A Langmuir/Mach probe array for edge plasma turbulence and flow

We have installed and operated a reciprocating Langmuir/Mach probe to simultaneously measure parallel and perpendicular plasma flow profiles along with density, temperature, floating potential profiles, and fluctuating parameters such as fluctuation driven particle flux and wave number on a single shot. Plasma facing components are made from boron nitride and the probe tips are 1-mm-diam carbon cylinders. The Mach probe, designed following the Gundestrup model, has 12 probes arranged in a circular array. Four Langmuir probes mounted at the front of the Mach probe array measure floating potential, ion saturation current, and temperature. The perpendicular flow velocity measurements reduced from the Mach probe array compare well with the phase velocity measured from the proud Langmuir probes and the ErxB poloidal rotation. copyright 1997 American Institute of Physics