Relation between Hamada and Boozer Magnetic Coordinate System

摘要

The relation between the Hamada and the Boozer magnetic coordinate system isclarified by deriving them from a general magnetic field coordinate system. The coordinate transformation from the Hamada to the Boozer coordinate system is performed using a transformation function, which is easily calculated with the knowledge of the magnetic field strength only. In non-axisymmetric systems, the Fourier spectrum of the magnetic field strength (absolute value of B) in the Hamada coordinate system is broader than that in the Boozer coordinate system and the leading modes of (absolute value of B) in the Hamada coordinate system significantly deviate from a simple model field in comparison with the Boozer coordinate system. The Boozer coordinate system is suitable for numerical calculations, especially, for neoclassical and orbit calculations in non-axisymmetric systems.