Update on the potential of Bi-2212 for high field magnet use · Nexans was the benchmark producer...

April 10, 2018 1

D.C. LarbalestierWith major collaborators Eric Hellstrom, Jianyi Jiang, Fumitake Kametani and Ulf Trociewitz at

the NHMFL, Tengming Shen at LBNL, multiple PhD students and staff and many industrial

partners noted on the next slide

Update on the potential of Bi-2212 for high field magnet use

This work is supported by the UD Department of Energy for Conductor Development underGrant DE-SC0010421, by the National Science Foundation under NSF/DMR-1644779, by a grant from the National Institute of

Health under 1 R21 GM111302-01, by the state of Florida, and is also amplified by the U.S. Magnet Development Program (MDP).

1

April 10, 2018 22David Larbalestier FCC Workshop Amsterdam, April 9-14, 2018

2212 conductor development has been a Collaboratorium

E. S. Bosque, M. Brown**, D. S. Davis**, C. L.

English, G. Bradford, I. S. Hossain**, Jianyi

Jiang*, Y. Kim, E. Miller, G. E. Miller, Y. Oz**, J.

Lu, F. Kametani*, U. P. Trociewitz*, E. E.

Hellstrom*, and D. C. Larbalestier*

*PIs of the DOE-OHEP supported conductor

effort and the internal NSF solenoid-driven

development

**PhD students

At ASC-NHMFL-FSU Our external

collaboratorsTengming Shen (LBNL)

Yibing Huang and Hanping Miao (B-OST)

Marvis White, Riley Nesbit, Aixia Xu and

Andrew Hunt (nGimat)

Alex Otto (SMS)

Suvankar Sengupta and Rao Revur

(MetaMateria)

An integrated effort by DOE-OHEP, SBIR

program, NSF through NHMFL and some

key early support by CERN through

EUCARD2 – and now USMDP

April 10, 2018 3

Outline of the talk

• Conductor– Good powder– Good wires

• Twisted with low hysteretic loss made in single pieces with 1-2 km length at 1 mm and 0.8 mm diameter

• Coils– Reliable HT under 50 bar is now routine– Double insulation scheme valid on 1 km scale– We can reinforce conductor in winding pack to support >300 MPa in

tension – higher stress at 0.4% strain in view– A new reaction chamber (25 cm dia./1 m long) and magnet test bed (14

T/160 mm bore) is under active MDP discussion

David Larbalestier FCC Workshop Amsterdam, April 9-14, 2018

April 10, 2018 4

Key messages• No one is going to use any HTS

conductor if they can use Nb-Ti or Nb3Sn………..

• All HTS conductors are 7-15 times the (volumetric cost) of Nb3Sn.

• High Field or High Temperature use are key

Magnet builders much prefer round, twisted, isotropic

conductors with high conductivity normal metal around the

filaments

This is exactly what Bi-2212 offers – in many architectures

with Jc well exceeding Nb3Sn from about 12 T up

Nb-Ti

Nb3Sn

Bi-2212


April 10, 2018 5

Two small US companies now making powder

MetaMateria

Use co-precipitation

nGimat

Use spray combustion to form 2212

Replicating the Nexans 521 composition

New 2212 powders are better than the best of Nexans*

No need for grinding agglomerated bulks

Particle size and uniformity better than NexansImportant contribution of CERN in context of EUCARD-2 for enabling Nexans final powder

production from which we learned much due to care of Mark Rikel in its manufacture


April 10, 2018 6

Nexans was the benchmark producer for more than 10 yrs

JC(4.2K, 15T) = 4200 A/mm2

JE(4.2K, 15T) = 825 A/mm2

Still some small hard particles, but

less impact on filament quality in

drawn wires (filament merging).

