Recent Developments in Nb 3 Sn Dipole Technology at Texas A&M Peter McIntyre Dept. of Physics Texas A&M University [email protected]

Recent Developments in Nb3Sn Dipole Technology at Texas A&MPeter McIntyreDept. of PhysicsTexas A&M [email protected]

The goal: Dipoles for future hadron collidersTAMU4: 14.1 T, 4 x 3 cm2 aperture28 cm2 superconductorCollider-quality field, suppress p.c. multipolesLHC Tripler: 24 T, 56 mm apertureWindings = Bi-2212 inner, Nb3Sn outer

Designing dipoles with Nb3SnThe challengesThe conductor is fragile strain < 0.5%High field limit would be imposed by Lorentz stressFilaments are large snap-back too largeThe solutionsBlock-coil geometry Stress managementHydraulic preloadFlux-plate suppression of snap-back

Stress management

Offload stress from windings to structurestress (PSI) in structure @ 14 Tstress (PSI) in coils only @ 14 T

Field strength decreases smoothly -conductor optimizationMixed-strand cable places Cu strands where they are needed for quench protection.Example: 12 T dipole outer winding can even be NbTi!

Pancake coils are easy to build, control axial stress internally

Center double pancaketop/bottom single pancakes

Provide overall preload using expansion bladdersFlux return split vertically, serves as pistonBladders filled with low-melt Woods metalBladders located between flux return and Al shell2,000 psi pressure delivers full-field Lorentz loadIn cooldown, Al shell delivers additional preload

Suppression of multipoles from persistent current magnetizationPersistent magnetization is generated from current loops within the filaments, Magnetization relaxes via BICs, then snap-back

The steel flux plate redistributes flux to suppress multipoles0.5 T12 T

Multipoles with Persistent Currents5x suppression of p.c. sextupole compensates for larger filament size

Chart1

-1.595974-0.77895-0.228351-0.0414219-0.004346650.2767320.3723840.137370.02512970.00294401

-1.293434-0.59842-0.171858-0.0312378-0.00321959-0.5596690.01360030.044280.008753490.00107504

-1.198689-0.495441-0.140678-0.0260723-0.00260015-1.294068-0.1497520.01710060.001803710.000118523

0.689463-0.429146-0.0924536-0.0250018-0.002216582.246157-0.5014210.0197989-0.00389292-0.00109555

-2.355930.03731910.145097-0.0465447-0.001818543.558058-1.0965050.240223-0.0233829-0.00286578

-3.314620.2044610.225537-0.0502983-0.002099362.481565-0.7003560.285462-0.0320468-0.00300448

-2.3294450.3544210.266148-0.0520716-0.002329192.709996-0.3339760.307086-0.0379222-0.00304299

-1.0823260.4823930.292843-0.0533668-0.002510673.128967-0.04489870.322137-0.0423589-0.00306868

0.4956660.6952610.329052-0.0559052-0.0027673.4086480.3616940.346294-0.0488103-0.00312926

0.2231060.8535070.356333-0.0586819-0.002939872.3336180.6254940.367618-0.0537534-0.00318834

-0.4494770.9777270.378303-0.0612406-0.003074291.2057080.8174190.385879-0.0576752-0.00324932

-0.8957811.0813860.39562-0.0634144-0.003180750.4357270.9628840.401174-0.0607325-0.00331503

-1.1658781.1672340.409817-0.0652558-0.00327405-0.07663471.0777250.413899-0.0631724-0.00337511

-1.3180971.2386690.421695-0.0668059-0.00335513-0.4187661.1718980.424582-0.0651989-0.00342968

-1.3933741.2995110.431723-0.0681402-0.00342537-0.646481.2499440.433768-0.0668988-0.00347999

b2

b4

b6

b8

b10

b2

b4

b6

b8

b10

Central Field

Multipoles

Curved Iron Boundary, with Sc magnetization

Final Design

VLHC Dipole (Short sample limit @4.2K 12 Tesla )2/6/013.1415926536

Dipole (3;3)cm bore.37%Cu to allThe amount of strands and cables for The Short Sample MagnetMagnets Z-length

Extra 10 meters of each type of cable for each winding stepStraight section (mm)

Stored energy in the quarter of the dipoleSrand/CablePitch angle(degrees)=16304.8000top

