Use of Simulations Based on Experimental Data

Compared to the simulation of classical high perveance extraction systems for high current ion sources, the extraction of typical ECRIS is more complicated because more parameters, partially unknown, are involved. To reduce the computational effort, it would be helpful to determine several of these unknown parameters affecting mainly the starting conditions for trajectories in space and in momentum. The influence of the magnetic field on the beam in the extraction region is studied. Here the magnetic flux density distribution is fixed, but the starting conditions of all particles can be modified within reasonable limits in the simulation to investigate this influence.The GSI CAPRICE ECRIS was equipped with a movable accel-decel extraction system in order to investigate the influence of electric field gradient and space charge compensation as well as further effects of ion extraction. First results will be presented and will be compared with computer simulations. For the most simple case of Helium operation, simulation shows good agreement with experimental results, indicating the correctness of the applied model