The elements related to the injection and extraction of the beams need to be reviewed as part of the HL-LHC project. Some of the elements will need to be upgraded or replaced to adapt to the increased beam brightness and/or intensity.
The LIU-SPS project is responsible for the LHC transfer lines up to the entrance of the injection septa MSI. From the MSI onwards, all LHC beam transfer systems are covered by WP14.
The injection absorber TDI will need to be replaced to be able to absorb a full injection of 288 bunches with LIU maximum beam parameters in case of an injection kicker failure. The total absorption length of the TDI will need to be increased. Beam impact and material studies are required to determine the new absorber. Special care needs to be taken to minimize the beam impedance in the protection and parking positions. Beam impact simulations need also to be made for the auxiliary absorbers TCLIA, TCLIB and the protection masks TCLIM and TCDD to determine whether these systems need to be adapted.
An upgrade of the LHC injection kickers MKI is already underway. It consists of beam impedance reduction, cooling and cleaning measures. Further studies are required, taking into account theoretical and operational data, to ensure that the beam induced heating of the kicker ferrites will not reduce the machine availability, for the HL-LHC parameters.
Combinations of injection kicker and injection protection failures can lead to significant machine damage. Injection protection studies will need to be updated as part of the kicker, TDI and TCLI studies, and also as part of any proposed change of operational configuration which might affect the protection or the machine aperture.
The compatibility of the LHC beam dumping system with the increased beam intensities of the HL-LHC beams needs also to be studied. Of particular concern are the dump protection devices TCDQ, TCSG and TCDQM, and the positioning of the mobile jaws close to the beam. The impact of the HL-LHC beams on the dump absorber block TDE, the dump line, the dump block entrance window and the dump BTV screens require further simulation studies and possibly hardware modifications. Studies of the dump absorber block TDE include the dilution pattern and results of the studies might affect the parameters of the dilution kicker magnets MKB.
It has to be verified that any changes in optics or beam trajectories in the injection and beam dump regions is compatible with the operational range of the injection and beam dump elements and the related absorbers. It also needs to be verified that in case of any changes the injection and dumping protection and efficiency are not affected. Both tasks require a close collaboration with WP2.