ILC Main Linac Superconducting Quadrupole V. Kashikhin for Superconducting Magnet Team.

ILC Main Linac Superconducting Quadrupole

V. Kashikhin for Superconducting Magnet Team

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Outline

• Split quadrupole issues • Quadrupole concept• Conductive cooling• Magnetic design• Installation and disassembly• Summary

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Split Quadrupole Concept Design Team

• Miao Yu- Cooling down analysis• Mauricio Lopes- Magnetic center shift• Yuri Orlov- 3D design and integration• Vladimir Kashikhin- Magnet concept

The Quadrupole concept was designed in short period of time by:

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Splittable Quadrupole Issues

Task from ILC Project Management: Look at the Split Quadrupole conceptual design to provide the quadrupole package installation and replacement outside of a very clean room. Main issues:

• Stable magnetic and mechanical design;• Effective conductive cooling;• Easy installation and disassembly;• Quadrupole+BPM rigid connection;• Magnetic axis stability;• Quench protection.

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ILC Quadrupole Specification

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Quadrupole Mechanical Concept

It was chosen the quadrupole design with racetrack coils which easy to split in vertical or horizontal direction.

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Quadrupole Fabrication• Qudrupole laminated yoke consists of two halfes;• Laminations stamped with accuracy 20 microns;•  Long calibrated rods connect two thick side plates and laminations in the solid unit;• Two coils mounted in each half core.•There is an easy assess to provide accurate coil mounting relatively pole and provide the coil frame prestress;• The half units identical and exchangable;• All current leads should be heavily stabilized with extra copper material.

Split plane

Built and Tested Quadrupole Model 1

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Quadrupole Wiring SchemeQuadrupole consists of 4 coils.Each coil has 3 sections of NbTi superconductor: one is for quadrupole and two for vertical and horizontal dipoles.There is also heaters in each coil wound from a stainless steel wire.Quadrupole and dipole sections connected in quadrupole and dipole configuration as shown in figure.The connections easy to rearrange for split configuration

Split line

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Quadrupole Cooling-Down • The quadrupole will be cooled using conductive

cooling;• Five heat transfer leads will thermally connect quadrupole core and LHe supply line;• The cross-section of leads 50 mm x 10 mm;• Cooling down time for the cryomodule is 30 hours;• During cooling initially the cold He gas goes through supply line and temperature changes from 300 K to 2 K. In such regime the enthalpy of the cold gas between 4.2 K and 300 K is utilized as well;• To cool down 1 kg steel from 300 K to 2 K is needed to evaporate 0.8 liters of LHe;• The quadrupole mass is ~ 280 kg.

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Conductive Cooling Animation 

Quadrupole cooled down from 300K to 3.5K in 38 hours.

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Magnet Assembly TolerancesCase # Description

0 Standard ML quadrupole. Gradient 54 T/m. No correction coils.

1 Right half of the magnet displaced 40 microns up.

2 1st Quadrant displaced 40 microns up.

3 1st Quadrant displaced 40 microns right and 40 microns up.

4 Coil displaced 100 microns up.

5 Coil displaced 100 microns up and 100 microns right.

N1 40um up

N2 40um up

N3 57um up

N4 100um upN5 140um

1 unit = 1 Gauss= 1um

Magnetic center shift in microns

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Quadrupole Blocks  

Half Quadrupole

Quadrupole Assembly

Quadrupole with Cooling Leads

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Half Quadrupole with Beam Pipe View

Half Quadrupole Yoke

Beam Pipe

Quadrupole-BPM Connection Flange

Quadrupole Supports

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Quadrupole with Beam Pipe View 

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Quadrupole with BPM 

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Cryomodule Cross-Section 

Quadrupole Package

2 Phase He Supply Pipe

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Quadrupole with BPM Cross-Section

Quadrupole

BPM

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Cryomodule Cross-Section 

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Quadrupole Side View 

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Cryomodule Cross-Section 

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Cryomodule Cross-Section 3D View (1)

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Cryomodule Cross-Section 3D View(2)

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Quadrupole Final Assembly View 

Quadrupole

Cooling Leads BPMCurrent Leads

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Summary • The first look at the splittable quadrupole showed this

approach visibility;• Proposed the quadrupole concept with vertical split;• Quadrupole has a conduction cooling from LHe supply pipe;• Quadrupole mounted around beam pipe outside of the clean room;• BPM has tight connection with quadrupole;• Quadrupole bolted to the strong 300 mm diameter He gas return pipe;• Special attention paid on the magnet assembly and mounting tolerances;• Current leads also conductively cooled;• Magnet cooling down time ~ 38 Hours;• The Quadrupole model with split should be built and tested to verify the design.