LIU Space Charge Studies for the LHC Pre-Accelerators

In 2011 a working group has been started to study performance limitations due to Space Charge (SC) in the four LHC pre-accelerators, LEIR, PSB, PS & SPS, in view of the LHC Injector Upgrade (LIU) project. To this end external and in-house simulation tools have been benchmarked for the LIU study cases with the long-term goal of providing a full sequence of tested CERN Space Charge tools. It became clear that SC studies must be combined with trustworthy models of the machines, including linear and non-linear errors. In particular an effective s-dependent non-linear model is required. Recent studies indicate that also the low frequency ripple spectrum due to conventional power supplies might play an important role for the beam dynamics in presence of space charge in the pre-injectors.