Influence of the ATS Optics on Intra-Beam Scattering for HL-LHC

In the future High Luminosity (HL-)LHC the influence of intra-beam scattering (IBS) will be stronger than in the present LHC, because of higher bunch intensity, small emittance and new optics. The new ATS-optics scheme [1] modifies the lattice in the arcs around the main interaction points (IP) to provide β∗ values as small as 0.15m at the IP but these modifications affect the IBS growth rates. In this paper proton IBS emittance growth rates are calculated with MADX [2] and the Collider Time Evolution (CTE) program [3] for two ATS-optics versions, different settings of the crossing angles and required corrections and various beam conditions at injection (450 GeV) and collision (7 TeV) energy. CTE simulations of the expected luminosity, intensity, emittance and bunch length evolution during fills are also presented.