Introduction of FUJIKURA RE-based HTS Wire...Sample : Ic = 387A/10mm-wide@77K, self-field (Superconducting layer thickness: 2.2μm) * This work includes some data measured at High

Introduction of FUJIKURA RE-based HTS Wire

Superconductor Business Development Division

New Business Development Center

Fujikura Ltd.

Rev. FEB2019

Characteristics of Superconductivity

2

Superconductivity

An electrical resistivity becomes exactly zero

which occurs in certain materials below a characteristic temperature.

• Critical Current --- Maximum current at superconducting state

• Critical Temperature --- Maximum temperature at superconducting state

• Critical Field --- Maximum magnetic field at superconducting state

Three Critical Points of Superconductivity

Superconductor

Copper

Temperature

Resistance

Superconductivity

0

Normal Conductivity

Critical Temperature

Temperature

Current

Field

Critical Current

Superconductivity

Critical Temperature

Critical Field

Zero Resistance ⇒ No Heat, No Loss

Current

Copper Wire

Superconducting Wire

Current

Resistance ⇒ Heat, Loss

Historical Discovery of Superconductor

3

Low Temperature Superconductors

(Metal-based)

High Temperature Superconductors

(Copper Oxide-Based)

• Indicate superconductivity above LN2 temperature

• Verification stage for practical use

Bismuth (Bi) - - - the 1st generation (1G)

Yttrium (Y) - - - the 2nd generation (2G)

• Require cooling below LHe temperature

• Practical use in conventional superconducting applications

10

50

100

Tc (K)

1920 2000 1980 1960 1940 year

Nb

NbTi

Nb3Sn

Nb3Ge

LaBaCuO

YBaCuO BiSrCaCuO

TlBaCaCuO

HgBaCaCuO

NbN

MgB2

Copper Oxide (HTS)

Metal

LN2 77

Pb

Hg

1G HTS

2G HTS

LHe 4.2

Discovery of Superconductivity

(1911)

Cri

tica

l Cu

rren

t (I

c) x

Len

gth

(L)

(Am

)

Fiscal year

100

101

102

103

104

105

106

1992 1996 2000 2004 2008 2012

124Ax105m

(2004)

88Ax217m

(2005)

Historical Development of HTS at Fujikura

4

The Word’s First

Solenoid Magnet

The World’s First

Cryo-cooled Magnet

The World’s

First 200m

2004 LN2 cooled magnet

2005

Cryo-cooled magnet

350Ax504m

(2008)

572Ax816m

(2011)

577Ax1040m

(2012)

World Record in 2011 The World’s

First 10m

50Ax10m

(2001)

Higher performance

and

Longer piece length

The World’s

First 100m

RE-based HTS Wire at Fujikura

5

Typical Specifications

＜Schematic of RE-based HTS wire＞

Product Width [mm]

Thickness [mm]

Substrate [μm]

Stabilizer [μm]

Critical Current [A] (@77K, S.F.)

Remarks

FYSC-SCH04 4 0.13 75 20 ≥ 165 Non artificial pinning

FYSC-SCH12 12 0.13 75 20 ≥ 550 Non artificial pinning

FYSC-S12 *1 12 0.08 75 - ≥ 550 Ag protection layer

FESC-SCH04 4 0.11 50 20 ≥ 85 Artificial pinning *3

FESC-SCH12 *2 12 0.11 50 20 TBD Artificial pinning *3

*1 HTS wire without copper stabilizer is available in only 12mm-wide for current lead applications.

*2 Specification of 12mm-wide HTS wire with artificial pinning is to be determined.

*3 HTS wire with artificial pinning is for use in applications at low temperature and high magnetic field.

Stabilizer [Cu plating] 20μm

Protection layer [Ag] 2μm

Superconducting Layer [GdBCO] 2 μm / [EuBCO+BHO] 2.5 μm

Buffer layer [MgO, etc.] 0.7μm

Substrate [Hastelloy®] 75 / 50 μm

Key Technology for High Ic performance I

Ion Beam Assisted Deposition; IBAD

• Fabricating process of buffer layer

• Fujikura original technique (Developed in 1991)

• IBAD enables us to fabricate high-textured

buffer layer at a high production rate.

