Evolution of intrinsic flows and radial electric field in HSX stellarator*

The inboard/outboard asymmetry in impurity ion flow on the HSX stellarator is measured by the Charge Exchange Recombination Spectroscopy (CHERS) diagnostic. This allows the calculation of the bootstrap and Pfirsch-Schluter flows on a flux surface. The evolution of bootstrap flows has been measured in the HSX stellarator and compared with the evolution of bootstrap current. The flow evolution was found to be dependent on magnetic configuration and plasma parameters, while the electric field was found to be constant in time. With 50 kW ECRH heating, the bootstrap flow decreased from 13 to 8 km/s from the beginning to the end of the discharge in the core of the plasma (r/a of .2) while the electric field remained constant at 2.5 kV/m. The Pfirsch-Schluter flow measurements are used to find the radial electric field. These measurements of radial electric field are compared the neoclassical values calculated by the PENTA[1]. [1] J. Lore at al., Phys. Plasmas 17 (2010) 056101