HiLumi-LHC / LARP Conductor and Cable Internal Review October 16 th and 17 th 2013 H. Felice LARP Short Magnets Fabrication and Test experience relevant to QXF conductor and cable specifications

What is a successful magnet? A magnet in which every single stage of fabrication has been successful A magnet will be considered successful when I quench > 90 % Iss 10/17/20132 LARP history illustrates the involvement of each of these steps in magnet success and failures… H. Felice Cable Coil Fabrication Assembly - Preload StrandDesign

Successful LARP Magnets 10/17/20133H. Felice Large parameter space covered by short models

From TQS02 series to TQS03 series TQS02c High RRR (>200) 70 microns filament 47 % Cu fraction Jc (12T, 4.3 K) 2925 A/mm 2 Tested at CERN TQS03 High RRR (>200) 50 microns filament 54 % Cu fraction Jc (12T, 4.3 K) 2770 A/mm 2 Tested at CERN 205 – 210 T/m 220T/m Moving from 54/61 to 108/127 improved performances at 1.9 K In TQ 10/17/2013H. Felice4 220 T/m 238 T/m

TQS03 series and stress limit With Lorentz forces at 12 kA 10/17/ tests: TQS03 a, b, c and d performed with variable pre-stress TQS03a: 120 MPa TQS03b: 160 MPa TQS03c : 200 Mpa TQS03d: 120 MPa H. Felice After cool-down

TQS03 training 10/17/2013H. Felice6 TQS03 series demonstrated -Progressive degradation: but only 5 % from a to c -Permanent degradation beyond 200 MPa preload -QXF should have margin Magnet: pole turn (preload) / max midplane stress (excitation) TQS03a: / -190 MPa TQS03b: / -240 MPa TQS03c : / -260 Mpa TQS03d: / -190 Mpa Quench location: Midplane area

HQ series overview HQ01 a-b-c-d-e Magnets with mixed coils Coils => 54/61 Coils => 108/127 Performance (LBNL and CERN) 4 magnets => 70 to 85 % Iss at 4.4 K HQ01e test at CERN => 85 % at 1.9 K HQ02a and a2 Same conductor in all coils Coils => 108/127 Performance (FNAL) 98 % at 4.5 K 89 % at 2.2 K A. Godeke 10/17/2013H. Felice7 2 of each / magnet

HQ series performance overview HQ01 series HQ02 Reached 80% in 2 quenches Good memory What changed? The coil fabrication Cable with Stainless steel core HQM04 97% at 4.5 K 94% at 2.2 K Maxim Marchevsky Guram Chladidze 10/17/2013H. Felice8

Impact of coil fabrication Review of the coil fabrication process and design  High compaction of the winding during fabrication  Tooling and coil design oversight: no margin to allow for cable expansion  Risky end design Suspected to be the cause of conductor degradation in potted coils Main requirement for HQ02 coils: using the same tooling as HQ01 Accounting for dimensional changes and interlayer insulation  Smaller cable with smaller strand => mm diameter strand => 14.8 mm x mm  Axial gap size 4 mm/m Revision of the end parts design 10/17/20139H. Felice Lead end R, Hafalia, S, Caspi

HQ experience applied to QXF conductor Cable dimensional change accounted for in the magnetic design and tooling design 4.5 % in thickness and 2 % in width in ROXIE cross-section Design made with reacted cable dimensions Based on HQ and LQ experimental data Importance to provide actual cable dimensional changes data for QXF cable to magnet designers 10/17/2013H. Felice10

Impact on coil fabrication schedule Last HQ01 coil #9 completed end of 2010 HQ01d and e tested starting April st Mirror test at FNAL HQM01 2 nd Mirror test at FNAL HQM02 1 less turn 91 % Iss at 4.6 K 89 % Iss at 2.2 K 3 rd Mirror test at FNAL HQM04 New end parts New cable HQ02 tested at FNAL To validate compaction theory 09/ / / /2011 Unforeseen change of cable in the case of HQ02 delayed strongly the magnet production QXF 2 nd generation cable should be defined very early to facilitate implementation 10/17/2013H. Felice11

HQ Winding Experience HQ01: 1 st generation of coils 2 pass cable Mechanically stable HQ02: 2 nd generation of coils 1 pass cable to implement the stainless steel core “Easy” popped strands noticed by technicians in some coils Easily fixable HQ02 experience => Learning experience on how to handle less mechanically stable cables 10/17/201312H. Felice D. Dietderich - F. Borgnolutti

Impact of SS core in HQ performance 10/17/201313H. Felice X. Wang, J. DiMarco, M. Marchevsky – Guram Chladidze HQ01 / HQ02 performance Beneficial effect on ramp rate dependence Beneficial effect on field quality

Summary 10/17/2013H. Felice14 LARP short models performance widely influenced by all the production chain Best examples: HQ01 to HQM04 / HQ02 With coil fabrication improvement => performance improvement despite low RRR in coil 15 What to remember from short model program for QXF Cable Beneficial effect of the core cable on field quality and ramp rate dependence let’s keep in mind the potential delay to implement a new cable design Coil fabrication / tooling design: Data for Effective dimensional changes in the design Assembly: Stress level in conductor => TQS03 is a good guideline