1. R. Ostojic, IRP1 CD Review, 31 July 2008 LHC IR Upgrade Phase I Goals and Constraints 1.Upgrade goals and milestones 2.Upgrade of IR systems: main constraints 3.The proposed conceptual solution 4.Project status and collaborations 5.Expectations from the Review Acknowledgment to all participants of LIUWG meetings and to the speakers for their contributions and hard work.

2. The ATLAS and CMS interaction regions Dispersion suppressor Matching sectionSeparation dipoles Final focus Triplet position L* = 23 m Triplet gradient 205 T/m Triplet aperture Coil 70 mm Beam screen 60 mm   * = 0.55 m  L = 10 34 Power in triplet~ 200 W @ 1.9 K Q5D2/Q4TANQ2/Q3/D1

3. The low-  triplet in IR1/5 MQXAMQXBMQXAMQXB 6.375.5 6.37 MCBXAMCBXMQSX TASB MCBX Q3Q2Q1 MCSOX DFBX MBXW D1 QRL Triplets were designed and built by a collaboration of CERN, Fermilab, KEK, LBNL.  Two types of quads, MQXA (KEK) and MQXB (FNAL): identical aperture and operating gradient different operating current and inductance; nested powering all heaters fired for any quench condition; no energy extraction external HX  Nested correctors distributed in quadrupole cold-masses.  In-line feedbox providing all cryogenic, powering and instrumentation services.  Normal conducting D1 separation dipole (powered L+R in series).

4. The low-  triplet in IR1

5. The low-  triplet in IR5

6. The matching sections

7. LHC IR Upgrade - Phase I Goal of the upgrade: Enable focusing of the beams to  *=0.25 m in IP1 and IP5, and reliable operation of the LHC at 2-3 10 34 cm -2 s -1 on the horizon of the physics run in 2013. Scope of the Project: 1.Upgrade of ATLAS and CMS interaction regions. The interfaces between the LHC and the experiments remain unchanged. 2.The cryogenic cooling capacity and other infrastructure in IR1 and IR5 remain unchanged and will be used to the full potential. 3.Replace the present triplets with wide aperture quadrupoles based on the LHC dipole (Nb-Ti) cables cooled at 1.9 K. 4.Upgrade the D1 separation dipole, TAS and other beam-line equipment so as to be compatible with the inner triplets. 5.Modify matching sections (D2-Q4, Q5, Q6) to improve optics flexibility, and introduce other equipment to the extent of available resources.

8. Project milestones Project ApprovalDec 2007 Conceptual Design ReportJune 2008 Model quadrupoleend 2009 Technical Design Reportmid 2009 Pre-series quadrupoleend 2010 String test2012 Installationshutdown 2013

9. Main constraints (1) Interfaces with the experiments: Very tight interfaces between the triplet, TAS, shielding, vacuum and survey equipment, and beam instrumentation; no possibility of reducing L* (23m). Replacement of the TAS vacuum chamber requires removal of the TAS from the experimental caverns. Cryogenics: Replacement of triplets in IR1/5 requires at present warm-up of 4 sectors. The triplet in 5L may have less cooling capacity available than the others. Chromatic aberrations: Reduction of  * drives chromatic aberrations all around the LHC. A new optics solution for all arcs and insertions is necessary. Quench protection of the triplets: Due to considerably higher stored energy, energy extraction should be included.

10. Main constraints (2) Accessibility and maintenance: all electronics equipment around the triplets and the DFBX should be located in low radiation areas. Severe space constraints around IP1 and IP5 for any new equipment. Tunnel transport: access from the surface to IR1/5 requires that the overall dimensions of the vacuum vessels of the new magnets are similar to the LHC main dipole. Upgrade implementation: during the extended shutdown Nov 2012-June 2013, compatible with CERN-wide planning (Linac4 commissioning, upgrade of the experiments).