(@4.2K 11.6T) =149912Joulesrequired1st2nd1010.0658middle

Strands (meters)21957807Piecesinches

f=85%Cable (meters)651646.0000

Amount of Sc (kg)12.9021.10Removable6.2832

1.067020000.81

The Texas A&M programTAMU1 (6.5 T)evaluate block-coil geometry, winding and impregnation strategies using NbTi model - tested to short sampleTAMU2 (5.2 T)single-pancake mirror magnet with ITER Nb3Sn conductor - completed, ready for testingTAMU3 (13.5 T) double-pancake model with 2.4 kA/mm2 conductor - beginning fabricationTAMU4 (14.1 T ) complete Nb3Sn dipole with 4x3 cm bore

TAMU1Model dipole to study block coil geometry: cable preparation, winding techniques, impregnation: treat exactly according to the design for Nb3Sn.

Testing of TAMU1Winding voltages during quench

Chart5

27.457.49

7.557.937

7.87.731

7.457.236

6.76.576

8.075.684

8.034.86

7.783.172

7.898.04

8.04

8.04

QH tests

Training

Ramp-Rate

Ramp #

Iq (KA)

TAMU-1 Quench History

VtapSeq

S:SideTS#Resistance300K300K65K,10AScaled300K300K300K300K300K300K300K300KRdiff vs.Tap #

L:LayerCoil---V-Tap Amp. Wiring+++17-Feb17-Feb29-Feb2-Mar2-Mar30-Aug30-Aug30-Aug1-Sep1-Sep1-Sep28-Sep28-Sep28-SepR (mohms)

SLVoltage-TapTapHypoSHVSignalSHVFinalSeqDiffDiffSeqDiffSeqDiffRatioSeqDiffDiff(meas)SeqDiffDiff(meas)RatioSHV #

##Location-ID#(m-r-c)--#Name++#Sig.ID(mohms)(mohms)(mohms)(mohms)(mohms)(mohms)(mohms)(wrt 29feb)(mohms)(mohms)(mohms)(mohms)(mohms)(mohms)28/01

Magnet Casena49Case wrt -Ref104CaseTap 49 410.08 tap 15 409.4 Tap 17 411.5mV later

B6(-) Flagna104-Lead (copper)52(-)Lead0.050.000

B6(-) Footerna52-Splice & Lead-in37Spl6-0.000.3480.61nana0.0000.620.0000.621.00

B6(-) Footer51Tap-1 jumper0.740.6200.620

Bopen38

B6L6-21-4-337C2L4 NbSnTi Splice32Spl6-0.35-0.0410.040.000.000.000.6200.040.6230.04

B6L6-21-8-132Tap-2 jumper0.780.6600.663

B6L6-21-7-131Layer 629V6

Bopenna1-6-130

B6L5-6 CT31-5-129Layer 526V50.312.8242.680.782.821.050.6602.810.6652.8251.00

B5L5+41-4-128L1-L5 splice27spl1-5

B1L1-51-3-127dupe tap-5

B5L5+41-2-126L1-L5 splice25spl1-5

B1L1-51-1-125Layer 120V1

B1L1-L2 CT mid-mag62-8-320Layer 214V23.130.001.773.600.000.003.4740.003.49000.00

B1L1-L2 CT mid-mag62-7-319dupe tap-6

B1L1-L2 CT mid-mag62-6-318dupe tap-6

T4L2+72-5-317L3-L2 splice16202.481.771.68204.701.801.07204.3621.78204.8301.821.02

T4L3-82-4-316C2L4 Pole FeedSide1524PFs204.250.890.84206.500.901.07206.1440.90206.6500.91.00Lead(KA)10

T4Openna2-3-315205.140.880.83207.400.891.07207.0400.88207.5500.921.04Flow(LL/hr)19

T3L2+72-2-314C2L3 PoleReturnSide1323PRs206.021.771.68208.291.791.07207.9211.85208.4701.780.96Rseq vs.Tap #

T3L3-82-1-313C2L3 48-Turn1223Mt207.78199.65189.55210.08201.431.06209.770201.11210.250197.750.98

T3L4L3 CT92-8-112C2L3 Outer ReturnSide1123ORs407.431.871.77411.511.901.07410.8831.89408.0002.111.12

