Hamiltonian Guiding Center Equations in Toroidal Magnetic Configurations
Authors: Roscoe White and Leonid Zakharov
Date of PPPL Report: September 2002
Published in: Physics of Plasmas 10 Issue 3, 573-576
Guiding center equations for particle motion in a general toroidal magnetic equilibrium configuration are derived using magnetic coordinates. Previous derivations made use of Boozer coordinates, in which the poloidal and toroidal angle variables are chosen so that the Jacobian is inversely proportional to the square of the magnetic field. It is shown that the equations for guiding center motion in any equilibrium possessing nested flux surfaces have exactly the same simple form as those derived in this special case. This allows the use of more spatially uniform coordinates instead of the Boozer coordinates, greatly increasing the accuracy of calculations in large beta and strongly shaped equilibria.