An Edge Rotation and Temperature Diagnostic on NSTX
Authors: T.M. Biewer, R.E. Bell, R. Feder, D.W. Johnson, and R.W. Palladino
Date of PPPL Report: August 2003
Submitted to: Review of Scientific Instruments
A new diagnostic for the National Spherical Torus Experiment (NSTX) is described whose function is to measure ion rotation and temperature at the plasma edge. The diagnostic is sensitive to C III, C IV, and He II intrinsic emission, covering a radial region of 15 cm at the extreme edge of the outboard midplane. Thirteen chords are distributed between toroidal and poloidal views, allowing the toroidal and poloidal rotation and temperature of the plasma edge to be simultaneously measured with 10 ms resolution. Combined with the local pressure gradient and the EFIT code reconstructed magnetic field profile, the edge flow gives a measure of the local radial electric field.