T3L4+102-7-111C2L3 Outer FeedSide1023OFs409.302.782.64413.412.811.06412.7692.80410.1101.450.52

T3failed hipotna10412.080.00-0.00416.220.00415.5720.01411.5600.02

T3failed hipotna923spl412.080.040.04416.220.041.14415.5790.030.041411.5800.01

T3L4+102-6-146Tap-13 jumper20-0.00416.260.00415.6100.02411.5900.04

T3L4+102-5-145C2L3 Lead-in21412.120.290.20416.260.713.61415.6330.75411.6300.340.45

T3L4+102-4-18C2L3/C2L2 NbTiTi Splice02322spl412.410.00416.970.00416.3850.000.008411.9700

open2-3-1712Rmp620.931.01620.3921.02517.0400.540.53

open612PF+Re621.941.21621.4111.20517.5800.630.52

open2-2-1512PRs623.150.00622.6140.00518.21000.00

open2-1-14

(+) Footer3

(+) Footer2

(+) Footer1+Lead (copper)101+Lead825.020.02824.6150.0350.027623.020-0.05

(+) Flagna101825.020.00824.615623.020

ncnc7-3-144spare825.040.12824.6500.08622.9700.22

nc45replace shv-9825.160.01824.7250.020.024623.190-0.08

nc46replace shv-10824.740

ncnc47spare0.20825.170.713.60824.7400.70623.1100.741.05

ncnc48spare0.240.050.04825.880.051.35825.4420.110.0043623.8500.1

69spare-0.00825.930.00825.549-0.00623.9500.04

70spare0.282.782.64825.932.811.06825.5462.73623.9902.91.06

3.061.831.74828.741.851.06828.2791.84626.8901.871.01

4.90196.07186.41830.59197.891.06830.122197.65628.760201.871.02

200.971.761.671028.481.781.061027.7751.81830.6301.871.04

202.730.880.841030.260.891.061029.5810.88832.5000.951.08

203.610.870.831031.150.891.071030.4600.88833.4500.931.06

204.481.761.671032.041.771.061031.3401.77834.3801.861.05

Shorted to headernc6Shorted to header206.24197.87188.521033.81199.701.061033.110199.46836.240203.741.02

404.111.851.781233.511.871.051232.5701.871039.9802.051.10

405.962.782.641235.382.801.061234.4402.801042.0302.931.05

breakdown to header9breakdown to headernc0.00-0.001238.180.001237.2400.021044.960-0.01

breakdown to header10breakdown to headernc408.740.040.041238.180.051.281237.2600.030.0441044.950-0.08

-0.001238.230.001237.2900.031044.8700.02

-0.001238.230.001237.3200.011044.8900.19

408.780.031238.231237.3300.581045.0800.641.10

1237.9101045.720

1238.230.00

5.341

204.362

OUTER module (double-layer slipped-plane view):INNER module (double-layer fold-out view):

&[email protected] &D &T&C&A &P of &N&R&F

VtapSeq

0000

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17-Feb

29-Feb

01-Sep

28-Sep

#REF!

#REF!

#REF!

Data

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

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0

0

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0

0

0

0

0

0

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0

0

0

0

0

0

0

0

0

0

0

0

0

RdiffCalc

#REF!

#REF!

#REF!

F-M

1

1.0039090263

0

1.0213243547

1.0044642857

1.0442678774

0.9626825311

0.9832780576

1.1187698834

0.5173028898

0.4521276596

0.5299313052

0.5236907731

0

1.0545065907

1.0611050128

1.0146500271

1.0213353706

1.0354374308

1.0807736064

1.0568181818

1.0508474576

1.0214579364

1.0962566845

1.0464285714

1.1034482759

V-tap Sequence

R/R0

Resistance Ratio (300K)

RRR

Tamu1FieldD(mm)ConductorLayersIreal/IreqdB/dI (T/KA)L(m)

Summary1-DipoleNbTi31.250.81880.5SteadyTransient

RampDateTimeFileTbathdI/dt(req)IqdI/dtdI/dt)dBc/dtBcalcBhallStart-1t1Start-2t2Start-3t3MIITSTimeSpeeddV/dt(Max)N(fm)RemarksRampIq/IssdB/dtdB/dt