11. Proposed conceptual solution (1) LHC optics  Correction of chromatic aberrations in IR3, IR7 and in the inner triplets in IR1 and IR5 requires re-phasing of all the arcs and insertions for  * < 0.5 m. The strength of the arc sextupoles limits  * to 0.25 m.  Parasitic dispersion in the triplets due to large crossing angle has to be controlled and the beam crossing schemes in IP1 and IP5 need to be conform. A complete solution for the new LHC collision optics has been found. Considerable work is required to fully validate the flexibility and robustness of the solution.

12. Proposed conceptual solution (2) Low-  quadrupoles and IR optics  The flexibility of the IR optics and the aperture requirements in the matching sections depend on the gradient of the low-  quadrupoles, and can be improved if Q4, D2 and Q5 are moved by ~10-15 m towards the arc.  Solutions with gradients of 135, 125 and 115 T/m were examined, corresponding to coil apertures of 110, 120 and 130 mm. With LHC beam parameters and  *=0.25 m, effective apertures of n1=7, 8 and 9  are obtained in the triplet, satisfying the criteria for the nominal LHC of n1=7.  Only the solution with the highest gradient is compatible with the present position of the matching sections; lower gradients require moving Q4, D2 and Q5. The solution with a 115 T/m is at the limit of the DS-Q7 strength and Q5 aperture. The final choice of the magnet parameters is driven by the decision whether or not to move the matching section magnets.

13. Proposed conceptual solution (3) Triplet  Composed of four identical quadrupoles of about ~ 10 m.  Cold bore+beam-screen engineered as protection elements.  Interconnections identical in IR1 and IR5 designed according to ALARA principles.  Dipole and multipole correctors grouped in a separate cryo-unit located in between D1 and Q3.  All equipment designed for a lifetime of > 500 fb -1. Powering  Must allow flexibility for operation and different types of optics.  Energy extraction included to improve the protection redundancy and reduce the heat load to the 1.9 K level.  All delicate equipment located in low radiation areas with easy access. Identical feedboxes connected to the triplet with a SC link.

14. Proposed triplet layout As seen by the magnet builders (technical feasibility and costs),…, Iterations are expected. LHC triplet IRP1 triplet

15. Proposed powering scheme 1.9 K 4.5 K

16. Proposed equipment location in IP1 D1 cold Equipment location: - UJ14 base and 1st floor - UL - US15 SC link

17. Proposed equipment location in IP5 New rack layout symmetrical for each side Equipment location: -in the by-pass -add shielding in the UJs

18. Modifications in the matching sections Reduction of  * inevitably reduces the aperture margin in Q4, D2 and Q5 and nearby equipment.  Additional TCT collimators will be required.  TAN will have to be replaced.  Background will need special attention. In case of moving Q4, D2 and Q5, it would be reasonable at the same time to:  Modify the beam-screens in these magnets, and  Install the new TAN, and all other equipment that may profit from extensive modifications in these areas.

19. Issues for the Nb-Ti quad design Fixed parameters SC cable: LHC dipole cables Collar material:Nippon Steel YUS 130 (thickness 3 mm) Yoke material: Cockerill steel (thickness 5.8 mm) Cold mass outer diameter: 570 mm (iron yoke 550mm and shell thickness 10 mm). Issues Optimal use of available cable (width and length). Cable insulation scheme for improved heat transfer. Compatibility of materials with radiation levels. Design of the mechanical structure to support high forces. Collar and yoke transparency for improved coupling to the cold source. Integration of the heat exchanger.

20. Issues for the corrector design Fixed parameters … Cold mass outer diameter: 570 mm (iron yoke 550mm and shell thickness 10 mm). Issues In view of the radiation levels and mixed experience with impregnated coils, review and consider alternatives to using existing MCBX technology for the orbit dipoles.

21. Brief overview of the agenda Optics and layout options Beam crossing and alignment requirements Conceptual design of the new low-  quadrupole Design options for the correctors Energy deposition and radiation protection issues Cryogenic concept and options Powering and circuit protection Feedboxes and SC links Tunnel integration and planning aspects Not all issues covered in preparation of the conceptual design (priorities, resources …).

