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

Technical Report · Mon Jun 28 04:00:00 EDT 2004

DOI:https://doi.org/10.2172/828257· OSTI ID:828257

Biewer, T M ^[1]; Bell, R E; Ryan, P M; Wilson, J R

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1. Princeton Plasma Physics Laboratory

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.

• Research Organization: Princeton Plasma Physics Lab., Princeton, NJ (US)
• Sponsoring Organization: USDOE Office of Science (SC) (US)
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 828257
• Report Number(s): PPPL-3973
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
74 ATOMIC AND MOLECULAR PHYSICS
AUXILIARY HEATING
CARBON
EDGE PLASMA
ELECTRIC CURRENTS
ELECTRON TEMPERATURE
HARMONICS
HEATING
HELIUM I
ION HEATING
ION TEMPERATURE
MAGNETIC FIELDS
MAGNETIC SURFACES
PLASMA
RF HEATING
ROTATION
TRIPLETS
VELOCITY
WAVE INTERACTION
PLASMA