#(ddmmm)(hhmm)Name(K)(A/s)(KA)(A/s)RatioTesla/minTeslaTeslaLoc(ms)Loc(ms)Loc(ms)miits(ms)(m/s)(V/s)>100V/sRemarks#(%)(T/min)(T/min)

11-Dec16:56HTR2094.302.00000.000.001.64na1

21-DecQ014.3107.45012.51.250.616.10na2

31-DecQ024.3107.55012.51.250.616.18naVbal-mac26.223Mt52.60.42Heater triggered30.96

41-DecQ034.3107.80012.51.250.616.39na1Mt(I&O)49.213OFs501Ramp543.47PS problems40.99

51-DecQ044.3107.45012.51.250.616.10na1Mt(I&O)48.413PRs5013ORs52.42.44", Est: L = 2mH50.94

61-DecQ054.3106.70012.51.250.615.49na23Mt49.423OFs51.423ORs56.241st Training quench60.850.61

71-DecQ064.3108.07012.51.250.616.611Mt(I&O)4913ORs5013PRs50.44Inner = Outer71.020.61

81-DecQ074.3108.03012.51.250.616.5723PRs48.623Mt4923OFs51.44Inner starts late but takes over81.020.61

9Q084.3107.78012.51.250.616.371Mt(I&O)49.413OFs50.213PRs58.63.9890.990.61

10Q094.3107.89012.51.250.616.461Mt(I&O)49.213OFs50.213PRs61.84101.000.61

11Q104.3207.490251.251.236.131&2Mt(I&O)110.951.23

12Q114.3407.937501.252.466.501&2Mt(I&O)121.012.46

13Q124.3807.7311001.254.916.331&2Mt(I&O)130.984.91

1431-Dec9:19Q134.31607.2362001.259.835.922Mt(I&O)1Mt(I&O)N+1.5140.009.83

1531-Dec9:31Q144.33206.5764001.2519.655.381&2Mt(I&O)C1 >> C2150.8319.65

1631-Dec9:45Q154.36405.6848001.2539.304.651&2Mt(I&O)C2 >> C1160.7239.30

1731-Dec9:56Q164.310004.8612501.2561.413.982Mt(I&O)170.0061.41

1831-Dec10:13Q174.320003.17225001.25122.822.602Mt(I&O)180.00122.82

1931-Dec10:32Q184.358.046.251.250.316.586.551&2Mt(I&O)190.000.31

2031-Dec11:51Q194.308.0400.000.002Mt(I&O)200.000.00

2131-Dec12:31Q204.308.0400.000.009.341Mt(I&O)211.020.00

TAMU-1 Training

D20 4K Ramp-rate data

dB/dtBB/Bss

(T/min)(T)ratio

Splice Data0.2012.7041.00

ImagSpl13-14Spl27-28dR/dI13-14dR/dI27-280.5112.7461.00

(KA)(mV)(mV)(nOhms)(nOhms)1.2212.4260.98

0.115-0.00106-0.011411.0212.6250.99

1.006-0.00107-0.01205-0.010.721.5212.2460.96

1.998-0.00077-0.012920.300.882.2411.6060.91

2.997-0.00039-0.012880.38-0.042.4410.8880.86

4.007-0.00013-0.01310.260.222.7410.7330.84

5.003-0.00002-0.012690.11-0.413.0510.1630.80

5.0030.00035-0.011330.000.00After cable change(27-28)3.259.5830.75

6.0050.00044-0.01400.092.693.459.1720.72

7.0010.00052-0.014910.080.883.569.3070.73

3.766.8440.54

3.863.3620.26

4.063.1980.25

5.082.8960.23

6.102.7920.22

8.132.6890.21

10.162.6800.21

20.322.6460.21

LHC Spec.

0.42700

0.427131

Coil-1

Coil-3

Coil-2

+

-

&C&A

&[email protected] &D &T&C&P of &N&R&F

RRR

000

00

00

00

00

00

00

00

00

0

0

0

&[email protected] &D&T&C &P&R&F

System

Training

Ramp-Rate

Ramp #

Iq (KA)


Short Sample

0

0

0

0

0

0

0

0

0


T- Ramp #

Iq (KA)

TAMU-1 Training

HallCalib

00

00

00

00

00

00

00

00

00

0

0

0

0


Training

Ramp-Rate

Ramp-Rate (A/s)

Iq (KA)