22. Issues not presented in the Review (1) Interfaces with the experiments  New TAS, interfaces with ATLAS and CMS vacuum chambers.  Forward detectors and luminosity calibration detectors in the LSS.  Background in the IRs. Vacuum system  Beam screens are required in cold magnets. Beam screen cooling at 5- 20K confirmed as cryogenically the most advantageous.  Replacement and/or alignment of warm vacuum chambers. Collimators in IR1 and IR5  Detailed study of TCT efficiency with the new optics. Triplet alignment system  Improvement of internal magnet metrology and support system; extension of existing local geodetic network system. Expected performance similar to the present system.

23. Issues not presented in the Review (2) Cryostats and interconnections  Design based on the LHC dipole cryostat; reuse or modify existing tooling.  Interconnection distance defined on the basis of LHC experience.  Detailed design and tooling must conform to the requirements of work in radiation areas. New TAN Magnet test programme Beam instrumentation Shielding … D1 dipole

24. Superconducting D1 magnet Several possibilities for D1: NC, SC and superferric magnets. A large aperture 4 T SC dipole is the most cost effective. RHIC DX magnet Coil aperture180 mm Cold bore163/174 mm Warm bore140 mm Magnetic length3.7 m Operating temp4.5 K Field4.4 T Current6.8 kA Stored energy1100kJ Inductance49 mH D1 = two DX in one cryostat

25. Possible layouts of D1 dipole Semi-stand alone D1: + integration with the triplet - special beam-screen Fully-stand alone D1: + integration with the tunnel + NEG-type vacuum chamber

26. Project structure (May 08) Removal of existing equipment and installation activities not yet included.

27. Cost estimate (Feb 08) Total: Materials: 48.5 MCHF (including production manpower) CERN manpower: 11.4 MCHF Elements of the project structure and cost estimates to be updated, and EVM to be setup after the Review.

28. Collaborations LHC IR Upgrade Phase I CERN EU-FP 7 SLHC-PP Special French contribution US-labs D1 separation dipole Cold powering Cryostat components Quadrupole components Production of the correctors Design and construction of the model quad Design of the correctors Design of the cryostats Quadrupole production Cryostating and testing Powering and protection

29. Status of collaborations (1) 1.CNI SLHC-PP – WP6 Collaboration between CERN-CEA-CNRS-STFC (RAL)-CIEMAT on the design and construction of the quadrupole model and prototype, and on the design and qualification of the correctors. 2.In-kind contribution from France CEA participates in the design and coil manufacture for the model quadrupole, procurement and follow-up of specific components for the series quadrupoles, and follow-up of correctors (all to CERN specification). CNRS participates in the design, procurement and follow-up of cryostat components and tooling. Collaborations started 1April 2008.

30. Status of collaborations (2) 3. Collaboration with the US-labs In view of the past contribution to the LHC construction and existing set of skills, CERN has invited the US-labs to contribute significantly to the Phase-I upgrade. After initial discussions, it is proposed that the US-labs should supply the D1 separation dipoles and all or part of the power feed-boxes. The existing US expertise in the domain of cryogenics, powering and quench protection should support these deliveries. These activities are aligned with U.S. long term goal of contributing to the Phase-II (Nb3Sn) quadrupoles and advanced accelerator technology. A proposal for funding presented to the US-DOE in June 2008.

31. Expectations from the Review The Review is first of all an opportunity to confirm, complete and correct the assumptions taken as basis of the present concept. The Review should give a recommendation for the basic parameters of the new low-  quadrupoles (gradient, aperture).  The choice of the quadrupole parameters is tightly linked with the decision to modify the matching section magnets, besides the triplets.  In both cases, the ultimate  * is the same and aperture targets are met. The difference is the additional aperture margin in the triplets (  n1~1  ) offered by modifications of the matching sections (magnets, TAN, TCT). Besides the performance and technical feasibility, the recommendation should take into account the availability of resources for completion of the technical design (2008-09), for equipment construction (2009-2012), and for installation during the 2013 shutdown, and recommend additional resources where necessary.