2 nd Joint HiLumi LHC – LARP Annual Meeting INFN Frascati – November 14 th to 16 th 2012 Helene...

2nd Joint HiLumi LHC – LARP Annual MeetingINFN Frascati – November 14th to 16th 2012

Helene FelicePaolo Ferracin

LQ Mechanical Behavior Overviewand Next Steps

2

Overview

• Magnet Overview

11/14/2012 2nd Joint HiLumi LHC - LARP Annual Meeting - H. Felice

• Mechanical analysis and SG data comparison

• Next steps

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240after loading 4.2 K

Mea

sure

d St

ress

(M

Pa) LQS01a - shell

LQS01a - PoleT

LQS01b - shell

LQS01b - PoleT

LQS02 - shell

LQS02 - PoleT

LQS03 - shell

LQS03 - PoleT

2nd Joint HiLumi LHC - LARP Annual Meeting - H. Felice

3

LQ Design overview

• 90 mm aperture coils with Ti poles • Iron pads, masters, yokes, Al shell• Pre-load with bladders and keys

• 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

11/14/2012

4

LQ assembly

• Total of 60 gauges mounted (q and z)• 20 on shell, 32 on coil poles, 8 on rods• Four axial locations along coil length



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LQ strain gauges

• Shell and coil stations– q and z gauges thermally

compensated– 10 shell stations– 4 stations per coil

• 2 gauges/rod => 1 signal/rod• Total of 60 gauges

11/14/2012

Measurements presented here are averages of the various gauges

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Mechanical AnalysisTypical Stress distribution

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)

Shell

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

Rod

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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)

Pole

NO gap



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LQSD: structure validation

11/14/2012

• Loading and cool-down to 77K with aluminum dummy coils

• Validation of the structure behavior


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Mea

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LQS01a - shell

LQS01a - PoleT

LQS01a SummaryAzimuthal stress

LQS01a Gradient preload: 230-240 T/m

Nominal Oversized

From LQS01a to LQS01bReduction of the radial shimming from 30 to 15 mils

Fuji Test to confirm

LQS01b LQS01a

Some unloading of the pole suggested lack of preload

11/14/2012

30 mils ~ 750 mm

Radial shim thickness


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LQS01b SummaryAzimuthal stress

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LQS01a - shell

LQS01a - PoleT

LQS01b - shell

LQS01b - PoleT

LQS01a Gradient preload: 230-240 T/mLQS01b Gradient preload: 260-270T/m

LQS01b loading required a bladder pressure of 8000 psi = 55 MPa

11/14/2012


30 mils ~ 750 mm

15 mils ~ 375 mm


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LQS02 SummaryAzimuthal stress

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LQS01a - shell

LQS01a - PoleT

LQS01b - shell

LQS01b - PoleT

LQS02 - shell

LQS02 - PoleT

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Shell azimuthal microstrain

Oversized coil 2DNominal 3DLQS01a before cool-down LQS01b loadingLQS02a loading

LQS01a Gradient preload: 230-240 T/mLQS01b Gradient preload: 260-270T/mLQS02 Gradient preload: 260-270 T/m

11/14/2012


30 mils ~ 750 mm

15 mils ~ 375 mm15 mils ~ 375 mm


11

LQS03 assembly target and motivation

• LQS03 assembly target were chosen identical to LQS02 assembly targets

• Some uncertainty about the reason behind the lack of performance of LQS02• Concern about mid-plane block quenches

- conservative approach in keeping the same preload - 1-to-1 comparison with LQS02 – only change of conductor- Unloading of the pole can be handled by a “healthy magnet” => TQS03a

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Imag

(A)

Training Quench #

LQS01a - 4.5 K LQS01a - 3.1 KLQS01a - 4.3 K LQS01a - 1.9 KLQS01b - 4.5 K LQS01b - 3 KLQS01b - 1.9 K LQS01b - 2.3 - 4KLQS02a - 20 A/s - 4.5 K LQS02a - ramp-rate - 4.5 KLQS02a - ramp-rate - 2.6 K LQS02a - ramp-rate - 1.9 K