Assisting

Ion-Source Target

Sputtering

Ion-Source

Substrate

Assisting Ion-Source

Buffer Layer

Substrate

Buffer Layer

Superconducting Layer

1km-length PLD-CeO2/IBAD-MgO Substrate

200 400 600 800 1000

1

2

3

4

5

6

0

Tape length (m)

ΔΦ

of

CeO

2/M

gO (

deg

.)

Avg. 4.17°

STDV 0.1°

6

Key Technology for High Ic performance II

Multi-lanes

IBAD

Substrate

GdBCO

Target

Excimer

Laser

Scanning

Laser

Hot-wall

Heating

Pulsed Laser Deposition; PLD

• Fabricating process of superconducting layer

• Hot-wall heating system is Fujikura original.

• Stable temperature during deposition enables

Superconducting layer with higher performance

than conventional type PLD.

Buffer layer

Superconducting layer

Stabilizer

2μ

m

Cross Sectional TEM Image

0

0.2

0.4

0.6

0.8

1.0

1.2

0 1 2 3 4 5 6 7

Ic @

77

K, S

.F. (

kA)

GdBCO Thickness (μm)

Hot-wall Heating PLD

Conventional PLD c-axis direction

Great crystallinity to the 6 μm thick

7

Ic Uniformity of 4mm-wide - Non AP

Current conduction measurement - 4mm-wide without AP (FYSC-SCH04)

Magnetic measurement @TapestarTM - 4mm-wide without AP (FYSC-SCH04)

0

10

20

30

40

50

0

50

100

150

200

250

0 100 200 300 400 500 600

n-v

alu

e

Ic [

A/4

mm

-wid

e]

Position [m]

Ic

n-value

0 200 400 600

0

100

200

300

Position [m]

Ic [

A/4

mm

-wid

e]

Max

Min

77K, Self-field Ic : max 231A, min 219A, avg 226A, σ=2.37A n-value : min 25

77K, Self-field

8

* Ic criterion：1μV/cm * Range of n-values：10-6~10-7 V/cm

* measured at every 4.7m by four-terminal method

0

10

20

30

40

50

60

70

80

0

100

200

300

400

500

600

700

800

0 50 100 150 200 250 300

n-v

alu

e

Ic [

A]

(12

mm

-wid

e)

Position [m]

Ic

n-value

Ic Uniformity of 12mm-wide - Non AP

Current conduction measurement - 12mm-wide without AP (FYSC-SCH12)

Magnetic measurement @TapestarTM - 12mm-wide without AP (FYSC-SCH12)

0 100 200 300

0

200

400

Position [m]

Ic [

A/4

mm

-wid

e]

Max

Min


77K, Self-field Ic : max 667A, min 645A, avg 656A, σ=5.30A n-value : min 32

77K, Self-field

9

600

800

* Tapestar data above is reference before calibration by actual measurement value.


0

10

20

30

40

50

60

70

0

20

40

60

80

100

120

140

0 50 100 150 200 250 300

n-v

alu

e

Ic [

A]

(4m

m-w

ide)

Position [m]

Ic

n-value

Ic Uniformity of 4mm-wide - AP

Current conduction measurement - 4mm-wide with AP (FESC-SCH04)

Magnetic measurement @TapestarTM - 4mm-wide with AP (FESC-SCH04)

0 100 200 300

0

50

100

150

Position [m]

Ic [

A/4

mm

-wid

e]

Max

Min


Ic : max 107A, min 102A, avg 104A, σ=1.21A n-value : min 19

77K, Self-field

10

77K, Self-field


0

10

20

30

40

50

0

100

200

300

400

500

0 100 200 300

n-v

alu

e

Ic a

t 7

7K

,Se

lf-f

ield

[A

]

