Rapid Fourier space solution of linear partial integro-differential equations in toroidal magnetic confinement geometries
Fluctuating quantities in magnetic confinement geometries often inherit a strong anisotropy along the field lines. One technique for describing these structures is the use of a certain set of Fourier components on the tori of nested flux surfaces. We describe an implementation of this approach for solving partial differential equations, like Poisson's equation, where a different set of Fourier components may be chosen on each surface according to the changing safety factor profile. Allowing the resolved components to change to follow the anisotropy significantly reduces the total number of degrees of freedom in the description. This can permit large gains in computational performance. We describe, in particular, how this approach can be applied to rapidly solve the gyrokinetic Poisson equation in a particle code, ORB5 (Jolliet et al., (2007) ), with a regular (non-field-aligned) mesh.
Bibliographic Reference: An article published in: Computer Physics Communications, Article in Press, December 2009
Availability: This article can be accessed online by subscribers, and can be ordered online by non-subscribers, at: http://dx.doi.org/10.1016/j.cpc.2009.12.001
Record Number: 201010048 / Last updated on: 2010-01-13
Original language: en
Available languages: en