomalous transport dominates in the electron thermal transport, while the neoclassical transport plays a crucial role in the ion thermal transport. The TASK/TX module, which solves the flux-surface averaged multi-fluid equation, is also applied to the LHD plasma to describe the time evolution of the radial electric field and the plasma rotation as well as the density and the temperature. The transition between the electron and ion roots, and the radial structure of the electric field have been demonstrated self-consistently. (author)