Note for FCC magnet builders: Jc far exceeds the FCC specification (~1850 A/mm2 at 15 T) and with only

20% superconductor cross-section, very high conductivity Ag without any diffusion barrier that can break

during cabling and then degrade the RRR

Data by Bonura and

Senatore on our OP wires

RRR > 100


April 10, 2018 7

Recent nGimat and MetaMateria powders established a new benchmark (2017) in standard B-OST wires

Powder LXB-43

Some Bi-2201 (white), AEC-14/24

(black), and Cu-free (next to 2201)

Powder LXB-52

No Cu-free and Bi-2201, with

large AEC-14/24 particlesv

New level of phase and particle size control with “simpler” and cheaper processes


Jianyi Jiang

April 10, 2018 8

New record Jc for 0.8 mm wire from nGimat LXB 5270% increase in Jc over the last and best Nexans lot 87

2 3 4 5 6 7 8 9 10 11 12 13 14 15 163000

4000

5000

6000

7000

8000

9000

10000

11000

Nexans lot 87

nGimat LXB-52

Nexans lot 87

50 bar OP-HT

JC,

A/m

m2

B, T

nGimat LXB-52

IC(4.2K, 15T) = 658 A, JE(4.2K, 15T) = 1365A/mm2,

JC(4.2K, 15T) = 6860 A/mm2

Ic (0.8 mm wire) = 660 A at 15 T and 475 A at 30 T

with only 19% superconductor in the wire

Most recent optimized HT

June 2017 high field data

2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32

400

600

800

1000 pmm170123-4

pmm170123-10

pmm170123-3

Critica

l C

urr

en

t, I

C [A

]

Field, B [T]

Reacted state

sub-bundles

(Some

interfilament

connections

but with low

hysteretic loss)


Jianyi Jiang

April 10, 2018 9

Round wire Jc goodness plot

102

103

104

0 5 10 15 20 25 30 35

Wh

ole

Wir

e C

riti

cal C

urr

en

t D

en

sity

(A/m

m²,

4.2

K)

Applied Magnetic Field (T)

Bi-2212: 50 bar OP

Nb₃Sn: Internal Sn RRP®

Nb-Ti: LHC 1.9 K

Nb-Ti: LHC 4.2 K

Nb-Ti: High Field MRI 4.22 K

2212

Nb3Sn: High Jc

Maximal Je at 1.9 K for entire LHC NbTi

strand production (CERN-T. Boutboul '07). Reducing the temperature from 4.2 K

produces a ~3 T shift in Je for Nb-Ti

Compiled from

ASC'02 and ICMC'03 papers

(J. Parrell OI-ST)

Nb-Ti

4.2 K LHC insertion

quadrupole strand (Boutboul et al. 2006)

4.22 K High Field

MRI strand(Luvata)

August 30th 2017

Nb-Ti1.9 K

37×18 filament B-OST strand with NHMFL

50 bar Over-Pressure HT. J. J. Jiang et al.

2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32

0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

1.5

1.6

1.7

pmm170123-4

pmm170123-10

pmm170123-3

I C / I

C(1

5 T

)

Field, B [T]

Normalized IC at (15 T)

Jc(H) falls off only slowly because Hirr >> 50 T: Jc (20T) is 83% and Jc (30T) 72% of Jc (15 T)

Michael Brown

Peter Lee

Best measured is 970 A/mm2 at 30 T


April 10, 2018 10

High Field Data shows excellent Jc(H) scaling out to at least 31 T –connectivity is the dominant multiplier for Jc(H)

Michael Brown (PhD 2018)-2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34

200

400

600

800

1000 pmm170123-4

pmm170123-10

pmm170123-3

pmm160524-2

pmm160913-1

pmm160913-2

pmm160913-3

Critica

l C

urr

en

t, I

C [A

]

Field, B [T]

Fp (4K)

Field [T]

10 K/ 37 T15 K/ 17 T20 K/ 9 T

Viewed globally, wires of last few years with different powders have large range of JcNormalized Jc(H) relations are all very similar