Position [m]

Ic

n-value

Ic Uniformity of 12mm-wide - AP (Reference)

Current conduction measurement - 12mm-wide with AP (FESC-SCH12)

Magnetic measurement @TapestarTM - 12mm-wide with AP (FESC-SCH12)

0 100 200 300

0

100

200

300

Position [m]

Ic [

A/4

mm

-wid

e]

Max

Min


11

77K, Self-field

Ic : max 402A, min 384A, avg 394A, σ=4.78A n-value : min 22

400

77K, Self-field

* Tapestar data above is reference before calibration by actual measurement value.


In-field Ic Performance - Non AP (B//c)

12

In-field Ic performance of typical product without artificial pinning (Reference)

Sample : Ic = 573A/10mm-wide@77K, self-field (Superconducting layer thickness: 1.9μm)

* This work includes some data measured at High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University.

0 2 4 6 8 10 12 14 16 18 20

n-v

alu

e

Perpendicular Magnetic Field (B//c) [T]

B//c

20K 30K 40K 50K

65K

77.3K

10K

100

101

102

4.2K

0 2 4 6 8 10 12 14 16 18 20

Ic [

A]

(10

mm

-wid

e)


B//c 101

102

103

20K 30K 40K

50K

65K 77.3K

10K 4.2K

Ic - B - T n-value - B - T

Perpendicular Magnetic Field (B//c)

In-field Ic Performance - Non AP (B//ab)

13

In-field Ic performance of typical product without artificial pinning (Reference)


0 2 4 6 8 10 12 14 16 18 20

Ic [

A]

(10

mm

-wid

e)

Parallel Magnetic Field (B//ab) [T]

B//ab 101

102

103

20K 30K

40K

50K

65K

77.3K

10K 4.2K

104

0 2 4 6 8 10 12 14 16 18 20

n-v

alu

e

Parallel Magnetic Field (B//ab) [T]

B//ab 100

101

20K 30K 40K 50K 65K

77.3K

10K

4.2K 102



Parallel Magnetic Field (B//ab)

In-field Ic Performance - AP (B//c)

14

In-field Ic performance of new product with artificial pinning (Reference)




Perpendicular Magnetic Field (B//c)

0 5 10 15 20 25

n値


20K

30K 40K 50K

65K

77.3K

10K

100

101

102

4.2K

0 5 10 15 20 25

Ic [

A]

(10

mm

-wid

e)


101

102

103

20K

30K 40K

50K

65K 77.3K

10K

4.2K

104

Tensile Stress

15

• Sample : 4mm-wide, 75 μm-thick Hastelloy + 20 μm-thick Cu plating (FYSC-SCH04)

4mm-wide, 50 μm-thick Hastelloy + 20 μm-thick Cu plating (FESC-SCH04)

• Measurement method :

1. Ic measurement without load in LN2 (Ic0)

2. Ic measurement with applying tensile strain in LN2 (Ic1)

3. Ic measurement without load (Ic2) after applying tensile strain in LN2

Ic/Ic0 versus tensile stress Ic/Ic0 versus tensile strain

Tensile stress evaluation at LN2 temperature (Reference)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 200 400 600 800 1000

Ic/I

c 0

Tensile Stress [MPa]

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0.00 0.10 0.20 0.30 0.40 0.50 0.60

Ic/I

c 0

Tensile Strain [%]

◆ Ic1/Ic0 - 75μmt substrate

◇ Ic2/Ic0 - 75μmt substrate







Sample Chuck electrode

Insulation plate

Voltage lead Current lead

Load cell DC power supply

Data logging system

Strain gauge

LN2

Schematic of tensile test

Bending Property

16

Bending property evaluation at LN2 temperature (Reference)



• Measurement method ("Goldacker" continuous bending method) :

1. Ic measurement in straight in LN2 (Ic0)

2. Ic measurement with applying bending strain at LN2 (Ic1)

* Bending direction is tensile direction with superconducting layer outside.

