MQXF support structure An extension of LARP experience Helene Felice MQXF Design Review December 10th to 12th , 2014 CERN Snapshot of LARP support structure experience Length 2004 0.3 m 1m 3.6-3.7 m 2005 SQ 2006 Subscale quad 2007 2008 LR Long Racetrack TQ Technology Quadrupole LRS01-02 TQS01/02a-b-c/03a-b-c-d 2009 LQ Long Quadrupole 2010 2011 2012 HQ High-field Quadrupole LQS01a-b/02/03 HQ01a-b-c-d-e HQ02a-b / HQ03a 2013 2014 Time Helene Felice 12/10/2014 2 Step-by-step technology demonstration Length 2004 0.3 m 1m 3.6-3.7 m 2005 SQ 2006 Subscale quad Concept 2007 2008 TQ Technology Quadrupole 2009 TQS01/02a-b-c/03a-b-c-d Concept on cos2q Technology selection LR Long Racetrack LRS01-02 Length demonstration Scale-up & design optimization 2010 2011 2012 2013 HQ High-field Quadrupole LQ Long Quadrupole LQS01a-b/02/03 Some accelerator quality features Length with cos2q Accommodating variability in coil dimension HQ01a-b-c-d-e HQ02a-b / HQ03a Accelerator quality features Mechanical alignment 2014 Time Helene Felice 12/10/2014 3 Exploration of the stress limits Length 2004 0.3 m 1m 3.6-3.7 m 2005 SQ 2006 Subscale quad Concept 2007 LR Long Racetrack 2008 TQ Technology Quadrupole 2009 TQS01/02a-b-c/03a-b-c-d Concept on cos2q Scale-up & design optimization Technology selection Ultimate stress exploration 2010 2011 2012 2013 2014 HQ High-field Quadrupole LRS01-02 Length demonstration LQ Long Quadrupole LQS01a-b/02/03 Some accelerator quality features Length with cos2q Accommodating variability in coil dimension HQ01a-b-c-d-e HQ02a-b / HQ03a Accelerator quality features Mechanical alignment High stress regime Time Helene Felice 12/10/2014 4 Outline • Shell-based support structure concept • Exploring the limits – TQ high stress • Step-by-step technology demonstration – Design optimization – Length • QXF support structure – Main features Helene Felice 12/10/2014 5 Shell-based support structure Motivation and concept • Shell-based support structure often referred as “bladder and keys” structure developed at LBNL for strain sensitive material coil pad shell Helene Felice 12/10/2014 6 Shell-based support structure Supporting tools • Numerical tools • Instrumentation • • • Helene Felice Assembly based on analysis Control of the pre-stress level Constant feedback between SG measurements and model 12/10/2014 7 Shell-based support structure Concept • Shell-based support structure often referred as “bladder and keys” structure developed at LBNL for strain sensitive material Helene Felice 12/10/2014 8 Shell-based support structure Concept Inflated Bladders • Shell-based support structure often referred as “bladder and keys” structure developed at LBNL for strain sensitive material Bladder Displacement scaling 30 Helene Felice 12/10/2014 9 Shell-based support structure Concept Shimming of the load leys • Shell-based support structure often referred as “bladder and keys” structure developed at LBNL for strain sensitive material Bladder Keys Displacement scaling 30 Helene Felice 12/10/2014 10 Shell-based support structure Concept Cool-down • Shell-based support structure often referred as “bladder and keys” structure developed at LBNL for strain sensitive material Cool-down Bladder Keys Displacement scaling 30 Helene Felice 12/10/2014 11 Shell-based support structure Concept Energized • Shell-based support structure often referred as “bladder and keys” structure developed at LBNL for strain sensitive material With shell structure cold Cool-down Lorentz forces Bladder Room temperature