Fpmax does not peak at 31 T and 4 K


April 10, 2018 11

Twisting reduces coupling losses and does not degrade Jc

Yavuz Oz et al., ICMC-2017

27x7

38x18

Yavuz Oz et al., ICMC-2017

Hysteretic

losses are

comparable to

ITER Nb3Sn

wires

Jc is much

higher Physically uncoupled filaments show greater benefits from twisting

Samples Qs kJ/m3 QSC MJ/m3

Bi-2212 450-600 2.00-3.00

Nb3Sn 200-500 1.20-2.30

Bi-2223 1500 5.00

REBCO 3400 320.00


April 10, 2018 12

50 bar Over Pressure (OP) removes filament size dependent properties(1.5-1.0 mm wire dia.) – and widens the HT window

OP removes filament size dependent

properties

(1.5-1.0 mm wire dia.) 1.0 mm/9.3 mm wire

Densified 1.4 mm wire,

12.9 µm filament dia.

Jiang et al., IEEE Trans. Appl. Supercond., 27, 4, 6400104 (2017) )

9 10 11 12 13 143000

3500

4000

4500

5000

5500

6000

JC(4.2 K, 5 T)

JC(4

.2 K

, 5

T),

A/m

m2

Densified Filament Diameter (mm)

1.0 1.1 1.2 1.3 1.4 1.5 mm

5

10

15

20

25

30

35

40

45

50

55

n value

n V

alu

e

Very similar filament size

distribution

Nexans powder, 2014


April 10, 2018 13

Getting the conductor into magnets

• Must react coil at almost 900C, not just short samples – and at 20-100 bar overpressure (OP) – we use 50 bar now (1 bar O2, balance Ar), almost exclusively

• Coil insulation must withstand reaction after winding

• Strengthening methods must be available for low E (70 GPa) and low s0.2 (~100 MPa) and be applicable to coil manufacture

Overpressure increases Jc by 5-8 times and prevents internal pressure leakage


DCL et al, Nature Mat 2014

April 10, 2018 14

Bi-2212 Conductor Strengthening is mimicking 2223


425 MPa at 0.4% strain versus 118 MPa for 2212/Ag~3.5 fold benefit with 33% strip area (similar to SEI 2223 NX).

FSU Measurements on SMS tapes given OPHT at FSU

• Low aspect ratio applied to preserve electro-magnetic isotropy of wire

• Shown here is a wire bonded with reinforcement tape made by Solid Materials Solutions (SMS, Alex Otto)

• Work on reinforced conductor in coils is ongoing – as also is round wire strengthening

Alex Otto (SMS) and Michael Brown (FSU)

April 10, 2018 15

Insulation for 2212: hybrid TiO2 and mullite fiber


• Dip coating process with TiO2 particles dispersed in a polymer

• Polymer burns off leaving strong ceramic layer

NHMFL Insulation line, Jun Lu, J. Levitan

• >1 km lengths now being coated reliably• Added alumino-silicate braid to improve

stand-off and winding pack integrity

Alumino-silicate braid

TiO2

coating

• Tests at LBNL of their coated and braided race-track coils have also shown higher leak resistance along with an improvement of transport properties

April 10, 2018 16

2212 test coils: thick (pups) and large diameter (Riky) for high stress

About 1 km of conductor each!

• We build Coils of various sizes from small bobbins to fully instrumented larger coils for in-field testing applying analysis lead design

• Models coils are confidence builders for larger high-field coils like Platypus and beyond (testing new concepts, models, manufacturing procedures)

(All to scale)cm70

60

50

40

30

20

10

8.7 cm

10.5 cm

13.3 cm

8.7 cm


Youngjae Kim, Ernesto Bosque and Ulf Trociewitz

April 10, 2018 17

Modeling Coil Behavior


LTS Outsert at 8 T, HTS (Pup) coil at 4 T

(400 A)

Source:Jphi

. Bz. R [MPa]

AzimuthalStress Map [MPa]

AzimuthalPercent Strain

[%]

Goals: Understand and control performance limits of our 2212 coils • Model coils with conductor resolution• Compare with experiments

Riky concept: test coils with large bore size to generate high hoop stresses, TiO2 and braid insulated wire, varying reinforcement

Pup concept: test coils with same ID and OD as Platypus to allow observation of strain gradients across winding pack, TiO2 and braid insulated wire, varying reinforcement

Pup coil in 8 T outsert

Ernesto Bosque, Youngjae Kim,and Ulf Trociewitz

April 10, 2018 18

RIKY 3 test coil


• FEA modeling is predicting coil performance well: 348 A predicted for onset of damage (Bjoerstad data confirmed by us (Michael Brown)

• The first trip was observed at 350 A compared to expected of 348 A!

