1. The HiLumi LHC Design Study is included in the High Luminosity LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. Chamonix Summary of Session 6 on the HL-LHC upgrade Organized by O. Brüning and Paolo Ferracin together with all the speakers Summary of Session 6 on the HL-LHC

2. 2 Session Overview: The Session featured 6 presentations with 20min presentation and 10 min of discussion for each presentation: HL-LHC Parameter and Lay-out Baseline  Paolo Fessia HL-LHC Magnet Roadmap  Ezio Todesco HL-LHC RF Roadmap  Rama Calaga HL-LHC alternative scenarios, parameters and lay-out  Rogelio Tomas Collimation and MP Roadmap  Stefano Redaelli Down Selection Criteria and MDs Prior to LS3  Gianluigi Arduini Summary of Session 6 on the HL-LHC

3. Equipment on the BeamTunnel equipment Vert. J Surface Eq.Dis. DF(X-M) + SC Link DSH (X-M) Cryo line Alignment QPS2 Magnet system MQXFA MQXFB, MBXF, MBRD, MQYY, Q5 1.9, Q6 1.9 MCBXFB, MCBXFA, MQSXF, MCTXF, MCTSXF, MCDXF, MCDSXF, MCOXF, MCOSXF, MCSXF,MCSSXF, MCBRD, MCBYY Beam vacuum TAXS, TAXN Interaction Region and MSIP 1,5 Collimation (TCTPM, TCL, TCLM, TCTP) Beam diagnostic BPMSQW, BMPSQ, BPMSQT, BMLC DS Collimation for ionIP 2 H.F. dipoles Cryo-bypass+TCLD DFH(X-M) + Power converters EE Crab Cavity cryomodules RF system Loads, circulators, RF power, LLRF, HVPS, central LLRR (TBC RUN II) DS Collimation pp (TBC RUN II) IP 1,5 H.F. dipoles Cryo-bypass+TCLD (TBC RUN II) DS Collimation pp (TBC RUN II) IP 7 H.F. dipoles Cryo-bypass+TCLD Rad-hard electronics for BLM and BPM CC diagnostic and protection PICPIC BISBIS DFA+ SC Link DSHA DFHA + Power converters SC link/ Powering arc IP 1,5 CryoplantIP 1,5 CB Warm compressor and other surface eq. SC link/poweringIP 7 Hor. SC L. DSH + DFA Power converters New DSLM for Q6 Summary of Session 6 on the HL-LHC Talk 1: Paolo Fessia

4. CS Baseline collection completed each system/equipment with Conceptual Spec, presently 90 document recorded 4 Courtesy of I. Bejar Alonso, S. Chemli Summary of Session 6 on the HL-LHC Talk 1: Paolo Fessia

5. E. Todesco HL LHC magnets roadmap - 5 LAY OUT Last bits being frozen (correctors for D2 Q4) 2008 2022 Summary of Session 6 on the HL-LHC Talk 2: Ezio Todesco

6. E. Todesco WP3 status - 6 CONTENTS: HL-LHC IR MAGNETS Triplet QXF (LARP and CERN) Separation dipole D1 (KEK) Recombination dipole D2 (INFN design) Q4 (CEA) Skew corrector (INFN) Corrector sextupole (INFN) Corrector dodecapole (INFN) Corrector octupole (INFN) Corrector decapole (INFN) Orbit corrector (CIEMAT) Cross-sections in scale Summary of Session 6 on the HL-LHC Talk 2: Ezio Todesco

7. E. Todesco HL LHC magnets roadmap - 7 11 TESLA: IDEA Idea: replace a 8.3 T Nb-Ti dipole with 11 T Nb 3 Sn dipole This leaves enough space for a 0.8 m long room temperature collimator One dipole replaced by two 5.5-m-long dipoles plus r.t. collimator 4 units needed for IP2 in LS2 – first Nb 3 Sn seeing a beam! 8 units needed for IP7 in LS3 Up to 16 more units could be needed at IP5 and IP1 in LS3 Summary of Session 6 on the HL-LHC Talk 2: Ezio Todesco [Baseline program of WP5 for Col Upgrade]

8. 8 [Studies for ‘Option 0’ of Crab Kissing scheme ongoing] Summary of Session 6 on the HL-LHC Talk 3: Rama Calaga  Required for longit. bunch shaping

9. 9 Summary of Session 6 on the HL-LHC Talk 4: Rogelio Tomas

10. 10 Summary of Session 6 on the HL-LHC Talk 4: Rogelio Tomas

11. 11 Summary of Session 6 on the HL-LHC Talk 5: Stefano Redaelli MoGraphite DS Collimators E-lens & altern

12. 12 Summary of Session 6 on the HL-LHC Talk 5: Stefano Redaelli

13. 13 Nominal Scenario: Areas for MD studies during RunII Some of the challenges: Low  * optics with well behaved chromatic properties Electron cloud effects with 25 ns beams Large crossing angle and Crab Crossing to minimize the geometric reduction factor and pile-up density (SPS tests)  * levelling Large beam-beam tune spreads Beam Halo Measurement and Control particularly to cope with possible crab cavities failure scenarios. Stability and Minimization of impedance  Collide & Squeeze Dynamic Aperture Flat Optics Summary of Session 6 on the HL-LHC Talk 6: Gianluigi Arduini

14. 14 Main Points from the Q&A sessions: It is important to quantify the required availability and efficiency for reaching HL- LHC performance and to check these for all LHC systems (high reliability machine!) Stochastic Cooling (for Ion operation) is not in the HL-LHC Baseline Need for prioritization of MS upgrades not yet in the baseline (e.g. new Q5 in IR1 & 5) and identification of resulting performance limitations. Need for clarification of ‘ultimate’ HL-LHC performance. Issue of small series production and risk mitigation (multiple producers). Need for clarification of spare RF components for new HL-LHC equipment. Interplay of 200MHz LH RF system and 400MHz Crab-Cavities (non-linearity). Are there plans for testing Crab Cavities in the LHC after the SPS tests and before HL-LHC?  Have been looked at at IP4 but would have impact on schedule! Preferred luminosity levelling method  dynamic low-beta and NOT Crab cavities Summary of Session 6 on the HL-LHC

15. The HiLumi LHC Design Study is included in the High Luminosity LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. 15 Summary of Session 6 on the HL-LHC