LHC - KEK · 1- Shim correction 0.13 Toshiba 19 Production 2 Repeat Toshiba Full-scale 1 -0.56 Toshiba Proto 5 Reproducibility -0.81 Toshiba 4 Reproducibility -0.77 KEK KEK (Toshiba)-0.72

LHC

2007.11.2 KEK

Outline

• LHC: Overview of Superconducting Magnet System• MQXA Development at KEK

– Design Overview– In-house R&D– Production, Test and Measurement

• Work for Magnet at CERN• Cryogenics System for LHC• Incidents and Failures• Hardware Commissioning• Summary

LHC and Experimental Insertions

Circumference: 27 kmInjection Energy: 450 GeV (p)Collision Energy: 7+7 TeVPeak Luminosity: 1034 cm-2 sec-1

2*4 ExperimentalInsertions

* 450 GeV beam commissioninganticipated in May 2008.

And other insertions forRF, Dump, Cleaning

Critical surface of NbTi (from Wilson textbook)

Critical current of best Cu/NbTi with

typical 3 T field shift at superfluid

helium (INFN-LASA lab, february 2000)

Critical current density vs field measured on

NbTi multiflamentray wire at 4.22 and 2.17 K

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

11000

0 1 2 3 4 5 6 7 8 9 10 11 12

Btot (T)

Jc(A

/mm

2)

LHe HeII

LHC 1.9K ??

Magnets CoolingScheme

Main dipole27.5*1232=34000 t 1.9K

Magnets for Arc

MBMain Dipole

•••

••

MQ : Main Quad

CERN- CEA collaboration

392Magnets for Arc

Layout of Experimental Insertions

Dispersion suppressor Matching section Separation dipoles Finalfocus

IP

KEK, FNAL,LBL, CERN

BNL, BINPCERNCERN

IP

Magnet issues:- Aperture- Field quality- Alignment- Beam heat load

56 mm ID coil

G = 200 T/m at 1.9 K

I = 5390 A

E = 64.3 kJ/m/aperture

Lmag = 2.4/3.4/4.8 m

• Two-layer, non-graded coil.

• Free standing collars, fully

supporting the forces.

• Two-in-one iron yoke.

86

• Four-layer, graded shell coil.

• Free standing collars, fully

supporting the forces.

• Two-in-one iron yoke.

70 mm ID coil

G = 160 T/m at 4.5 K

I = 3620 A

E = 141 kJ/m/aperture

Lmag = 3.4

24

Fermilab

(MQXB)

KEK

(MQXA)16+16

G = 215 T/m, Aperture = 70 mm ~ 9 TL= 5.5 or 6.37 mHigher Order Multipoles < 1 unit (10-4)Beam Heating: 5 ~ 10 W/m

5000

LHC

The Low-Beta InsertionKey Elements to Achieve High Luminosity….

MQXA MQXB MQXAMQXB

6.372.985

5.5 5.52.715

6.37

MCBXAMCBXH/V

b3

b6

MCBXMCBXH/V

MQSX

1.0

TASB

MCBXMCBXH/V

Q3 Q2 Q1

MCSOXa3

a4

b4

DFBX

IP

• Quadrupoles: Low-Beta Triplet

Q1 & Q3 (MQXA): KEK Q2a & Q2b (MQXB): FNAL

Correctors: CERN• Cryostat Assembly

All done by FNAL• Feed boxes for the inner triplet

DFBX: LBNL

CERN-US-KEK Collaborationfor the Low-Beta Insertions

CERNCorrectorsInstallation in the LHC tunnel

FNALMQXB: 16 + spareCryostats (assembly)

BNLSeparation Dipoles: 20

LBLDFBX: 8TAS&TAN: 4

KEKMQXA: 16 + spare

Correctors

Quad. cold masses

Cryostats

Outline




Design Features

• Four Layer Coils – Two 2-layer coils

– with current grading• Inner & outer SC cables• Higher J at outer coil

• Spacer-Collars– High-Mn steel

• Low & stable permeability

• Flux Return Yoke– Horizontally split

– Keyed structure• Pre-stress & mechanical support• Simple & cost-effective assembly

In

OutIn

InOut

Out

Inner Cable

Outer Cable

Design Parameters:Final version

Field gradient 215 T/m Coil inner radius 35 m Yoke outer radius 235 mm Shell outer radius 245 mm Magnetic length 6.37 m Peak field in coil 8.63 T Current 7149 A Superc. load-line ratio 80 % Inductance 87.9 mH Stored energy 2.24 MJ Magnetic force per pole (octant) Fx 1.19 MN/m Fy -1.37 MN/m

1-m Model R&D: In-house Fabrication

1-m Model R&D: Training Quench

190

200

210

220

230

240

250

260

Model #1

Model #1a

Model #1b

Model #2

Model #3

Models #4 & #5

Fie

ld G

radie

nt

(T/m

)

Thermal cycle

Temp.: 1.88 K

Ramp Rate: 10 A/s

Energy Extraction: ~50 %

• Reach to 250 T/m for 1st model.• Exceeding 230 T/m for all models.• Coil design change for 3rd model and later.• Training memory after the thermal cycle.

