larp strand: specifications, procurement and measurement plans

Conductor Review Oct 16-17, 2013

LARP Strand :Specs. Procurement, Measurement- A. Ghosh

1

LARP Strand: Specifications, Procurement and

Measurement Plans

BNL -FNAL - LBNL - SLAC

HiLumi-LHC/LARP Conductor and Cable Internal Review

Oct 16-17, 2013By Video

Arup K. Ghosh (BNL)



2

Outline

1. Introduction2. QXF Magnet Strand

a. Specification3. QXF Strand Procurement Plan

a. Implementation of 169 designb. Details of Plan

4. Strand Evaluation5. Summary



3

Introduction For the QXF Magnets we use RRP® wire from

Oxford Superconducting Technology Strand diameter 0.85 mm

Whereas so far HQ has used Ta-Ternary strand, QXF will use Ti-Ternary Nb3Sn

(Nb- 1.5 at% Ti)3 -Sn Cable is a 40- strand Rutherford Cable with

stainless steel core Wire is currently based on the 108/127 design Specification for the strand is a “performance -

based specification” that satisfies the minimum requirements as set by the magnet design.



4

Ta-Ternary vs. Ti-Ternary 0.7 mm strand from CDP

350

400

450

500

550

600

650

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Sample loadedSample unloaded

Crit

ical

Cur

rent

, Ic (A

)

Applied Strain, (%)

Ec = 0.1 V/cm

T = 4 KB = 12 T

irr

~ 0.62 %

max

~ 0.37 %

A'B'C' G'H' I'J'

CDE F GH IJ

A B

D'E'F'

KL

MN

OP

Q

R

S

K'L'M'N'O'

P'

Q'

R'

S'

(b)

Ti-doped RRP Nb3Sn wire

irr,0

= 0.25 %

250

300

350

400

450

500

550

600

0 0.1 0.2 0.3 0.4 0.5 0.6


Crit

ical

Cur

rent

, Ic (A

)

Applied Strain, (%)

Ec = 0.1 V/cm

T = 4 KB = 12 T

irr

~ 0.37 %max

~ 0.33 %

A' B'C'

G'

H'

I'

J'

CDE

F

G

H

I

J

A B

D'E'F'

(a)

Ta-doped RRP Nb3Sn wire

irr,0

= 0.04 %

350

400

450

500

550

600

650

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7


Crit

ical

Cur

rent

, Ic (A

)

Applied Strain, (%)

Ec = 0.1 V/cm

T = 4 KB = 12 T

irr

~ 0.62 %

max

~ 0.37 %

A'B'C' G'H' I'J'

CDE F GH IJ

A B

D'E'F'

KL

MN

OP

Q

R

S

K'L'M'N'O'

P'

Q'

R'

S'

(b)

Ti-doped RRP Nb3Sn wire

irr,0

= 0.25 %

250

300

350

400

450

500

550

600

0 0.1 0.2 0.3 0.4 0.5 0.6


Crit

ical

Cur

rent

, Ic (A

)

Applied Strain, (%)

Ec = 0.1 V/cm

T = 4 KB = 12 T

irr

~ 0.37 %max

~ 0.33 %

A' B'C'

G'

H'

I'

J'

CDE

F

G

H

I

J

A B

D'E'F'

(a)

Ta-doped RRP Nb3Sn wire

irr,0

= 0.04 %

Influence of Ta and Ti doping on the irreversible strain limit of ternary Nb3Sn superconducting wires made with restacked-rod process*N. Cheggour, L. F. Goodrich, T. C. Stauffer , J. D. Splett , and X.F. Lu, A. K. Ghosh, G. AmbrosioSupercond. Sci. and Tech., 20, (2010)

Ti-doped Nb3Sn wire more strain tolerant than Ta-dopedirr increases to 0.25 % from 0.04 %

This has been confirmed for 0.8 mm (Nb-1.5 at% Ti)3-Sn strand irr = 0.32-0.35 % as well as strands with 108 and192 filaments. Expect 169 design to be similar.