TAMU-1 Ramp-Rate

000

00

00

00

00

00

00

00

00

0

0

0

0

0

0


System

Training

Ramp-Rate

Ramp #

B(T)


00

00

00

00

00

0

0

0

0

0

0

0

0


Training

Ramp-Rate

dB/dt (T/min)

Bq/Bss

RT-1 Ramp-Rate

0

0

0

0

0

0

0

0

0


T- Ramp #

Bq (T)

TAMU-1 Training

0

0

0

0

0

0

0

0

0


T- Ramp #

Bq/Bmax

RT-1 Training

0

0

0

0

0

0

0

0

0

11.8T

12.2T


RT-1 Training

RT-1 Ramp-Rate

D20 Ramp-Rate

RT-1 Transient

LHC Spec.

dB/dt (T/min)

Bq/Bss

Ramp-Rate Dependence

0

0

0

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LHC

dI/dt (A/s)

quench current (kA)

0

0

0

0

0

0

0

0

0

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0

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0

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0

dI/dt (A/s)

quench current (kA)

Fast-Moption Comparison

Fast-Motions

Plateau

08.33

158.33

RD201

N (#)Imag (KA)C1-C2C2: O-IC1: O-I

#KAV/sV/sV/s

15.678-540I,o,I,I

27.200-130I,o

37.770-700I

RD202


#KAV/sV/sV/s

14.74-100I,o0

25.7-250b,I0

RD203


#KAV/sV/sV/s

13.84-500o,I

26.03-420bv

36.56980I

46.731050I,o

56.78850o,i

66.7831100o,I,o

76.788280I

87.045720o,I

97.52590o,I,I

107.75-620o,I,i

117.83555+60, -120

RD204


#KAV/sV/sV/s

14.36-480-300

25.39-580+40, -800

35.72-520+40, -5070

46.087-950-1000

56.092-450-50-80

66.16-1100-80-10

76.48-100-100

86.92-100-200

97.00-850+20, -500

107.39-300-300

117.45-870+60, -1200

127.54-500+10, -700

137.62-510-1000

147.76-490-88

RD205

08.33

&[email protected] &D &T&C&P of &N&R&F.&A

000000

00000

000

00

00

00

00

00

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Plateau

RD201

RD202

RD203

RD204

RD205

#REF!

#REF!

#REF!

Data Source

v3021316.csvCu/NonCuConductorCopperR(300K)R(20K)R(17K)RRR(20K)RRR(17K)Ratio(17/20)

Cool-down(ratio)Coil-layer% of total(mOhms)(mOhms)(mOhms)(ratio)(ratio)(ratio)

146.50.261790.000.00

241.20.221870.000.00

339.70.201990.00.00

434.80.181930.00.00

539.80.182210.00.00

635.00.152330.00.00

Ratio(T/B)0.0000.9541.0170.0000.9140.0000.000


Field (T)26*Istrand(KA)Icable(KA)Icalc(KA)Iq(KA)

11.569.945

10.0015.8

11.8010.157

12.0110.339

12.2210.514

11.0012.9

12.0010.8511.0

9.648.296

14.007.2

15.006.012.9

10.008.6

0000

0000

0000

0000

000

000

000

000

000

000

Load Line

Strand X 26

Cable

Training Quenches

26*Istrand(KA)

Icable(KA)

Icalc(KA)

Iq(KA)

B (Tesla)

I (kA)

Cable-Strand-Magnet Performance

0000

0000

000

000

00

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00

Training Quenches

Cable

26-Strand

Load Line

26*Istrand(KA)

Icable(KA)

Iq(KA)

Load Line

B (Tesla)

I (kA)

Cubic fit worksheet

TotalI(A)

B(T)V(mV@100mA)YCubicY5.00E-03

HG09242V(mV@100mA)Ax^3+Bx^2+Cx+DA(X-D)^3+B(X-D)^2+C(X-D)D=0 coeffs

-15-116Cubic FitscontributionV0

00-10-78-5.01700E-08A-5.017E-08-0.40136-3.947E-06-2.410E-07

0.54.08-7.5-57.5-9.32400E-05B-9.330E-05-3.7-4.875E-04-1.692E-04

18.17-5-381.19500E-01C1.194E-0123.91.157E-011.254E-01

1.512.25-3-24.37-4.34700E-02D\adj0.400.002000.000E+000.000E+00

216.3-2.5-20.3427.55X7.55

2.520.388-2-16.300.85Y0.85

324.4-1.5-12.23

543-1-8.153

7.566-0.5-4.075

109300

0.54.08

18.17

1.512.25

216.3

2.520.388

324.4

544

7.566

1093


0

0

0

0

0

0

0

0

0

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0

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V(mV@100mA)

