Observations of Anisotropic Ion Temperature in the NSTX Edge during RF Heating

Biewer, T.M. ; Bell, R.E. ; Ryan, P.M. ; Wilson, J.R.

Princeton University. Plasma Physics Laboratory.

关键词: Heating;    Rotation;    Auxiliary Heating;    Magnetic Fields;    Rf Heating;   

DOI  :  10.2172/828257
RP-ID  :  PPPL-3973
RP-ID  :  AC02-76CH03073
RP-ID  :  828257

美国|英语

来源: UNT Digital Library

【 摘 要 】

A new spectroscopic diagnostic with both toroidal and poloidal views has been implemented in the edge of the National Spherical Torus Experiment (NSTX). This edge rotation diagnostic (ERD) was designed to measure the velocity and temperature of ions. The intersection of the diagnostic sightlines with the intrinsic emission shell provides the localization of the measurement. There are 7 toroidally directed views and 6 poloidally directed views of the outboard plasma edge. The poloidal view is {approx}20 cm (toroidally) from the RF antenna, and the toroidal view is {approx}2 m away. The sightlines are nearly tangent to the flux surfaces. The C{sup 2+} triplet near 4651 {angstrom} and the He{sup +} line at 4685 {angstrom} are measured. In the results presented here, helium is the bulk, ''working'' ion of the discharge. The NSTX is a large spherical tokamak with a major radius of 0.85 m and a minor radius of 0.65 m. The outer walls and center-stack are lined with protective carbon tiles. Pulse lengths for these NSTX discharges are {approx} 600 ms, with an on-axis toroidal magnetic field of {approx} 0.3 T. The plasma current is 500 kA. The on-axis electron temperature and density are {le} 2 keV and {approx} 2 x 10{sup 19} m{sup -3}, respectively with {le} 4.3 MW of High Harmonic Fast Wave (HHFW) Radio Frequency (RF) auxiliary heating.