Computing 3D magnetic fields from insertion devices

A 3D magnetostatics computer code optimized for Undulators and Wigglers is described. The code uses a boundary integral method and makes extensive use of analytical expressions for the field and field integrals along a straight line. The code outperforms currently available finite element packages in the area of simple data input, CPU time of the solver and accuracy reached for the estimation of field integrals. It is written in C++ and takes advantage of object-oriented programming. The code is interfaced to Mathematica. Pre- and post-processing of the field data is done in the Mathematica Language. It has been extensively benchmarked with respect to a commercial finite element code. All ESRF Insertion Devices built during the last 4 years have been designed using this code or an older version