HG09242

Curve-Fit

MBD04CA79E5.doc

V-Tap

Splice

Thermometer

V-Tap

Splice

Thermometer

[email protected] 0/0/0000 0:00 AM1 of 1~WRO3717

MBD04CA79E4.doc

V-Tap

Splice

Splice

Thermometer

Thermometer

[email protected] 0/0/0000 0:00 AM1 of 1~WRO0683

AC lossesTAMU1 is the first fully impregnated NbTi dipole made in modern times. It operated to short sample without training and exhibits good AC performance.This result demonstrates that the helium access thought essential for NbTi stability is not necessary, provided that stress is managed so as to prevent conductor motion and friction heat.1 T/s1.5 T/s

Chart2

12.57.45

12.57.55

12.57.8

12.57.45

12.56.7

12.58.07

12.58.03

12.57.78

12.57.89

7.4925

7.93750

7.731100

7.236200

6.576400

5.684800

4.861250

3.1722500

8.046.25

ramp-rate studies

training

ramp rate (A/s)

quench current (kA)

Sheet4

SUMMARY OUTPUT

Regression Statistics

Multiple R0.9763586015

R Square0.9532761187

Adjusted R Square0.9454888051

Standard Error0.1352950919

Observations8

ANOVA

dfSSMSFSignificance F

Regression12.24075892862.2407589286122.4139893340.0000324509

Residual60.10982857140.0183047619

Total72.3505875

CoefficientsStandard Errort StatP-valueLower 95%Upper 95%Lower 95.0%Upper 95.0%

Intercept-1.28285714290.1143452226-11.21915820930.0000299518-1.5626500278-1.0030642579-1.5626500278-1.0030642579

X Variable 10.27857142860.025177989411.06408556250.00003245090.2169630630.34017979420.2169630630.3401797942

Sheet1

Joint resistance

Current (kA)Voltage (mV)Resistance

splice 1splice 2splice 1

0.115-1.06-11.40.28nano-ohm

1-1.07-12.1

2-0.77-12.9

3-0.39-12.9

4-0.13-13.1

5-0.02-12.7

50.35-11.3

60.44-14

70.52-14.9

Training

17450

27650

37800

47450

56700

68050

78030

87780

98020

Sheet1

0

0

0

0

0

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0

0

0.28 nW

bbbbbbbb

voltage (microvolts)

Current (kA)

Voltage (mV)

Splice resistance measurement

Sheet2

0

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0

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0

quench #

quench current (A)

Training of TAMU1

Sheet3

dI/dtIq

12.57.45

12.57.55

12.57.8

12.57.45

12.56.7

12.58.07

12.58.03

12.57.78

12.57.89

257.49

507.937

1007.731

2007.236

4006.576

8005.684bb

12504.86

25003.172

6.258.04

Sheet3

00

00

00

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00

ramp-rate studies

training

ramp rate (A/s)

quench current (kA)

TAMU2: our entry into Nb3Sn technologyTAMU2: 1 single-pancake windingmirror geometry, ITER superconductor5.6 T short-sample bore field

Coil windingTi mandrel to preserve preload through cooldown.Inconel ribs, laminar springs transfer stress between windings.

Reaction bake @ 650 CArgon atmosphere purge manifolded throughout coil.Same furnace can bake 875 C in O2 purge for Bi-2212 and maintain separate purges of Ar in Nb3Sn, O2 in Bi-2212 windings. We can react a 3 m long dipole in this furnace.

Splice leads Nb3Sn to NbTiLead is supported in rigid frame anchored into winding superstructure, spliced to a pair of NbTi leads.

Preload, weld pancake subassemblyPreload side bars and end shoes. Weld cover skin to stabilize coil subassembly.Note: For stress management, we do not apply large preload, only ~3 MPa, just enough to remove soft modulus from coil. After impreg and dipole assembly, we will apply larger preload to the structure to provide stiff walls.

