The HL-LHC luminosity goals pose various challenges that come from the increased radiation environment. Many magnets and equipments in the vicinity of the beam collision or beam service points will suffer from this increased radiation level, part from the debris and part from the primary beam: the energy deposition and the power must be carefully evaluated for proper functionality of the magnets (induced quench) and the damage/destruction limit must also be properly predicted. In addition, the cryogenic system capacity has to suit the total power absorbed by the cold masses, which scales proportionally to the peak luminosity as well. Moreover, dedicated protection devices (like the TAS and the TAN) and local shielding must sustain the induced thermomechanical stress. On the other hand, the 3000 fb-1 goal of integrated luminosity represents a quite demanding requirement in terms of lifetime of several components (superconducting cables, insulators, instrumentation, electronics, ...), defined by the dose and the radiation fluence to which materials are exposed.
In order to face such challenges, contributing to the machine design optimization and preventing critical showstoppers, radiation-matter interaction simulations, as accurate as possible, are essential, and imply the detailed modelling of the whole areas of interest as well as the proper characterization of the relevant source terms, including beam losses in addition to beam-beam collisions. The energy deposition studies will feed into almost all working packages: WP1 (for safety: use of the same modelling and type of calculation), WP2 (for optics and positioning of various elements), WP3 (for magnets stability and protection), WP5 (the energy deposition by beam losses are part of the design of the collimators themselves, see task 5.3), WP6 (Stability and protection of the sc link, part of task 6.3 given the important implication on its design), WP11 (11 T dipole for dispersion suppressor); WP12 (Integration).