An inversion technique to obtain full poloidal velocity profiles in a tokamak plasma
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543-0451 (United States)
An inversion technique has been developed to calculate local poloidal rotation velocities of impurity ions from line-integrated measurements of an extended emission source in a tokamak plasma. This technique can recover radial spatial resolution that is lost due to the curvature of the field lines. With charge exchange emission from neutral beams, it can be used to obtain poloidal velocity profiles across the entire minor radius of the plasma without requiring restricted neutral beam height to localize the emission. The technique consists of two Abel-like matrix inversions to obtain the emissivity and the velocity-weighted emissivity from which the velocity is obtained. Use of the neutral beams breaks the assumed symmetry, but knowledge of the beam deposition and geometry allow analogous matrices to be generated. The inversion technique is demonstrated with a simulation of a poloidal rotation diagnostic for the TFTR tokamak with tangential neutral beams with a height of 80 cm. Two opposing vertical views are required to handle effects of the charge exchange cross section, which can cause apparent velocities greatly in excess of expected poloidal velocities. The simulated errors due to the inversion process are about 1.5 km/s near the plasma center. {copyright} {ital 1997 American Institute of Physics.}
- Research Organization:
- Princeton Plasma Physics Laboratory
- DOE Contract Number:
- AC02-76CH03073
- OSTI ID:
- 452849
- Report Number(s):
- CONF-960543--
- Journal Information:
- Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 2 Vol. 68; ISSN 0034-6748; ISSN RSINAK
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ATOMIC BEAMS
BEAM-PLASMA SYSTEMS
CALIBRATION
CHARGE EXCHANGE
CROSS SECTIONS
EMISSIVITY
ERRORS
FIBER OPTICS
GEOMETRY
OPTICAL SYSTEMS
PLASMA DIAGNOSTICS
PLASMA IMPURITIES
PLASMA SIMULATION
RELATIVISTIC PLASMA
RESOLUTION
ROTATION
SPATIAL DISTRIBUTION
TFTR TOKAMAK
TOKAMAK DEVICES
VELOCITY
plasma collision processes
plasma toroidal confinement
plasma-beam interactions