R&D Work

b6Re-tuned

b10Re-optimized

Reach250 T/m

Notes

0.00

0.01

0.01

0.00

0.03(0.00)

-0.90

-0.93(-0.98)

b10

Toshiba0.13Shim correction1-19

Production

Toshiba Repeat2

Toshiba-0.561Full-scaleProto

Toshiba-0.81 Reproducibility5

KEK-0.77 Reproducibility4

KEK(Toshiba)

-0.72(0.15)

Re-optimize3

KEK-1.62Repeat2

KEK-0.79(0.32)

Original11-m Model

b6ElectromagneticDesign

#

Achievement1-m model reached: 250 T/mFull-scale prototypes: Multiple tuned << 10-4

Optimization

b10 corrected

b6correctedwith shim

10-4

Coil Winding

Courtesy of TOSHIBA

Collaring Preparation

Courtesy of TOSHIBA

Collaring

Courtesy of TOSHIBA

Yoking

Courtesy of TOSHIBA

Cylindering

Courtesy of TOSHIBA

Assembly Complete

Courtesy of TOSHIBA

MQXA Production and Tests

2004 6 20 19 1.9K

0

5

10

15

20

25

0 5 10 15 20 25 30 35 40

ProductionTested at KEK

Num

ber

of m

agne

ts

Month

Started 01-6

04-0103-0102-01

2004-6

1.9 K:• Training quench 230 T/m230 T/m• Full energy dump @215 T/m• Fast Ramp test @150 A/s• Field Measurement• To reach 220 T/m w/o quench• Electrical Insulation Test 1.5 kV @ 4.2 K He-gas

Performance Test at KEK

Room Temperature:- Alignment- Field Gradient,- Error field

Room Temperature:– Alignment check– Field Gradient,– Error Field

Shipping Preparation @ TOSHIBA – Pressure Test– Electrical Test

MQXA from TOSHIBAKEK

24

FNAL

Warm Measurement Setup

Cold Test Station: Vertical Cryostat

Bore Inner TubeInsulation in Vacuum

He I 4.2K

1m Model Magnet

Void Capacity

Rotating Coil

Bore Outer Tube

Pressurized

He II 1.9K

Insulation in Vacuum

-Plate

Heat Exchanger

1.9K

5000

5500

6000

6500

7000

7500

8000

8500

MQXA-P1

MQXA-01

MQXA-02

P1 Inner

P1 Outer

P2 Inner

P2 Outer

P3 Inner

P3 Outer

P4 Inner

P4 Outer

Full Dump by QPH

No Quench

0 5 10 15 20

Quench C

urr

ent

(A)

Quench History of MQXA-03

Feb. 2002 -

10A/sec, 1.9 K

1st Test Cycle 2nd Test Cycle

Run Number

215 T/m

230 T/m

Training Characteristics: MQXA-03

3 quenches to reach 215 T/m9 quenches to reach 230 T/mGood training memory after thermal cycle

Reach 220 T/m w/o quenchFull-energy dump w/ QPH at 215 T/m

Summary of Quench Characteristics

5000

6000

7000

8000

QuenchNo Quench

Que

nch

Cur

rent

(A

)

MQXA-1 2 3 5 4

215 T/m

230 T/m

Quench Sequence

2b

Thermal cycle

Thermal cycle

7 106 9 8 111st T.C.

1912 13

Thermal cycle

14 15112nd

T.C.

16

Bore modification

17 18

0.0

2.0

4.0

6.0

8.0

10

12

14

#1 #2 #3 #5 #4 #2b

#7 #6 #9 #8 #10

#11(

1st)

#12

#13

#14

#11

#15

#16

#17

#18

#19

Straight-SectionLead-EndReturn-End

Num

ber o

f Que

nch

Tra

inin

g

Magnet NumberAll magnets reached 230 T/m.

0.00126.36790.0651217.077227.9

0.00106.36750.0587201.736677.3

0.00096.36700.0581186.536134.4

0.00096.36420.0341101.013207.9

0.00106.36420.020063.4752011.3

0.00486.36320.009612.445392.3

StandardDeviation

AverageStandardDeviation

Average

Magnetic Length (m)Field Gradient (T/m)Current

(A)