Keys Support structure allowing fine tuning of the Collaring processDisplacement scaling 30 Courtesy of Paolo Ferracin Helene Felice 12/10/2014 12 Shell-based support structure Key features • Gradual application of the preload: no overshoot • Tunable preload – During assembly – In between tests • Reversible assembly process – Allowing replacement of a defective coil if needed • Correlation between models and strain gauges measurements Helene Felice 12/10/2014 13 Outline • Shell-based support structure concept • Exploring the limits – TQ high stress • Step-by-step technology demonstration – Design optimization – Length • QXF support structure – Main features Helene Felice 12/10/2014 14 Stress limits: defining an acceptable range TQS03 program CONDUCTOR • OST RRP 108/127 strand • High RRR • 54 % Cu fraction • Jc (12T, 4.3 K) 2770 A/mm2 • 27 strands cable • 1.26 mm mid-thickness bare • 10 mm width bare • 0.125 mm insulation TQS03 parameters 4.3 K 1.9 K 13.2 14.5 Bpeak ss (T) 12 13 Gss (T/m) 234 254 Iss (kA) 4 tests: TQS03 a, b, c and d • performed with variable pre-stress • TQS03a: 120 MPa • TQS03b: 160 MPa • TQS03c : 200 Mpa • TQS03d: 120 MPa • supported by ANSYS analysis Helene Felice 12/10/2014 15 TQS03a 300K 4.2 K TQS03b 300K 4.2 K TQS03c 300K 4.2 K TQS03d 300K Strain gauges location 4.2 K 3000 200MPa 2500 2000 180MPa 160MPa 160MPa shell T meas eq (me) 1500 Pole T meas 1000 In boxes: sig theta measured shell T ANSYS Pole T ANSYS 500 Add predicted on box 0 -110 MPa -160 MPa -500 -1000 -1500 -120 MPa Good agreement between measurements and ANSYS prediction -190 MPa Helene Felice 12/10/2014 16 100 98 96 Fraction of Iss (%) 94 92 TQS03a 93 % ~ 12.3 / 13.5 kA 90 TQS03b 91 % ~ 12 / 13.2 kA TQS03c 88 % ~ 11.6 / 12.8 kA TQS03d 88 % 88 86 84 82 80 78 4.3 K 1.9 K 4.3 K • Only 5 % degradation from TQS03a to TQS03c • TQS03d did not recover => Permanent degradation Helene Felice 12/10/2014 17 Strain gauge data during excitation TQS03a TQS03b Preload increase Preload increase TQS03c Strain gauge • conclusion Correlation between preload levels and magnet performance allowed the definition of a safe range of transverse stress in Nb3Sn coils Helene Felice 12/10/2014 18 Outline • Shell-based support structure concept • Exploring the limits – TQ high stress • Step-by-step technology demonstration – Design optimization – Length • QXF support structure – Main features Helene Felice 12/10/2014 19 From TQ to HQ Design optimization TQ LQ Plot of stress along the length • No alignment features • Optimization of the design • load key positon • Pad extremity in stainless steel to lower peak field in the end • Implementation of alignment features from pad to shell Helene Felice 12/10/2014 20 From TQ to HQ Design optimization: key position optimization TQ - 90 mm aperture - 12 T peak field - 240 T/m LQ - 90 mm aperture - 12 T peak field - 240 T/m - Fq Layer 1 = -1.5 MN/m - Fq Layer 2 = -1.02 MN/m - Fq Layer 1 = -1.5 MN/m - Fq Layer 2 = -1.02 MN/m 20 MPa -100 MPa 20 MPa -85 MPa Key optimization -187 MPa -171 MPa => Optimization of the key position to improve stress distribution Helene Felice 12/10/2014 21 From TQ to HQ Design optimization TQ • No alignment features LQ • Optimization of the design • load key positon • Pad extremity in stainless steel to lower peak field in the end • Implementation of alignment features from pad to shell Helene Felice HQ • Cross-section optimization considering force distribution between layers • Alignment features between coil and pads: aluminum