High current beam dynamics for the upgraded UNILAC

The performance of the UNILAC as a high current, heavy ion injector into the SIS has been investigated including the future RFQ-IH-type pre-stripper accelerator. The beam dynamics are influenced by space charge forces in all sections of the accelerator, most severely after the the strippers at 1.4 MeV/u and 11.4 MeV/u. In previous studies a strong dependence of emittance growth on the initial intensity distribution and the envelope forming of the beam had been found. In order to obtain reliable beam parameters and to determine the consequences for the injection into the SIS, the beam behaviour was simulated through the complete system down to the SIS starting with Gaussian particle distributions after the ion source.