MFM: Field Gradient & Mag. Length

Good reproducibility in the order of 10-4

19 units of MQXA

MFM: Higher Order Multipoles

-0.2

-0.1

0

0.1

0.2

a6 a7 a8 a9 a10-2

-1

0

1

2

a3 a4 a5

Multipole-coefficients

an, units

-2

-1

0

1

2

b3 b4 b5 b6

Multipole coefficients

bn, units

-0.2

-0.1

0

0.1

0.2

b7 b8 b9 b10

units : 10000 An , Bn

Quadrupole B2

Generally good within reference values.But, large b4…

@216T/m

Skew

Normal

MQXA

MQXA Cryostating & Test at FNALMQXA

First Test of MQXA

MQXA in LHC Tunnel

Outline




2007.11.27 Dipole

J-PARC

12 6MB(1232 ), MQ(392 ) 2007.3.124

2007.4.26 Dipole

6 superconducting bus

bars 13 kA for B, QD, QF

quadrupole

20 superconducting bus

bars 600 A for corrector

magnets (minimise

dipole field harmonics)

42 sc bus bars 600 A for corrector

magnets (chromaticity, tune, etc….)

+ 12 sc bus bars for 6 kA (special

quadrupoles)

13 kA Protection

diodeTo be connected:

• Beam tubes

• Pipes for helium

• Cryostat

• Thermal shields

• Vacuum vessel

• Superconducting

cables

LHC

web

Cavern

SectorInner Triplet

Outline




Pt 3

Pt 4

Pt 5

Pt 6

Pt 7

Pt 8

Pt 1

Pt 2

Pt 1.8

Cryoplant DistributionPresent Version

Cryogenic plant

Warm CompressorStation

Upper Cold Box

Interconnection Box

Cold Box


Lower Cold Box

Distribution Line Distribution Line

Magnet Cryostats Magnet Cryostats

Cold Compressorbox


Cold Compressorbox


Shaft

Su

rfa

ce

Ca

ve

rnT

unnel

LHC Sector (3.3 km) LHC Sector (3.3 km)

1.8 K Refrigeration Unit New 4.5 K Refrigerator Ex-LEP 4.5 K refrigerator 1.8 K Refrigeration Unit

Pt 3

Pt 4

Pt 5

Pt 6

Pt 7

Pt 8

Pt 1

Pt 2

Pt 1.8

Cryoplant DistributionPresent Version

Cryogenic plant


Upper Cold Box

Interconnection Box

Cold Box


Lower Cold Box

Distribution Line Distribution Line

Magnet Cryostats Magnet Cryostats

Cold Compressorbox


Cold Compressorbox


Shaft

Su

rfa

ce

Ca

ve

rnT

unnel

LHC Sector (3.3 km) LHC Sector (3.3 km)

1.8 K Refrigeration Unit New 4.5 K Refrigerator Ex-LEP 4.5 K refrigerator 1.8 K Refrigeration Unit

Warm Compressor Station of 18 kW @ 4.5 K Cryoplant(Power Input ~4 MW)

LHC 18 kW @ 4.5 K Cold Box

33 kW @ 50 K to 75 K 23 kW @ 4.6 K to 20 K 41 g/s liquefaction

AtmosphericLN2 vaporizer

LN2 Storage at LHC Even Point

–

–

–

–

0.3 MPa4.6 K

0.13 MPa,20 -30 K

WC

S

1.8

K R

efr

ige

rati

on

Un

it

LHe 1.8 K Q1.8K

CC

B

4.5 KRefrigerator

B

D

C

Cold

com

pre

ssors

Turb

lne

Adsor-bers

LHC SectorLoad The four-stage LHC cold compressors

1st stage IHI-Linde

Outline




Incident I: HX buckling

MQXA MQXB MQXAMQXB

Q3 Q2A Q1

DFBX

Q2B

Outer shellInner tube

(copper corrugated)H-piece

30592.7 (RT)

30560.2 (1.9K)

MQXB

Incident I: HX buckling

MQXA MQXB MQXAMQXB

Q3 Q2A Q1

DFBX

Q2B

MQXBLBX

D1

Incident II: Magnet support failure

15cm

GFRP

Incident II: Magnet support failureQ1 Q3

GFRPMQXAMQXB

Q2A Q1

MQXB

Pressure Test after Modification at Pt. 8

25 bar for 1 hour

Succeeded

RF Finger Problem

Plug-In Modules

Damaged Plug-In Modules

Sector 7-8 450 damage

RF Finger Problem

Outline




But.........

Cool-down to 1.9 K at sector 7-8

Cool-down to 1.9 K at sector 7-8

Current Schedule2006 10 2007

2008 5

2 incidents at InnerTripletRF finger

7-8 1.9K

Outline




LHC

Inner Triplet Incident

Sector78 1.9K LSSMain Dipole 1

Sector45 30K

3-4

RF Finger

Inner Triplet System (MQXA ) 2008 1

Documents

LHC - KEK · 1- Shim correction 0.13 Toshiba 19 Production 2 Repeat Toshiba Full-scale 1 -0.56 Toshiba Proto 5 Reproducibility -0.81 Toshiba 4 Reproducibility -0.77 KEK KEK (Toshiba)-0.72