227 T/m

209 T/m93% Iss

11/14/2012


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LQS03 Loading conditions

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LQS01a - PoleT

LQS01b - shell

LQS01b - PoleT

LQS02 - shell

LQS02 - PoleT

LQS03 - shell

LQS03 - PoleT

56 MPa

-82 MPa

11/14/2012

LQS01a Gradient preload: 230-240 T/mLQS01b Gradient preload: 260-270T/mLQS02 Gradient preload: 260-270 T/mLQS03 same preload as LQS02

Comparison of SG data during assembly


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LQS01a

SG shell data during assembly

11/14/2012

57 +/- 8 MPa

LQS03

LQS01b

34 +/- 8 MPa67 +/- 6 MPa

LQS02

56 +/- 8 MPaShell SG behave

consistently during

assembly


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SG Rod data during assembly

11/14/2012

92 +/- 3 MPa

LQS03

LQS01a

60 +/- 3 MPa 94 +/- 5 MPa

LQS01b

LQS02

92 +/- 2 MPaRod SG behave

consistently during

assembly


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SG Coil Pole pieces data

11/14/2012

-77 +/- 21 MPa

LQS01a

LQS03

+5 12 MPa

LQS01b

LQS02

-107 26 MPa

After LQS01a:-SG in compression-Large spread

-69+/- 27 MPa

SG Comparison during cool-down


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SG shell data during cool-down

LQS03

LQS01a LQS01b

LQS02

Shell SG behave consistently

during cool-down

183+/- 9 MPa

199+/- 8 MPa

177+/- 9 MPa

147+/- 6 MPa

11/14/2012


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SG rod data during cool-down

LQS03

LQS01a LQS01b

LQS02

Rod SG behave

consistently during cool-

down

230+/- 10 MPa

235+/- 10 MPa

197+/- 11 MPa

239+/- 9 MPa

LQS03

11/14/2012


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SG Coil Pole pieces data during cool-down

LQS01a

LQS01b

LQS02

11/14/2012

LQS03

-179+/- 104 me

-764+/- 372 me


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LQS03 SG Investigation

• No correlation in terms of station location• No correlation in terms of coil• No correlation between T and Z

• Amplitude of SG signals is inconsistent with magnet performance• Impact on the magnet performance are unclear:

• No signs of mechanical motion recorded during training

• Temperature compensator might be in cause• SG de-bonding?• Might require a visual inspection

11/14/2012


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Excitation

11/14/2012

LQS01a

LQS01b

LQS03• SG in tension still respond to

excitation• Slightly different rate of

unloading observed from one coil to the other


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LQS03 Warm upShell and rods SG

11/14/2012

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S4BT716 +/- 101 me 584 +/- 101 me

Shell remains consistentUsual relaxation after the first test

Rods recover their initial tension


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LQS03 Warm upCoil pole SG

11/14/2012

• After warm-up, the SG do not recover the initial strain and still read some tension


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LQ series: Summary on mechanical performance

• Trust in the capability of the structure to provide required preload: • LQSD• Linear unloading of the poles monitored by SG

• Shell and rods are behaving according to the FEM

• Absolute value of pole pieces SG cannot be trusted

• Challenge resides in the coil size and matching between pads and coil OD

• Impact on the magnet performance are unclear:• No signs of mechanical motion recorded during training

11/14/2012


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Next steps

Option 1: increase of preload• Some concern:

• Risk of damaging the outer layer• Mid-plane quenches in LQS02• Signs of pole unloading in LQS02

• Limit in bladder pressure• LQS03: 7500 psi (52 Mpa)

Option 2• A this point: complete disassembly seems to be the way to learn something

• 3 to 4 months from magnet at LBL to magnet ready to be shipped to FNAL

• After disassembly: coil inspection – 2 possible outcomes:• Signs of damage on the SG => repair => reassembly• No sign of damage of the SG => ?

11/14/2012

2 nd Joint HiLumi LHC – LARP Annual Meeting INFN Frascati – November 14 th to 16 th 2012 Helene...

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