Vacuum impregnationHorizontal orientation (with tilt), multiple flow paths assure full impregnationWe can impregnate a 3 m long dipole in this retort!

Bladder preloadEntire dipole heated to 80 C.Bladders preloaded to 2,000 psi using hand pumps.Pressure sustained while magnet is cooled using water jacket.

TAMU3: going to high field and testing stress managementTAMU3: 2 single-pancake windings3 kA/mm2 superconductor13.5 T short-sample bore fieldTAMU4: 2 single-pancakes, one double-pancake3 kA/mm2 superconductor14.1 T short-sample bore field

Magnets are getting more efficient!NbTiNb3SnBi-2212

Chart2

2.51942428050

6.332003143792

18.7500641106297.4390625

23.617064019410

38.950778904926.40625

44.1

quadratic B dependence

RHIC (7 cm)

Tevatron (5 cm)

Pipe (2 cm)

SSC (5 cm)

LHC (7 cm)

microbore (3x2 cm)

TAMU4 (3 cm)

LHC Tripler(6x4 cm)

NbTi

Nb3Sn/NbTi


Bi2212

field strength (T)

coil area (cm2)

Sheet1

Parameters of various superconducting magnets

magnetpeak fieldaperturecoil currentstored energyampturnsconductor areaoverallnotes"COST"peak fieldtunnel cost/TeVtunnel + sc

(T)radius (cm)(kA)(MJ/m)(MA)(cm2)cold mass$100/kg NbTi, $200/kg NbSn, $1000/kg BSCCO(T)1000$/m

NbTiNb3SnBi-2212mm0.000

Superferric22.005.000.062.5242.522.0020.734511513725

RHIC34.005.000.040.166.3331066.333.457.439062512.020006674618

Tevatron43.804.500.080.5018.753801618.754.001010.367255756826

SSC72.506.500.070.5923.624201223.626.5026.406256.379849696518

LHC82.8011.760.260.8738.955501538.958.4044.14.936788455620

tripler123.0010.000.850.7618.4616.362401416.3612.003.455751918918

LHC tripler2428.00501.7278759595

microbore119.003.6376335989

T12122.5012.3013.001113.0012.003.455751918914

T14152.0010.0038.001738.0015.002.764601535220

T20202.0012.002.863.0530.1422.08jBi=1000 A/cm22852.2220.002.073451151430

D20142.506.720.950.8413.50113.906253.07177948353

T16161.009.201.732.3279.8458016.001602.59181393923

TAMU414.0029.0012.00212.96207307343

Sheet1

0000

000

000

00

00

0


RHIC (7 cm)

Tevatron (5 cm)

Pipe (2 cm)

SSC (5 cm)

LHC (7 cm)

microbore (3x2 cm)

TAMU4 (3 cm)

LHC Tripler(6x4 cm)

NbTi

Nb3Sn/NbTi


Bi2212

field strength (T)

coil area (cm2)

Sheet2

0000

0

0

0

0

NbTi

Nb3Sn/NbTi

Nb3Sn

Bi-2212/Nb3Sn

magnetic field (T)

coil cost ($M/TeV)

Sheet3

000

000

000

000

superconductor

tunnel

total

field strength (T)

cost ($M/TeV)

Inject to LHC from SuperSPSFor luminosity upgrade of LHC, one option is to replace the SPS and PS with a rapid-cycling superconducting injector chain.1 TeV in SPS tunnel 1.25 T in hybrid dipole: flux plate is unsaturated, suppression of snap-back multipoles at injection.SuperSPS needs 6 T field, ~10 s cycle time for filling Tripler >1 T/s ramp rate

Again block-coil geometry is optimum!In block-coil dipole, cables are oriented vertically:

Result: minimum induced current loop, minimum AC losses

In cos dipole, cables are oriented on an azimuthal arch:

Result: maximum induced current loop, maximum AC losses

Preliminary design for Super-SPS dipole6 T short-sample field (to allow for AC loss degradation)LHC NbTi strand (wider cable to optimize geometry, minimize inductance)We are modeling AC losses, expect to be low.Flux plate suppresses multipoles from persistent currents, AC-induced currents(flux plate must be laminated)

Documents

Recent Developments in Nb 3 Sn Dipole Technology at Texas A&M Peter McIntyre Dept. of Physics Texas A&M University [email protected]