3. Ic measurement in straight (Ic2) after applying bending strain in LN2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

5 10 15

Ic/I

c 0

Bending Radius [mm]

No Ic degradation for

50μmt substrate below

bending radius of 5mm of

the measurement limit





Ic/Ic0 versus bending radius

Current electrode

Voltage electrode

Insulation plate

Sample

Current lead

Schematic of bending test

Compressive Stress in Thickness Direction

17




1. Ic measurement in LN2 (Ic0)

2. Apply compressive load in thickness direction of the sample

at room temperature

3. Ic measurement in LN2 (Ic) after removing compressive load

Compressive stress evaluation in thickness direction at room temperature (Reference)

Ic/Ic0 versus compressive stress

No Ic degradation below

400 MPa of compressive

stress in thickness direction

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 200 400 600 800

Ic/I

c 0

Compressive Stress [MPa]

◆ Ic/Ic0 - 50μmt substrate

◆ Ic/Ic0 - 75μmt substrate

Al buffer plate

Stainless steel bar

Sample 50mm

Compressive load φ50mm

Schematic of compressive test

in thickness direction

Compressive Stress in Width Direction

18

• Sample : 4mm-wide, 50 μm-thick Hastelloy + 20 μm-thick Cu plating (FESC-SCH04)


1. Ic measurement in LN2 (Ic0)

2. Apply compressive load in width direction of the coiled sample

at room temperature

3. Ic measurement in LN2 (Ic) after removing compressive load

Compressive stress evaluation in width direction at room temperature (Reference)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 100 200 300 400

Ic/I

c 0

Compressive Stress [MPa]

Ic/Ic0 versus compressive stress

No Ic degradation for

50μmt substrate below

100 MPa of compressive

stress in width direction

Coiled wire sample

Inner diameter: 30mm

Wire length: 1.35m

Schematic of compressive test

in width direction

Applications of Superconductor

19

Power Cable

Transformer

FCL

MRI

NMR

Higher operating temperature (no use of liquid helium)

Higher critical current at higher magnetic field

Size reduction and lighter weight

Advantages of

RE-based HTS

LN2

LHe

Next Generation Nuclear fusion

Reactor

Medical Accelerator

SMES

Wind Power

Power Cable

transformer

Marine Motor

Industrial Motor

Fault Current Limiter

Magnetic Field

Operating Temperature

Bi-based HTS Applicable Area

RE-based HTS Applicable Area

MRI

Nuclear Fusion Reactor （ITER）

Si Single Crystal

NMR LTS Applicable Area

Marine Motor

20

20 cm

110 cm

80 cm

GM cryocooler

The magnet excitation performance up to

5 T retained for 4 years after the fabrication

M. Daibo, et al.,IEEE Trans. Appl. Supercond. 23-3 (2013) 4602004

Fujikura's 10 mmw Y-based HTS wire

Total tape length : 7.2 km (300 m x 24)

Stored energy : 426 kJ

Composed of 24 pancake coils

Total number of turns : 5775

Operating temperature : 25 K

Development of 5 T 2G HTS magnet

5 T 2G HTS cryocooled magnet

developed successfully in 2012

Measured AC loss

77 K

67 K

66kV/5kA Class Power Cable (NEDO Program)

21

< Design and Fabrication >

Development of HTS Power Cable with 500A class Y-based Wire

HTS cable

Terminal

Vessel

Cooling system

This work includes results supported by NEDO

Verification of AC Loss reduction with higher critical current HTS wires

Single-core in one pipe cable system /66kV-5kA /10m class long

Long term current loading test : 20 cycles (1 cycle = 8h ON / 16h OFF)

Target AC loss : < 2 W/m @5kA

Measured AC loss : 1.4W/m@77K, 1.0W/m@67K

Fujikura has succeeded in developing Y-based HTS power cable with 5 kA and extremely low AC loss 1.4 W/m in 2013.

