[en] A study is presented of the dispersion of the inductions in a given magnet, mechanically perfect, but having large dispersion among its regions (due to the fractioning of the magnets), for the GANIL heavy ion accelerator. This study was carried out with the computer program POISSON, used in rotational symmetry. With this program it is possible to divide the magnetic circuit into several regions corresponding to different steels. Only certain divisions can be studied, since the program is two-dimensional. It should be noted that this study can be divided into two parts. One part relates to the division of the flux-return yokes, and the other part deals with the pole pieces. The steels used in the yokes correspond to the two extreme curves already shown in a previous report. The steels used in the pole pieces correspond to the two extreme curves of a forged steel of good quality