Ion optical stray field analysis of an ESR dipole

The ion optical characteristics of the injection into the ESR are calculated up to second order. The three dimensional model of an ESR dipole magnet forms the basis of our computations. Special efforts have been spent on an accurate approximation of the lateral stray field over a distance of 2 m, in which the ion beam enters the ESR dipole tangentially. The reference trajectory and the first and second order transformation coefficients are calculated solving the corresponding differential equations numerically. For this purpose we have developed a new ion optics section as part of the MAFIA postprocessing module P. The differential equations are set up and solved automatically using the simulated magnetic field distribution. The new implemented section is general and allows the easy calculation of beam trajectories and optical characteristics corresponding to arbitrary numerically calculated magnetic fields. As special feature also phase space monitors along a curved reference trajectory can be defined. We give a short introduction into the method and discuss the results in case of the ESR injection