HL LHC WP3 (magnets) TASK 2 ADVANCEMENT CERN, 14th February 2012 WP3 – Task2 meeting HL LHC WP3 (magnets) TASK 2 ADVANCEMENT E. Todesco CERN, Geneva Switzerland With relevant inputs from colleagues L. Bottura, O. Bruning, R. De Maria, S. Fartoukh, P. Ferracin, P. Fessia, B. Holzer, L. Rossi, G. Sabbi, …

FOREWORD Task 2: Nb3Sn Triplet (G. Sabbi) Task 3: Separation dipoles (T. Nakamoto and P. Wanderer) Task 4: Cooling (R. Van Weldereen) Task 5: Other topics (J.-M. Rifflet) Q4 Nb-Ti triplet Resistive magnets around IR4 In these slides I focus on the triplet, which has the highest degree of coupling between different WP and aspects – top priority Meetings about other parts of the machine (D1, D2, Q4) will come soon Partecipation: meetings are open and contributions are welcome

APERTURE OF THE TRIPLET We can start analysing four lay outs given by WP2 Two technologies: Nb-Ti and Nb3Sn Two apertures: 120 mm (present hardware) and 140 mm (more performance ?) Aperture of D1 should be 10 mm larger than triplet Two cases being analysed: 130 mm and 150 mm (Task 3) First guess of four layouts up to D1 given by WP2 (S. Fartoukh, R. De Maria, B. Holzer)

PROOF OF TECHNOLOGY First priority is demonstrate Nb3Sn Nb-Ti is the plan B, that will be also discussed in the preliminary design report Independentely of 120/140 mm, the Nb3Sn technology will be proved on the ground of LARP on 120 mm HQ and LHQ magnets will prove the technology by 2014 This will require a full qualification Gradient, field quality, protection, heat transfer, …

THE PLAN Plan: have a first estimate of the performance in each case by June We should also provide time estimate for both 120 and 140 mm options, and rough estimate of costs If we go to 140 mm we will need more time We have to provide all the information to the project management in the first half of 2012 Decision on one aperture per Nb3Sn and one aperture for the Nb-Ti plan B in September 2012 Taken on the ground of performance, cost and schedule Decision on technology will be possible only in 2013-4

APERTURE OF THE TRIPLET We can start analysing four lay outs given by WP2 Two technologies: Nb-Ti and Nb3Sn Two apertures: 120 mm (present hardware) and 140 mm (more performance ?) Aperture of D1 should be 10 mm larger than triplet Two cases being analysed: 130 mm and 150 mm (Task 3)

THE CHOICE OF THE GRADIENT Gradient has been selected on the following criteria 20% operational margin on the loadline For Nb-Ti 120 mm: this is MQXC (15.1 mm LHC dipole cable, grading), gradient has been lowered to 118 T/m have 20% margin 140 mm: this is the sketch of MQXD cross-section presented by Glyn in November (15.1 mm LHC dipole cable, two layers) – 100 T/m For Nb3Sn 120 mm: this is HQ (MQXE) 0.8 mm Ø strand, 35 strands (~15 mm width) We lowered the jc at 12 T, 4.2 K from 3000 A/mm2 to 2600 A/mm2 We keep the same copper/non copper challenging ratio 1.13 This gives 170 T/m instead of 180 T/m as given previously 140 mm: this is MQXF [P. Ferracin] 0.8 mm Ø strand, 40 strands (~17 mm width - stress already top level in HQ) Same choice of jc and same copper/non copper ratio 1.13 This gives 150 T/m

MILESTONE OF JUNE - 1 June 2011: Make a first iteration between all different aspects to understand if some parameters are clearly not good for integration in the LHC First estimate of the powering scheme and magnet protection to understand if the copper content of the cable is too low Possible feedback on strand (very urgent) Have a first guess on maximum tolerable b6 at injection and compare to what obtained in HQ – have an idea of the FQ requirements on filament size Find the maximum size of cold mass given by integration and solve the problems related to fringe field Urgent for sizing of some tooling Explore the option of no beam screen, in collaboration with AT-VSC

MILESTONE OF JUNE - 2 Plan of studies up to June 2011 Have a first estimate of energy deposition from WP10 and necessary shielding Heat load versus margin Radiation resistance Heat load This will feedback on avaliable aperture and performance We should clarify the quench margin in continuous losses regime Can we apply a larger quench limit for enhanced insulation? More investigation for Nb3Sn limits This will allow WP2 to estimate the performance of the four lay-outs given the free aperture (June-August)

MILESTONES OF JUNE - 3 Analysis of MQXC and HQ field quality to provide field quality tables to WP2 This depends on conductor for some multipoles Estimation of the most dangerous multipoles and need of correctors This could feed back on the lay-out where some space for correctors is already allocated Have a first iteration on the interconnection lenghts with experts This also could feed back on lay out Analysis of tests of the existing hardware Analysis of HQ test (February 2012 at CERN) First test on MQXC (June 2012) Heat transfer aspects