Code Requirements for Long Term Tracking with Space Charge

In view of the LHC Injectors Upgrade (LIU) for the LHC pre-accelerators Leir, PSB, PS, SPS we have started a new working group at CERN to deal with space charge issues of these machines. The goal is to operate these machines with basically twice the number of particles per bunch which will further increase the space charge tune shifts which are large already now in present operation. Besides the obvious remedies of increasing the injection energy we are obliged to better understand the space charge force to optimize our machines. To this end it has become clear that we need computer models that faithfully represent the linear but also the non-linear features of our machines. We have started close collaborations with several laboratories around the world to upgrade existing self-consistent Space Charge Particle-In-Cell (PIC) codes for our CERN needs. In parallel, we have created a frozen space charge facility in CERN's MAD-X code. Both types of codes are being used to study long-term stability of our machines and to compare it with machine experiments.