The Development of Calculation Methods for Complex Magnetic Systems

In contrast to some programs, intended for modeling 2D magnetic elds, widely known commercial 3D CAD programs do not have special routines for users to control the accuracy of computations to a full degree. It does not permit to estimate with sucient condence the magnitude of magnetic elds in regions where the magnitude is comparable with approximation error of the nite element method used in calculations. An example of this situation is a problem of estimating the mutual inuence of magnetic elds in the magnetic systems of experiments ALICE (CERN, Geneva), PANDA (GSI, Darmshtadt) consisting of solenoid and dipole magnets. Another example is a problem to estimate the magnitude of magnetic eld in the region of beam channel protected against the dipole eld of a spectrometer. The paper [1] presents an algorithm for construction of spectrometer dipole computer models with quality control. Fig. 1 shows a computer model elaborated by the authors for the PANDA experiment. The peculiarity of the model is an iron plate in the median plane of the dipole for shielding a beam against magnetic eld. The radius of the beam channel inside the plate is 3.5 % of the distance between poles of the magnet. Fig. 2 give