Session RP1 - Poster Session VIII.
POSTER session, Thursday afternoon, October 30
Fran Hill Southeast Exhibit Hall, ACC
Langmuir probes have been used to characterize the edge plasma and turbulence in the Helically Symmetric eXperiment (HSX) stellarator. Power spectra of ion saturation current and floating potential (measured on the low field side of HSX) display broad frequency content. Electrostatic particle transport spectra deduced from these signals show a significant contribution for frequencies up to 300 kHz. Total electrostatic particle transport in the edge is approximately 10^16 cm-2s-1 in the outward radial direction, increasing with decreasing radius. Within r/a \sim0.7, a mode at 40-50 kHz is apparent and is responsible for a fraction (<20%) of the particle transport. Phase velocities of the fluctuations are calculated via the two-point correlation technique to be in the ion diamagnetic direction and decrease as the EŽB velocities (also in the ion diamagnetic direction) decrease. First electrostatic transport measurements from a probe with access to the high field side of HSX will be presented