• Very clearly not an Ic transition but rather a strain induced trip

• In no-reinforced condition the outer layer would have experienced a stress of ~300 MPa: reinforcement is effective

• Showed saturation of Ic retention on subsequent quenches

• Below onset of thermal runaway the coil could be load-cycled many times

Predicted peak strain expected for given Riky-3 operating currents are shown as blue line plotted against Ic/Ic0 retention curve based on data by C. Scheuerlein*, CERN

*R. Bjoerstad, C. Scheuerlein, M. Rikel et al., Supercond. Sci. Technol. 28 (2015) 062002

Predicted critical strain trip at 350 A:

Youngjae Kim, Ernesto Bosque and Ulf Trociewitz

April 10, 2018 19

A new HTS test bed


Platypus coil

300 mm

• Is ideal test bed to explore performance limits of HTS inserts for improving performance predictions

• Magnet provides sufficient space to run 2212, 2223 or REBCO coils up to 30 T

14 T Magnet by Cryogenic LTD to be commissioned soon at ASC:• Magnet bore 161 mm• 128 ppm homogeneity (1 cm DSV)

without compensators or shims

Lamar English, Ernesto Bosque, Eric Hellstrom and Ulf Trociewitz

April 10, 2018 20

• First-of-its-kind pressurized 6-zone furnace built by Deltech

• Currently largest OP furnace available for Bi-2212 heat treatment

• Design parameters: 900 °C, 100 atm total pressure, 500 mm hot zone – currently use 50 atm and the hot zone is ~430 mm (130 mm dia.)

• This furnace required extensive in-house engineering to make it a robust, reliable equipment

• Successful heat treatment of many coils

Our High Pressure Furnace is the Work Horse for Bi-2212 Coil Heat Treatment

Outer wall dia: 324 mmWorking Hot Zone dia: 130 mmWorking Hot Zone height: 430 mm


April 10, 2018 21

Hot Zone is Very Uniform Even with Large Thermal Mass – Platypus-II Dummy Coil

Zone1.5SS|707A|988A/mm^2



Zone1.5 – 707 A, 988 A/mm2

Zone2.5 – 697 A, 973 A/mm2

Zone3.0 – 697 A, 973 A/mm2

Placement and Ic

,Jc values of short samples

Stack of metal rings to simulated thermal mass of Platypus –II coil

Thermocouples monitoring locations on dummy

Dummy coil with three 18 layer, 3 turn test sections to verify calibration and OPHT procedure

21

Ernesto Bosque

April 10, 2018 22

OPHT Yields Uniform Transport from Top to Bottom and from Inside to Outside

988 973 972

721690 684

677 676 661

500

600

700

800

900

1000

1100

1 2 3 4

J_e[A/m

m^2]

DeltechFurnaceZone#

PYP-IIDummyShortSampleJ_e

TestIDJ_e

TestODJ_e

WiresPYP-II dummy: Pmm 140606SS: Pmm 160301

ID:

OD:

SS:




Zone 1.5 – 707 A, 988 A/mm2

Zone 2.5 – 697 A, 973 A/mm2

Zone 3.0 – 697 A, 973 A/mm2

Placement and Ic ,Jc values of short samples

Four important outcomes:• Coils performed consistently throughout the dummy stack• No oxygen deficiency in inner layers• Bottom windings survived compressive force of (simulated)

winding pack• We can handle the thermal mass and weight of Platypus-II

22

Ernesto Bosque and Lamar English

April 10, 2018 2323

LBNL HTS (2212) subscale magnet program topped with new RC-05 results

LBNL 17-strand Rutherford cable

Mullite braided insulation

Subscale coils allow fast-turnaround test of cable and magnet-relevant technologies.

