Possible scenarios for the LHC injector upgrade

The possible upgrade of the LHC injector chain is a crucial step towards the LHC luminosity upgrade beyond 1034 cm-2s-1. It is also a mandatory requirement for the LHC energy upgrade well beyond the ultimate value of 7.56 TeV per beam. By pushing the accelerator parameters to the ultimate performance we can increase to 1.7×1011 the bunch population and eventually reach a peak luminosity of 2.3×1034 cm-2s-1. To go beyond, a considerable improvement of the LHC parameters, such as ß*, beam intensity, bunch length, number of circulating bunches is required. Finally, the upgrade of the injector complex and of the injection energy is another important ingredient to upgrade both peak and integrated luminosity up to an order of magnitude above the nominal value.