5

Present SpecificationLARP-MAG-M-8004 Rev. A

Strand Diameter, mm 0.85Jc(12 T) at 4.2 K, A/mm2 > 2650

Ic, A > 684Jc(15 T) at 4.2 K, A/mm2 > 1400

Ic, A > 381ds, µm (nominal)

< 60Cu-fraction, %

> 53 Cu/non-Cu

> 1.13RRR

> 150Piece length

> 750 m

ds sub-element diameterJc Critical Current DensityRRR residual resistivity ratio

108/127

Reduced-Sn content to

obtain high RRR



6

Implementing 169 design wire Motivation for adopting 132/169 (144/169) design

wire smaller filament diameter: increase stability, lower

magnetization

Strand Design 54/61 84/91 108/127 132/169 192/217

# of Sub-elementsD w , mm 54 84 108 132 192

0.9 83 66 58 53 440.85 78 63 55 50 41

0.778 71 57 50 46 380.7 64 52 45 41 34

HQ02 strand at 0.778 mm is 108/127

For QXF with 0.85 mm strand a similar filament diameter requires 132 filaments. Note: 108 to 132 is only 10% change in filament diameter

Cu/Non-Cu= 1.2



7

• For LARP QXF magnet• SQXF01 Magnet will use 108/127 strand• Presenting a plan to use 169-strand in SQXF02 and in

LQXF magnets• In FY14 with CDP funds, contracts were placed at OST for

• 180 kg of 144 or132 filament strand with “Reduced-Sn”• 90 kg of wire 169-design with 30% increased barrier

thickness and “normal-Sn” content. •LARP has an existing PO of 275 Kg for 108/127 meeting the specification shown previously

• Convert to 169- strand with “reduced-Sn”.•All future LARP contracts in FY15 for 169-strand

Implementing 169 design wire



8

Procurement Plan for QXF magnets Require 12 + (1 PC) coils for SQXF; unit length 170 m Require 17 + (1 PC) coils for LQXF; unit length 450 m Assuming 10% loss in strand from cable mapping Total length of strand for SQXF: ~ 470 Kg (94 km) Total length required for LQXF: ~ 1760 Kg (352 km) Present Inventory

350 Kg (Ti-Ternary 108/127 design) 200 Kg (Ta-ternary 108/127 design) Used for Practice coils

CDP (Conductor Development Program) will provide ~ 520 Kg 270 Kg 132/169 design May – July’14 250 Kg June’15

LARP procurement in FY’13 for 275 Kg (Ti-ternary 108/127) Convert to 169-strand ?

Additional orders to be placed in FY15: ~ 900 Kg, either as one lot or two lots of 550 and 350 Kg



9

Strand Procurement and Cabling Schedule

• For LARP QXF magnet• Procurement and Cabling schedule set by the

demands of coil fabrication• Cabling start is set 4 months before start of coil winding

• Typical time for cabling is 2 weeks • Braided Insulation at New England Wire

• 4 weeks• Strand procurement time is presently at 13 months

• Partial delivery can start as early as 9 months



10

Month

LARP Strand

Delivery kg

Cabling Run and End Use /

[Coil ID]Coil Winding

Start Date

Strand Req. kg

Cable Unit

Lengths

Ta 108/127 0.85mm

kg

Ti-108/127

0.85 mm kg

Ti-108/127 0.85 mm CDP kg

Ti-144/169 0.85

mm kg

Ti-144/169 0.85 mm CDP kg

Oct-13 SQXF- PC01 39 1 124 350Nov-13 SQXF- PC02 Practice winding test 39 1 124 310Dec-13 SQXF-03 39 1 124 271

Jan-14 SQXF-04,05 79 2 124 192Feb-14 SQXF-06, 07 SQXF- PC01 79 2 124 114Mar-14 90 SQXF-08 SQXF- PC02 39 1 124 75 90Apr-14 SQXF-C09 SQXF- C03 39 1 124 165 90 51May-14 165 165 396 180Jun-14 SQXF- C04 165 396Jul-14 SQXF- C05 165 486 90

Aug-14 LQXF-PC01 SQXF- C06 104 1 61 486Sep-14 LQXF-C01 SQXF- C07 104 1 61 382

Oct-14 SQXF- C08 61 382Nov-14 SQXF-C10 39 1 61 343Dec-14 SQXF-C11 LQXF-PC01 39 1 61 303Jan-15 SQXF-C12 LQXF-C01 39 1 61 264Feb-15 SQXF-C13 SQXF-09 39 1 61 225Mar-15 SQXF-10 61 225Apr-15 LQXF-C02 104 1 61 121May-15 LQXF-C03 SQXF-11 104 1 61 267 250

