Some practical considerations involving spectral representations of 3-D plasma equilibria

Technical Report · Wed Apr 01 04:00:00 EST 1987

DOI:https://doi.org/10.2172/6566896· OSTI ID:6566896

Attenberger, S. E.; Houlberg, W. A.; Hirshman, S. P.

For describing magnetically confined toroidal plasmas, it is convenient in some instances to use a cylindrical coordinate system whose origin is on the major axis of the torus and in others to use a ''flux coordinate'' system bound to the magnetic flux which is embedded in the plasma. A good estimate of the flux surface geometry is available in spectral form in many cases, permitting a simple transformation from flux coordinates to cylindrical coordinates. A modified Newton iteration is described for performing the ''inverse'' transformation from cylindrical coordinates to flux coordinates. An accurate technique for radial spline interpolation of the spectral coefficients is given which is particularly useful for computing magnetic fields near the magnetic axis. Given a spectral representation of the plasma, it is possible to track a chord through the plasma, determining in sequence its intersections with a given set of flux surfaces. This technique is the starting point for many calculations, including neutral beam heating, pellet fueling, evaluation of absorption or plasma sources along the lines-of-sight of detectors, etc. An efficient algorithm for performing this calculation is given.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6566896
• Report Number(s): ORNL/TM-10412; ON: DE87010148
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700103* -- Fusion Energy-- Plasma Research-- Kinetics
ALGORITHMS
ANNULAR SPACE
CLOSED PLASMA DEVICES
COMPUTERIZED SIMULATION
CONFIGURATION
FORTRAN
ITERATIVE METHODS
MAGNETIC FIELDS
MAGNETIC FLUX
MATHEMATICAL LOGIC
MATHEMATICS
PLASMA
PLASMA DENSITY
PROGRAMMING LANGUAGES
SIMULATION
SPACE
SPECTRAL RESPONSE
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TOPOLOGY
TOROIDAL CONFIGURATION
TRANSFORMATIONS