23

LBNL RC-1,2,3,5 in FSU OP furnace

2212

RC5 – 3.4 T, Jcable = 740 A/mm2, Jwire = 940 A/mm2.Made possible by OPHT at FSU, wire by Bruker OST, and powder by nGimat.

Tengming Shen, Ernesto Bosque

and Lamar English

April 10, 2018 24

RC5 – E-J characteristics defined with a stair-case I(t) run. Many resistive, easy to detect signals revealed before the quench

(global superconducting transition driven by continuous joule heating)

100 200 300 400 500 600

1E-7

1E-6

1E-5

1E-4

1E-3

Co

il v

olt

ag

es

(V

)

Time (sec)

Vete

VL1

VL2

100 200 300 400 500 600

2000

4000

6000

8000S

hu

nt

cu

rre

nt

(A)

Time (sec)

Current (A)

100 200 300 400 500 600

0

50

100

150

200

250

300

350

400

Tu

rn v

olt

ag

es (m

V)

Time (sec)

L1-T1'

L1-T2'

L1-T3'

L1-T4'

L1-T5'

L1-T6'

Ramp-turn

L2-T6'

L2-T5'

L2-T4'

L2-T3'

L2-T2'

L1-T1 having voltage rises due to heating from splices.

Quench

RC5

5500 6000 6500 7000 7500 8000

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

L1-T6'

ramp turn

Fit, Ic=8282 A (1.0 mV/cm), n=28

Ele

ctr

ic f

ield

(m

V/c

m)

Current (A)

7925 A (DCCT), 180 s no quench.

8128 A (DCCT), a few sec quench.


Tengming Shen LBNL

April 10, 2018 25

The global superconducting transition - Multiple turns turning normal makes possible easy quench detection.

500 502 504 506 508 510 512 514 516 518 520

-10

0

10

20

30

40

50

60

70

80

90

100

Tu

rn v

olt

ag

es

(m

V)

Time (sec)

L2-T6'

L2-T5'

L2-T4'

L2-T3'

L2-T2'

L1-T1'

L1-T2'

L1-T3'

L1-T4'

L1-T5'

Ramp-turn

L1-T6'

500 502 504 506 508 510 512 514 516 518 520

1E-6

1E-5

1E-4

1E-3

Co

il v

olt

ag

es

(V

)

Time (sec)

Vete

VL1

VL2

Quench

RC5


Tengming Shen LBNL

April 10, 2018 26

Plans for a Larger OP Furnace

• Current furnace:– Working Hot Zone height: 430 mm– Working Hot Zone dia: 130 mm

• Due to a demand of heat treating larger coils (race-track, CCT coils with LBNL, and solenoids) we started planning for a bigger OP furnace

• Pressure range will be 50 bar• New furnace specs:

– 1 m working hot zone height (900oC)– 266 mm working dia.

• Major components to be sourced through commercial suppliers, assembly at the Lab, Labviewcontrolled

26

1 m long homogeneous zone


April 10, 2018 2727David Larbalestier FCC Workshop Amsterdam, April 9-14, 2018

The conductor technology is mature at present scale

Single 10 kg piece lengths: 2.4 km at 0.8 mm, ~1 km at 1 mm

Twisted, multifilament, isotropic, low loss conductor with high RRR (> 100) and no need for diffusion barrier

Insulation technology for single wires is good

Reaction under 50 bar to 13 cm dia. x 40 cm length

Strain control at ~300 MPa demonstrated in coils with strengthened wires at >400 MPa

We have successfully replaced the classical powder producer Nexans with two new suppliers, nGimat and MetaMateria

Present status: 2212

April 10, 2018 28

Thank You!

28

Update on the potential of Bi-2212 for high field magnet use · Nexans was the benchmark producer...

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Transcript of Update on the potential of Bi-2212 for high field magnet use · Nexans was the benchmark producer...