MQXF support structure An extension of LARP experience Helene Felice MQXF Design Review December 10...

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MQXF support structureAn extension of LARP experience

Helene Felice

MQXF Design Review December 10th to 12th , 2014

LQLongQuadrupoleLQS01a-b/02/03

LRLong RacetrackLRS01-02

HQHigh-field QuadrupoleHQ01a-b-c-d-eHQ02a-b / HQ03a

Snapshot of LARP support structure experience

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Length

0.3 m 1 m 3.6-3.7 m

SQSubscale quad

TQTechnology QuadrupoleTQS01/02a-b-c/03a-b-c-d

LRLong RacetrackLRS01-02Length demonstration

LQLongQuadrupoleLQS01a-b/02/03Some accelerator quality featuresLength with cos2qAccommodating variability in coil dimension

HQHigh-field QuadrupoleHQ01a-b-c-d-eHQ02a-b / HQ03aAccelerator quality featuresMechanical alignment

Step-by-step technology demonstration

Length

0.3 m 1 m 3.6-3.7 m

SQSubscale quadConcept

TQTechnology QuadrupoleTQS01/02a-b-c/03a-b-c-dConcept on cos2qTechnology selection Scale-up & design optimization

LRLong RacetrackLRS01-02Length demonstration

LQLongQuadrupoleLQS01a-b/02/03Some accelerator quality featuresLength with cos2qAccommodating variability in coil dimension

HQHigh-field QuadrupoleHQ01a-b-c-d-eHQ02a-b / HQ03aAccelerator quality featuresMechanical alignmentHigh stress regime

Exploration of the stress limits

Length

0.3 m 1 m 3.6-3.7 m

SQSubscale quadConcept

TQTechnology QuadrupoleTQS01/02a-b-c/03a-b-c-dConcept on cos2qTechnology selectionUltimate stress exploration

Scale-up & design optimization

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

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Shell-based support structureMotivation and concept

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• Shell-based support structure often referred as “bladder and keys” structuredeveloped at LBNL for strain sensitive material

Shell-based support structure Supporting tools

• Numerical tools

• Instrumentation

• Assembly based on analysis• Control of the pre-stress level• Constant feedback between

SG measurements and model

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Shell-based support structureConcept

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Displacement scaling 30

Inflated Bladders

Bladder

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Shimming of the load leys

Bladder

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Cool-down

Bladder

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Energized

Lorentz forces

Cool-down

Bladder

Room temperature

Collaring process- Courtesy of Paolo Ferracin

With shell structure

Support structure allowing fine tuning of the

Shell-based support structureKey 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

Outline

Stress limits: defining an acceptable rangeTQS03 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

TQS03parameters

4.3 K 1.9 K

Iss (kA) 13.2 14.5

Bpeak ss (T) 12 13

Gss (T/m) 234 254

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

Strain gauges location

In boxes: sig theta measured

Add predicted on box

300K 4.2 K 300K 4.2 K 300K 4.2 K 300K 4.2 K

TQS03a TQS03b TQS03c TQS03d

e q(me)

shell T meas

Pole T meas

shell T ANSYS

Pole T ANSYS

-160 MPa

-120 MPa-190 MPa

-110 MPa

200MPa180MPa

160MPa 160MPa

Good agreement between measurements and ANSYS prediction

f I ss(%

TQS03a

TQS03b

TQS03c

TQS03d

4.3 K 1.9 K 4.3 K

~ 11.6 / 12.8 kA

• Only 5 % degradation from TQS03a to TQS03c• TQS03d did not recover => Permanent

degradation

~ 12 / 13.2 kA

~ 12.3 / 13.5 kA

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Strain gauge data during excitation

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Strain gauge

• conclusion

TQS03a

TQS03b

TQS03cPreload increase

Preload increase

Correlation between preload levels and magnet performance allowed the definition of a safe range of transverse stress in Nb3Sn coils

Outline

From TQ to HQDesign optimization

• No alignment features

Plot of stress along the length

• 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

From TQ to HQDesign optimization: key position optimization

TQ - 90 mm aperture- 12 T peak field - 240 T/m

- Fq Layer 1 = -1.5 MN/m- Fq Layer 2 = -1.02 MN/m

LQ- 90 mm aperture- 12 T peak field - 240 T/m

-100 MPa

-187 MPa

-85 MPa

-171 MPa

optimization

=> Optimization of the key position to improve stress distribution

20 MPa 20 MPa

From TQ to HQDesign optimization

TQ LQ HQ

• No alignment features

• Cross-section optimization considering force distribution between layers

• Alignment features between coil and pads: aluminum collars and key

• 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

From TQ to HQDesign 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 = - 2.1 MN/m- Fq Layer 2 = - 2.6 MN/m

-100 MPa

-187 MPa

-85 MPa

-171 MPa

Xsection

optimizationKey

optimization

=> Improvement of the cross-section to avoid layer 2 overloading

20 MPa 20 MPa MPa

Stress in HQ

Adresses:- Stress distribution

- 2D and 3D- Pad ss and iron- Ground for MQXF stress level

Outline

– Design Optimization– Length

1st long shell based structure:the Long Racetrack LR

• LRS01: full length shell• 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

Magnet parameters

( )( )zE ee

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Impact of shell segmentation

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• LRS01– High meas. axial strain meas.– Effect on azimuthal stress

• LRS02 (with segmented shell) – Reduced axial strain

( )( )zE ee

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Length demonstration on a cos2 q magnet:the Long Quad LQ

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• 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

Preload for 240 T/m: 471 kNsz and ez at 300 K- target (3D): +88 Mpa (178 kN)

+455 mesz and ez at 4.3 K- target (3D): + 239 MPa + 1138 me

-0.2 0 0.2 0.4 0.6 0.8 1

Fem/Fem_240T/m

Preload for 260 T/msq and eq at 300 K - target (3D): -82 MPa

-580 mesq and eq at 4.3 K - target (3D): -157 MPa -1031 me

s q (MPa)

Mechanical AnalysisTypical Stress distribution

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Preload for 260 T/msq and eq at 300 K- target (3D): + 56 MPa

+ 750 mesq and eq at 4.3 K- target (3D): + 183 MPa +2080 me

s q (MPa)

NO gap

-198-180-162-143-125-107-88-70-51-33

149156163170177184191198208212

Axial strain in shell

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Production readiness:Accommodating coil size variation

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Expected

measured

shell Strain Gauge

coil Strain Gauge

Nominal

padPole StrainGauge

LQS01a

Nominal Oversized

padPole StrainGauge

92 % at 4.5 K

LQS01aLQS01b

Outline

– Alignment features– Length

From LARP to MQXF

MQXF support structure overview

• Show how the key features described before are found in MQXF support structure design

• Point to Mariusz’s talk

MQXF support structure An extension of LARP experience Helene Felice MQXF Design Review December 10...

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