collars and key 12/10/2014 22 From TQ to HQ Design optimization: key position optimization TQ - 90 mm aperture - 12 T peak field at 4.3 K - 240 T/m LQ - 90 mm aperture - 12 T peak field at 4.3 K - 240 T/m HQ - 120 mm aperture - 14 T peak field at 4.3 K - 200 T/m - Fq Layer 1 = -1.5 MN/m - Fq Layer 2 = -1.02 MN/m - Fq Layer 1 = -1.5 MN/m - Fq Layer 2 = -1.02 MN/m - Fq Layer 1 = - 2.1 MN/m - Fq Layer 2 = - 2.6 MN/m 20 MPa -100 MPa 20 MPa -85 MPa MPa MPa -187 MPa Key Xsection optimization optimization -171 MPa MPa => Improvement of the cross-section to avoid layer 2 overloading Helene Felice 12/10/2014 23 Helene Felice 12/10/2014 24 Stress in HQ Adresses: - Stress distribution - 2D and 3D - Pad ss and iron - Ground for MQXF stress level Helene Felice 12/10/2014 25 Outline • Shell-based support structure concept • Exploring the limits – TQ high stress • Step-by-step technology demonstration – Design Optimization – Length • QXF support structure – Main features Helene Felice 12/10/2014 26 1st long shell based structure: the Long Racetrack LR • LRS01: full length shell Magnet parameters • • • q E (1 ) 2 Friction limits the shell contractions • Central part locked Strain at 4.5 K consistent with 0.2 friction model results During excitation e.m. forces induced slippage (e q e z ) Helene Felice 12/10/2014 27 Impact of shell segmentation • LRS01 – High meas. axial strain meas. – Effect on azimuthal stress E (e q e z ) q 2 1 ( LRS ) • LRS02 (with segmented shell) – Reduced axial strain LQS LRS02 LRS01 Helene Felice 12/10/2014 #28 Length demonstration on a cos2q magnet: the Long Quad LQ • • • • 90 mm aperture coils with Ti poles Iron pads, masters, yokes, Al shell Pre-load with bladders and keys TQ coil scale-up • LQS01-2 Short-sample limits (4.5 K – 1.9 K) – Gss: 240 T/m – 267 T/m – Iss: 13.8 kA – 15.4 kA – Peak field: 12.3 T - 13.6 T LQS03 Short sample limit – -Gss: 227 T/m – 250 T/m – Iss: 12.9 kA – 14.4 kA – Peak field: 11.5 T - 12.8 T • • • End support: plate and rods Magnet/coil length: 3.7/3.4 m Helene Felice 12/10/2014 29 Mechanical Analysis Typical Stress distribution Pole q (MPa) Preload for 240 T/m: 471 kN z and ez at 300 K - target (3D): +88 Mpa (178 kN) +455 me z and ez at 4.3 K - target (3D): + 239 MPa + 1138 me Preload for 260 T/m q and eq at 300 K - target (3D): -82 MPa -580 me q and eq at 4.3 K - target (3D): -157 MPa -1031 me 149 156 163 170 177 184 191 198 208 212 q (MPa) -198 -180 -162 -143 -125 -107 -88 -70 -51 -33 70 60 End contact pressure (MPa) Preload for 260 T/m q and eq at 300 K - target (3D): + 56 MPa + 750 me q and eq at 4.3 K - target (3D): + 183 MPa +2080 me Rod End Contact pressure (Mpa) Shell 50 40 30 20 NO gap 10 0 293 K -0.2 0 0.2 0.4 0.6 0.8 1 Fem/Fem_240T/m Helene Felice 12/10/2014 30 Axial strain in shell Helene Felice 12/10/2014 31 Production readiness: Accommodating coil size variation shell Strain Gauge measured Expected coil Strain Gauge 92 % at 4.5 K LQS01b Pole Strain Gauge LQS01a LQS01a pad Nominal Oversized Helene Felice 12/10/2014 32 Outline • Shell-based support structure concept • Exploring the limits – TQ high stress • Step-by-step technology demonstration – Alignment features – Length • QXF support structure – Main features Helene Felice 12/10/2014 33 From LARP to MQXF Helene Felice 12/10/2014 34 MQXF support structure overview • Show how the key features described before are found in MQXF support structure design • Point to Mariusz’s talk Helene Felice 12/10/2014 35
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