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CERN, 11 th 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, ….
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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 recombinationdipoles[T. Nakamoto KEK , P. Wanderer BNL] • Task 4. Cooling[ R. van Weldeeren, CERN] • Task 5. Othertopics[J. M. Rifflet, CEA] • Large aperture Q4 • Nb-Ti option for the inner triplet • Resistivequadrupoles in IR3 and IR7
LAY-OUT FOR THE LUMINOSITY UPGRADE • Issue: different workpackages need info from others, creating loops • Green: beamdynamics WP2 • Blue: magnet WP3 • Red: energydeposition WP3 • Yellow: powering WP3 Protection Length Coil aperture Magnet design: Gradient, Current, Yoke Storedenergy Cooling Lay-out Beam aperture Powering Field quality Heatload, Shielding Correctors Crossing angle Beta* Beamscreen & cold bore
LAY-OUT FOR THE LUMINOSITY UPGRADE • Issue: different workpackages need info from others, creating loops • Green: beamdynamics WP2 • Blue: magnet WP3 • Red: energydeposition WP3 • Yellow: powering WP3 Protection Length Coil aperture Magnet design: Gradient, Current, Yoke Storedenergy Cooling Lay-out Beam aperture Powering Field quality Heatload, Shielding Correctors Crossing angle Beta* Beamscreen & cold bore
LAY-OUT FOR THE LUMINOSITY UPGRADE • Issue: different workpackages need info from others, creating loops • Green: beamdynamics WP2 • Blue: magnet WP3 • Red: energydeposition WP3 • Yellow: powering WP3 Protection Length Coil aperture Magnet design: Gradient, Current, Yoke Storedenergy Cooling Lay-out Beam aperture Powering Field quality Heatload, Shielding Correctors Crossing angle Beta* Beamscreen & cold bore
LAY-OUT FOR THE LUMINOSITY UPGRADE • Issue: different workpackages need info from others, creating loops • Green: beamdynamics WP2 • Blue: magnet WP3 • Red: energydeposition • Yellow: powering Protection Length Coil aperture Magnet design: Gradient, Current, Yoke Storedenergy Cooling Lay-out Beam aperture Powering Field quality Heatload, Shielding Correctors Crossing angle Beta* Beamscreen & cold bore
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 • Coolingshoulditeratewithmagnet design • Field quality and need of correctors mayiteratewithlay out • A first sketch should be available as soon as possible (end of the year) • Many WP justneed an estimate, not the final numbers • But theycannotwait for final design otherwiseistoolate …
MAGNETS FOR THE INNER TRIPLET • Todaywe have twopieces of hardware at 120 mm • MQXC – 120 mm aperture Nb-Ti quadrupole (ex-phase I) • Coilfabricated - short model beingassembled • Test for spring 2012 • HQ – 120 mm aperture Nb3Sn quadrupole (LARP) • Magnetassembled and tested ta 4.2 K a few times • Second set of coilsbeingassembled • To betestedalsoat CERN • I would call this MQXD
MAGNETS FOR THE INNER TRIPLET • Indication frombeamdynamics: • Larger apertures cangivelarger performance • Drawbacks withlarger apertures: • Longer & largermagnets, largerstoredenergy, difficult protection • Largerfringefield • Longer times for new design and tooling (2 years?) • Wewillstudy140 mm aperture cases • MQXE – 140 mm aperture Nb-Ti quadrupole • MQXF – 140 mm aperture Nb3Sn quadrupole • In summer 2012 wewill have • Evaluation of gain in performance from 120 to 140 mm • Understand if 140 mm is possible • Management willdecide
MQXF – CONCEPTUAL design • Inputs: Nb3Sn 140 mm aperture and 20% margin • Options [see P. Ferracin talk] • Cablewidth: 15 mm as in HQ or 17 mm to reduce stress • Timeline for first sketch of conceptual design: 1.2012 • Outputs (report) • Operationalcurrent, gradient • Stresses, conceptualmechanicalstructure • Choice of the cable • Field maps, coil cross-section, fieldquality • Used by • Energydeposition (fieldmaps) • Protection and powering (cable, current, storedenergy, inductance) • Cooling (margin, cross-section) • Optics (lay-out, fieldquality)
MQXE – CONCEPTUAL design • Inputs: Nb-Ti 140 mm aperture, 20% margin • Options[see G. Kirby talk] • LHC dipolecable (graded or not?) • Timeline for first sketch of conceptual design: 1.2012 • Outputs (report) • Operationalcurrent, gradient • Stress, conceptualmechanical structure as in MQXC • Field map, coil cross-section, fieldquality • Used by • Energydeposition (fieldmaps) • Protection and powering (cable, current, storedenergy, inductance) • Cooling (margin, cross-section) • Optics (lay-out, fieldquality)
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 increasedfrom 120 T/m (2008) up to 127 T/m • Now the loadlinemarginis 11%, temperaturemarginonly of 1.2 K • We propose to go back 20% margin, lower gradient Timeline: 1.2012 • Outputs (web) • New operationalcurrent, gradients, margins, fieldmap • Used by • Energydeposition (fieldmaps) • Protection and powering (cablefeatures, current, storedenergy, inductance) • Cooling (margin, cross-section) • Optics (lay-out, fieldquality)
MBXD/E – CONCEPTUAL design MBXD/E: wide & single aperture, Nb-Ti separationdipole [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) • Operationalcurrent, gradient (both options) • Stress, conceptualmechanical structure (both options) • Choice of the cable - Field map, cross-section • Used by • Energydeposition (fieldmaps) • Protection (cablefeatures, current, storedenergy, inductance) • Cooling (margin, cross-section) - Optics
LAY OUTS Definition of four lay-outs • 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 (frommagnet design) • Hypothesis on correctors, and interconnectionlengths • Timeline: January 2012 • Outputs (web) • Magnetlengths • Used by • Energydeposition (lay-outs) • Protection and powering (total storedenergyand inductance)
PROTECTION • Inputs • Operationalfields and gradients • Cableproperties • Magnetlengths • Options • Heaters, dump resistors, poweringscheme • Timeline: fromJanuary 2012 to December 2012 • Outputs (report) • First proposal of protection for the twolay outs • Identifybottlenecksthatcouldmake one lay out impossible • Used by • Magnet design (iteration on copper/no copper ratio in cable)
COOLING • Design of the yokeshouldincludefrom the beginningcoolingrequirements (as for MQXC) • Inputs • Magnet cross-section • Heatloads • Temperaturemargins • Options • 1.9 or 4.2 K • Timeline: fromJanuary 2012 to December 2012 • Outputs (report) • Coolingscheme • Structure of the iron • Used by • Magnet design (iteration on ironand/or margin if needed)
OPEN ISSUES TO BE CLARIFIED SOON • Limit in the energydeposition: • 4.3 mW/cm3used for Nb-Ti, based on veryoldestimates • Reviewthislimit and understand how much set for Nb3Sn • Maximal fringefield acceptable in the tunnel • Withlarger apertures wewill have 10-100 mT on the cryostat • Cold mass size limited • Shieldingneeded? • Radiation resistance of all materials • Weneed 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 decisionat the end of the study