CERN, 11th November 2011 Hi-lumi meeting HL-LHC: INITIAL WORKFLOW BETWEEN MAGNETS, BEAM DYNAMICS, AND ENERGY DEPOSITION E. Todesco CERN, Geneva Switzerland With relevant inputs from colleagues M. Bajko, A. Ballarino, O. Bruning, R. De Maria, F. Cerutti, L. Rossi, …

TASKS OF THE WORKPACKAGE Task 2. IR quadrupoles in Nb3Sn [G. L. Sabbi , LBNL] Task 3. Separation and recombination dipoles [T. Nakamoto KEK , P. Wanderer BNL] Task 4. Cooling [ R. van Weldeeren, CERN] Task 5. Other topics [J. M. Rifflet, CEA] Large aperture Q4 Nb-Ti option for the inner triplet Resistive quadrupoles in IR3 and IR7

LAY-OUT FOR THE LUMINOSITY UPGRADE Issue: different workpackages need info from others, creating loops Green: beam dynamics WP2 Blue: magnet WP3 Red: energy deposition WP3 Yellow: powering WP3 Length Protection Coil aperture Magnet design: Gradient, Current, Yoke Stored energy Cooling Lay-out Beam aperture Powering Field quality Heat load, Shielding Correctors Crossing angle Beam screen & cold bore Beta*

LAY-OUT FOR THE LUMINOSITY UPGRADE Issue: different workpackages need info from others, creating loops Green: beam dynamics WP2 Blue: magnet WP3 Red: energy deposition WP3 Yellow: powering WP3 Length Protection Coil aperture Magnet design: Gradient, Current, Yoke Stored energy Cooling Lay-out Beam aperture Powering Field quality Heat load, Shielding Correctors Crossing angle Beam screen & cold bore Beta*

LAY-OUT FOR THE LUMINOSITY UPGRADE Issue: different workpackages need info from others, creating loops Green: beam dynamics WP2 Blue: magnet WP3 Red: energy deposition WP3 Yellow: powering WP3 Length Protection Coil aperture Magnet design: Gradient, Current, Yoke Stored energy Cooling Lay-out Beam aperture Powering Field quality Heat load, Shielding Correctors Crossing angle Beam screen & cold bore Beta*

LAY-OUT FOR THE LUMINOSITY UPGRADE Issue: different workpackages need info from others, creating loops Green: beam dynamics WP2 Blue: magnet WP3 Red: energy deposition Yellow: powering Length Protection Coil aperture Magnet design: Gradient, Current, Yoke Stored energy Cooling Lay-out Beam aperture Powering Field quality Heat load, Shielding Correctors Crossing angle Beam screen & cold bore Beta*

LAY-OUT FOR THE LUMINOSITY UPGRADE We have to cut the loop Proposal: we start from coil aperture, and then we estimate performance Iteration of the loop may be necessary Crossing angle input and output Cooling should iterate with magnet design Field quality and need of correctors may iterate with lay out A first sketch should be available as soon as possible (end of the year) Many WP just need an estimate, not the final numbers But they cannot wait for final design otherwise is too late …

MAGNETS FOR THE INNER TRIPLET Today we have two pieces of hardware at 120 mm MQXC – 120 mm aperture Nb-Ti quadrupole (ex-phase I) Coil fabricated - short model being assembled Test for spring 2012 HQ – 120 mm aperture Nb3Sn quadrupole (LARP) Magnet assembled and tested ta 4.2 K a few times Second set of coils being assembled To be tested also at CERN I would call this MQXD

MAGNETS FOR THE INNER TRIPLET Indication from beam dynamics: Larger apertures can give larger performance Drawbacks with larger apertures: Longer & larger magnets, larger stored energy, difficult protection Larger fringe field Longer times for new design and tooling (2 years?) We will study 140 mm aperture cases MQXE – 140 mm aperture Nb-Ti quadrupole MQXF – 140 mm aperture Nb3Sn quadrupole In summer 2012 we will have Evaluation of gain in performance from 120 to 140 mm Understand if 140 mm is possible Management will decide

