Objective
The GSI linear accelerator UNILAC has to serve as a high current injector for the future GSI accelerator facility, especially for heavy ions like uranium. Presently the UNILAC is not able to provide for the required beam brilliance at the synchrotron injection. In the next future it is necessary to start with a R&D program in the different sections of the GSI linac: In order to increase the acceptance of the Radio Frequency Quadrupole (RFQ) section and thereby the particle transmission an upgrade of the RFQ is required. Additionally design studies for a high current; high acceptance RFQ accelerator for the GSI-Unilac has to be done to provide for the highest intensities for the IH-DTL. Also the LEBT-section has to be redesigned with respect to an increase of the particle number within the RFQ acceptance. At the synchrotron injection the beam brilliance has to be increased by optimising the focusing strength especially in the first Alvarez section. The impact of this measures to the gain in particle number and beam quality at the synchrotron injection has to be simulated. Further development of the multiparticle simulation codes should provide for useful simulation tools for the beam dynamics in the future GSI linear accelerator.