3-D magnetic calculation methods for spiral scaling FFAG magnet design

2-D and 3-D magnetic calculation tools and methods have been developed at SIGMAPHI, in collaboration with IN2P3/LPSC, to design spiral FFAG (fixed field alternating gradient) magnets. These tools are currently being used for RACCAM spiral scaling FFAG magnet design. In the particular case of a spiral gap shaped magnet, a careful magnetic design has to be realized in order to keep both vertical and horizontal tunes constant during acceleration process. Promising results, obtained from tracking in 3-D field maps, demonstrate the efficiency of the horizontal and vertical tune adjustment methods presented in this paper.