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Development of a Short Model of theSuperconducting Separation Dipoles D2 for theHigh Luminosity Upgrade of LHCP.Fabbricatore INFN-Genova

Development of a Short Model of the Superconducting Separation Dipoles D2 for the High Luminosity Upgrade of LHC

P.Fabbricatore, A.Bersani, B.Caiffi, R.Cereseto and S. Farinon (INFN Genova)

A.Foussat and E.Todesco (CERN)

• The separation/recombination D2 dipoles

• Updated D2 design

• The short model development

• Next Steps

This work has been performed in the framework of an agreement CERN-INFN

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The D2 dipoles in HL-LHC: Larger aperture and integrated B strength wrt the D2 dipoles presently in LHC

Characteristics Units ValueAperture mm 105Distance between apertures mm 188

Magnetic length m 7.78Bore field T 4.5Peak field T 5.26Current kA 2.34Temperature K 1.9Load line margin (%) 38Overall current density A/mm2 443Stored energy MJ 2.28

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Magnet lay-out

• Asymmetric coils • Double collars• Separate collar

poles

• Elliptical yoke

• Al-alloy sleeves• Longitudinal tie-

rods

Choices determined by Field Quality and Construction Feasibility/Simplicity

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Details of collared coils integrated into the Al-alloy sleeves

Why Al sleeve solution?

• Repulsive horizontal force up to 196 kN/m

• Collar dimensions and shape determined by the iron geometry magnetically optimised

FxFx

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Integrated Magnetic Field quality

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Short Model

• In 2016 the D2 design achieved a degree of maturity allowingmoving to the following step consisting in the construction ofa short model to be tested at CERN in 2018.

• Aim: checking the design choices and verifying the feasibilityof the magnetic cross talk compensation through asymmetriccoils.

• Activity performed in the framework of a collaborationbetween CERN and INFN having as objectives not only thedevelopment of a short model but also the construction of afull length prototype within the end of 2019.

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• Outer diameter of external shell 630 mm• Magnetic length 1350 mm• The iron yoke (blue) is not covering the coil ends for limiting the peak field

in these regions. The magnetic steel is here replaced by stainless steel.

Short Model Dimensions

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Short Model: connection side

• No external shell

• Mostly same as the final magnet

• Suspending system for cryogenic test in vertical

• Electrical connection to current leads

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Short Model: opposite to connection side

• Pre-stress up to 250 kN with six tie-rods loaded through super-bolts

• Two central φ33 mm tie_rods

• Four lateral φ25 mm tie_rods

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Main Steps of the Construction Process

• Single collared coils are constructed

• The two coils are integrated into the Al-alloy sleeves with a geometrical gap 0.2mm- 0.3 mm. (During the cool-down the gap will close)

• The two collared coils coupled through the sleeves are integrated into the two halves of the iron yoke (with a geometrical gap of 1.2 mm between them) using a press (270 t/m).

All construction steps, as part of the magnet hystory, were studied trough FE mechaical analysis

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Moke-up for collared coil integration simulation (0.2 mm gap)

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Coil Ends- End Spacers –Winding Tests

The coils of D2 magnet are asymmetric, causing some complication in the winding operation and requiring attention in the end spacer design.

Preliminary end spacers constructed with a 3D printers and used for winding tests.

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• The development of the separation/recombinationdipoles D2 for the High Luminosity upgrade of LHC movedfrom design to model construction phase.

• The constructive design has required some designchanges and has underlined some critical operations,requiring specific studies for collared coil integration andcoil ends.

• The construction of the model is planned to be completedwithin spring 2018. It will be followed by the constructionof a full length prototype, presently under engineeringdesign phase, which is taking advantaged from thelessons learned with the short model construction

CONCLUDING REMARKS AND NEXT STEPS

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SPARE SLIDES

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VM STRESSES IN COLLARS AND SLEEVES BEFORE COOL-DOWN

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VM STRESSES IN COLLARS AND SLEEVES AFTER COOL-DOWN

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MN

MX

0

.712E+08.142E+09

.214E+09.285E+09

.356E+09.427E+09

.498E+09.569E+09

.647E+09

AUG 25 2017

12:10:14

NODAL SOLUTION

STEP=19

SUB =9

TIME=19

SEQV (AVG)

DMX =.020647

SMN =1493.19

SMX =.602E+09

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MN

MX

45280.4

.862E+07.172E+08

.258E+08.343E+08

.429E+08.515E+08

.600E+08.686E+08

.784E+08

AUG 25 2017

12:40:48

NODAL SOLUTION

STEP=19

SUB =9

TIME=19

SEQV (AVG)

DMX =.283895

SMN =45280.4

SMX =.784E+08

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VM STRESSES IN COLLARS AND SLEEVES AT 1.08% NOMINAL CURRENT

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MN

MX

0

.712E+08.142E+09

.214E+09.285E+09

.356E+09.427E+09

.498E+09.569E+09

.647E+09

AUG 25 2017

12:10:45

NODAL SOLUTION

STEP=40

SUB =4

TIME=40

SEQV (AVG)

DMX =.020496

SMN =4340.01

SMX =.540E+09

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MN

MX

886135

.106E+08.203E+08

.300E+08.397E+08

.494E+08.590E+08

.687E+08.784E+08

.895E+08

AUG 25 2017

12:41:09

NODAL SOLUTION

STEP=40

SUB =4

TIME=40

SEQV (AVG)

DMX =.283829

SMN =886135

SMX =.895E+08

development of a short model of the superconducting separation …€¦ · p.fabbricatore,...

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