MQXF – CONCEPTUAL design Inputs: Nb3Sn 140 mm aperture and 20% margin Options [see P. Ferracin talk] Cable width: 15 mm as in HQ or 17 mm to reduce stress Timeline for first sketch of conceptual design: 1.2012 Outputs (report) Operational current, gradient Stresses, conceptual mechanical structure Choice of the cable Field maps, coil cross-section, field quality Used by Energy deposition (field maps) Protection and powering (cable, current, stored energy, inductance) Cooling (margin, cross-section) Optics (lay-out, field quality)

MQXE – CONCEPTUAL design Inputs: Nb-Ti 140 mm aperture, 20% margin Options [see G. Kirby talk] LHC dipole cable (graded or not?) Timeline for first sketch of conceptual design: 1.2012 Outputs (report) Operational current, gradient Stress, conceptual mechanical structure as in MQXC Field map, coil cross-section, field quality Used by Energy deposition (field maps) Protection and powering (cable, current, stored energy, inductance) Cooling (margin, cross-section) Optics (lay-out, field quality)

MQXC FOR 5×1034 cm-2 s-1, 3000 fb-1 Born in the Phase I upgrade framework 2.5×1034 cm-2 s-1, 700 fb-1  5×1034 cm-2 s-1, 3000 fb-1 Gradient increased from 120 T/m (2008) up to 127 T/m Now the loadline margin is 11%, temperature margin only of 1.2 K We propose to go back 20% margin, lower gradient Timeline: 1.2012 Outputs (web) New operational current, gradients, margins, field map Used by Energy deposition (field maps) Protection and powering (cable features, current, stored energy, inductance) Cooling (margin, cross-section) Optics (lay-out, field quality)

MBXD/E – CONCEPTUAL design MBXD/E: wide & single aperture, Nb-Ti separation dipole [see T. Nakamoto talk] Inputs: 130 mm and 150 mm apertures – 30% margin Options LHC (30 mm) or MQXA cables (20 mm) Timeline: 1.2012 Outputs (report) Operational current, gradient (both options) Stress, conceptual mechanical structure (both options) Choice of the cable - Field map, cross-section Used by Energy deposition (field maps) Protection (cable features, current, stored energy, inductance) Cooling (margin, cross-section) - Optics

LAY OUTS Definition of four lay-outs Inputs Timeline: January 2012 120 mm quad (Nb3Sn MWXD or Nb-Ti MQXC) plus 130 mm MBXD 140 mm quad (Nb3Sn MWXF or Nb-Ti MQXE) plus 150 mm MBXE Inputs Gradients (from magnet design) Hypothesis on correctors, and interconnection lengths Timeline: January 2012 Outputs (web) Magnet lengths Used by Energy deposition (lay-outs) Protection and powering (total stored energy and inductance)

PROTECTION Inputs Options Timeline: from January 2012 to December 2012 Operational fields and gradients Cable properties Magnet lengths Options Heaters, dump resistors, powering scheme Timeline: from January 2012 to December 2012 Outputs (report) First proposal of protection for the two lay outs Identify bottlenecks that could make one lay out impossible Used by Magnet design (iteration on copper/no copper ratio in cable)

COOLING Design of the yoke should include from the beginning cooling requirements (as for MQXC) Inputs Magnet cross-section Heat loads Temperature margins Options 1.9 or 4.2 K Timeline: from January 2012 to December 2012 Outputs (report) Cooling scheme Structure of the iron Used by Magnet design (iteration on iron and/or margin if needed)

OPEN ISSUES TO BE CLARIFIED SOON Limit in the energy deposition: 4.3 mW/cm3 used for Nb-Ti, based on very old estimates Review this limit and understand how much set for Nb3Sn Maximal fringe field acceptable in the tunnel With larger apertures we will have 10-100 mT on the cryostat Cold mass size limited Shielding needed? Radiation resistance of all materials We need to launch tests for 100-150 MGy

TENTATIVE SCHEDULE FOR NEXT 12 MONTHS Tentative date: have in August 2012 a decision on 120/140 mm Hypotheses on technology: Nb3Sn is the baseline, Nb-Ti the plan B Final decision at the end of the study