Strand Procurement and Cabling Plan



11

Apr-15 LQXF-C02 104 1 61 121May-15 LQXF-C03 SQXF-11 104 1 61 267 250Jun-15 LQXF-C04 SQXF-12 104 1 61 163Jul-15 200 LQXF-C05 SQXF-13 104 1 61 259

Aug-15 LQXF-C06 LQXF-C02 104 1 61 155Sep-15 200 LQXF-C03 61 355Oct-15 150 LQXF-C04 61 505Nov-15 LQXF-C05 505Dec-15 LQXF-C07 LQXF-C06 104 1 401Jan-16 LQXF-C08 104 1 297Feb-16 LQXF-C09&C11 208 2 89Mar-16 200 LQXF-C10&C12 104 2 185Apr-16 LQXF-C07 185May-16 150 LQXF-C08 335Jun-16 LQXF-C13&C15 LQXF-C09&C11 104 2 231Jul-16 LQXF-C14&C16 LQXF-C10&C12 104 2 127

Aug-16 LQXF-C17 104 1 23Sep-16 LQXF-C13&C15 23Oct-16 LQXF-C14&C16Nov-16 LQXF-C17



12

Cost and Yield• In going from 54/61 to 108/127, the yield dropped by ~

14% and the average piece-length decreased. Cost premium ~ 14%.

• Based on recent quote from OST, 144/169 wire cost is ~ 14% higher for the same performance specification. OST expects yield to be less than 108/127. Note that for the 132-filament strand the cost would be slightly lower (less Nb) and fractionally higher expected yield. 144 filament strand will have higher Ic and lower Cu %.

• CERN procurement results can yield some insight in comparing 108/127 with 132/169.

• There is loss of Jc as one goes from 54 to 108 to 132 filaments and a higher probability of lower RRR as the number of filaments increases for the same wire diameter.

• “Reduced-Sn” will mitigate this.



13

LARP Near Term Measurement Plan• To fast-track the evaluation of the 169-strand, OST has

offered one billet of 132/169 with “normal-Sn” delivered in early Jan’14 under the CDP contract.

• Plan to use this delivery to make lengths of QXF cable for evaluation and comparison with 108/127 strand cable

• Mechanical tests, metallographic test, electrical test using extracted strands

• windability, sub-element damage, cabling degradation

• HT optimization using 640 °C/48h, 650 °C/48h and 640 °C/96h.

• In Mar-Apr’14 we will use wire delivered under LARP contract which uses “reduced-Sn” to do a similar evaluation.



14

Summary

• Strand specification based on minimum Ic, Cu fraction, RRR and piece-length and a specific strand design

• Plan shown implements 169-strand in SQXF02 magnet and all LQXF.

• Strand procurement has been planned to meet coil winding schedule.

• Cabling start precedes coil winding by ~ 4 months• Specification and production QA plan to be formalized prior to

placing contract in FY’15



15

End of Presentation



16

Risk Mitigation for strand

• For LARP QXF magnet• Strand quantities outlined is just sufficient for the 17 coils of

LQXF• Loss of UL during cabling assumed to be zero. Typically this

happens if there is a strand cross-over in the cable. This is low risk as cabling at LBNL has not experienced such an event.

• Plan to have an option in the 350 Kg lot order for extra 200 Kg of wire sufficient for 2 Unit Lengths of LQXF ?



17Nov 8-10, 2010 CM15 @SLAC

Arup Ghosh17

Conductor Qualification -1• Billet Qualification

– Rely on OST data– Meets minimum performance specification– OST data will be cross-checked with measurements of at least

one sample per billet• Cable Qualification

– This is important and needs to be completed prior to coil winding.

– Mechanical tests, metallographic test, insulation thickness – Electrical test: minimum 3 extracted strand and one round wire

– Heat Treatment schedule (HT) as specified for coil reaction• Coil HT Qualification

– Witness sample tests of extracted strands– Tests done at one measurement laboratory– Minimum of four extracted strand and one round wire

larp strand: specifications, procurement and measurement plans

Documents

larp strand

taternary strand

or132 filament strand

strand rutherford cable

ti3sn strand eirr

ghosh bnlconductor review

design wireconductor

larp qxf magnetsqxf01