Measurement of Poloidal Velocity on the National Spherical Torus Experiment

Ronald E. Bell and Russell Feder

关键词: CHARGE EXCHANGE;    CROSS SECTIONS;    DIMENSIONS;    ELECTRIC FIELDS;    HEATING;    PLASMA;    RECOMBINATION;    RESOLUTION;    SPECTRA;    SPECTROMETERS;    SPECTROSCOPY;    VELOCITY NSTX;   

DOI  :  10.2172/981719
RP-ID  :  PPPL-4525
PID  :  OSTI ID: 981719
Others  :  TRN: US1004098

学科分类：原子、分子光学和等离子物理

美国|英语

来源: SciTech Connect

【 摘 要 】

A diagnostic suite has been developed to measure impurity poloidal flow using charge exchange recombination spectroscopy on the National Spherical Torus Experiment. Toroidal and poloidal viewing systems measure all quantities required to determine the radial electric field. Two sets of up/down symmetric poloidal views are used to measure both active emission in the plane of the neutral heating beams and background emission in a radial plane away from the neutral beams. Differential velocity measurements isolate the line-integrated poloidal velocity from apparent flows due to the energy-dependent chargeexchange cross section. Six f/1.8 spectrometers measure 276 spectra to obtain 75 active and 63 background channels every 10 ms. Local measurements from a similar midplane toroidal viewing system are mapped into two dimensions to allow the inversion of poloidal line-integrated measurements to obtain local poloidal velocity profiles. Radial resolution after inversion is 0.6-1.8 cm from the plasma edge to the center.