Items Specifications

Former Stranded copper wires (140 mm2), 20 mmφ

HTS conductor (Ic=14 kA)

4mm-wide wires, 4 layers Ic = 240 A/4 mm-w

Electric insulation

Craft papers (6mm-thick)

HTS shield (Ic=12.7 kA)

All 4mm-w tapes, 2 layers Ic = 240 A/4mm-w

Copper shield Copper tapes (100mm2), 44mm

Core protection non-woven fabric, 45mmφ

Cryostat / Outer sheath

Stainless steel double corrugated pipes with PE jacket, 114mmφ

http://www.nedo.go.jp/news/press/AA5_100196.html

Basic Instruction of Soldering

22

Solder Sn-Pb Sn-Bi Sn-Ag-Cu Sn-In Sn In

Composition [wt%]

Sn63-Pb37 Sn42-Bi58 Sn96.5-Ag3

-Cu0.5 Sn48-In52 Sn (4N) In (4N)

Melting point [deg C]

183.0 138 217 118 231.9 156.6

Resistivity [nΩm]

297K 167.3 510.6 154.0 168.1 123.1 90.3

77K 34.6 178.8 19.4 90.3 23.0 17.5

• It shall be generally recommendable to use solders with low melting point and to heat below 200

degrees C within few minutes. In case it would be difficult to melt solder, heating over 220 deg C

could be also acceptable with full attentions.

• Sn-Pb based solder would be generally used but other solders could be also available depending on

application designs or environmental regulation.

• Sn-Bi based or more preferably Sn-Bi-Ag based solder would be recommendable for HTS wires with

silver protection layer such as FYSC-S series. Especially solder including Ag is relatively easy to solder

silver protection layer.

* Resistivity is measured value at Fujikura.

Physical properties

Recommendable solders and heating temperatures

0.85

0.90

0.95

1.00

1.05

0 2 4 6 8 10

Ic/I

c0

Elapsed time [min]

200 deg C

230 deg C

250 deg C

270 deg C

290 deg C

0.85

0.90

0.95

1.00

1.05

0 2 4 6 8 10

Ic/I

c0

Elapsed time [min]

230 deg C

250 deg C

270 deg C

290 deg C

Basic Instruction

23

Ic degradation during heating

* It shall be generally recommendable to heat below 200 degrees C within few minutes. Heating 230 degrees C

within 10 minutes or higher heating temperature could be also acceptable with full attentions.

* These conditions shall not be necessarily applicable to HTS wires with Ag protection layer due to soldering

erosion of Ag layer.

Non artificial pinning (FYSC series) Artificial pinning type (FESC series)

Notes for Handling

24

• Do not fold.

• Max. bending radius : 15mm.

• Max. tensile strength : 400 MPa.

• Prevent contact with water/moisture.

• Do not twist strongly.

• Clamp both sides while cutting.

• Polyimide tape may become loose when cut or contacted by a sharp object.

Handling

• Keep at room temperature, away from heat and/or moisture.

• Avoid dew condensation environment and/or corrosive atmosphere.

• No heavy objects on a superconducting wire or a reel.

• Do not deform a reel.

Storage

Japan, Asia and other areas

Fujikura Ltd. 1440, Mutsuzaki, Sakura-shi, Chiba 285-8550, Japan

Phone: +81-43-484-3048

E-mail: [email protected]

http://www.fujikura.co.jp

Europe

Fujikura Europe Ltd. C51 Barwell Business Park, Leatherhead Road

Chessington, Surrey, KT9 2NY, UK

Phone: +44-20-8240-2000


http://www.fujikura.co.uk

America

Fujikura America, Inc. 8024 Glenwood Ave, Suite 115

Raleigh, NC 27612, US

Phone: +1-919-847-6173


Contact Information

25

Documents

Introduction of FUJIKURA RE-based HTS Wire...Sample : Ic = 387A/10mm-wide@77K, self-field (Superconducting layer thickness: 2.2μm) * This work includes some data measured at High