Progress in Doppler Velocity Measurements of Ions in the DIII-D Divertor and SOL
POSTER
Abstract
We present recent progress in Doppler velocity measurements of ions using coherence imaging. A new in-situ calibration technique has been developed, focusing on CIII emission (465nm), and an optimized tomographic inversion routine provides time-resolved ($\sim$2 ms) flow images between shots. The CIII flow velocity in the divertor changes direction in response to a change in the sense of the DIII-D toroidal field, indicating the importance of drifts; the details of the flow image also changes near the x-point. Initial comparisons with UEDGE modeling will be presented. A second polarization interferometer system has been installed on the LLNL wide-view periscope, providing a tangential view of the scrape-off region around the plasma core. Initial measurements with a high spatial resolution camera (5.5 Megapixel) with $\sim$10 ms time resolution will be presented. Both systems have a remote filter wheel to select visible impurity lines, e.g. CIII, CII, along with the main ion in Helium plasmas.
*Work supported by the US Department of Energy under DE-FC02-04ER54698 and DE-AC52-07NA27344.