Collaboration Mtg, St Charles, IL 10/5-6, 2005 A. Ghosh1 Conductor R&D Plan Arup K. Ghosh BNL.

Collaboration Mtg, St Charles, IL 10/5-6, 2005

A. Ghosh 1

Conductor R&D Plan

Arup K. Ghosh

BNL


A. Ghosh 2

Introduction

• The first TQ magnets, TQC01 and TQS01 and SQ-02 use– 0.7mm Modified Jelly-Roll strands “borrowed” from FNAL’s

inventory• 27-strand cable with 1.0 Deg keystone angle• Strand is of the 54/61 design with large effective filament

diameter ~ 70-80 m• Using “Nominal” heat treatment Jc > 2000 A/mm2 but

the strand has a low stability current Is• We now understand that Is in unstable strands is strongly

influenced by “dynamic” effects – Improve thermal environment Increase RRR of

stabilizing copper– Achieve this by preventing excessive reaction of Nb-

barrier – Optimize Reaction Time/Temp to increase the stability

current to be well above magnet operating current


A. Ghosh 3

Heat-Treat Optimization

Jc(12T-15T)

RRRBc2

HT-Temp 635C-695C

& TimeHigher Bc2 at

higher T

Strand Stability for large Deff


A. Ghosh 4

Ic and Is of virgin and of Strands Extracted from LARP Proto-type Cables

Wire ID FIELD, T *12 11HT parameters Temp TIME Ic(A) Ic(A) Is(A) RRR

ORE-205-virgin 210/48+400/48+665/72 665 72 439 533 522 12913R-A-Extr. 210/48+400/48+665/72 665 72 435 523 419 13910R-A-Extr. 210/48+400/48+665/72 665 72 443 532 412 13ORE-206-C-Virgin 210/48+400/48+665/72 665 72 442 531 506 12

ORE-206-C-Virgin 210/48+400/48+650/72 650 72 417 513 887 98913R-A-Extr. 210/48+400/48+650/72 650 72 404 496 637 73910R-A-Extr. 210/48+400/48+650/72 650 72 436 531 837 84

913R-A-Extr. 210/48+400/48+635/72 635 72 389 480 887 202ORE-205-virgin 210/48+400/48+635/72 635 72 389 478 1200 302

ORE-205-virgin 210/48+400/48+650/48 650 48 418 511 1200 247913R-A-Extr. 210/48+400/48+650/48 650 48 389 477 1100 189910R-A-Extr. 210/48+400/48+650/48 650 48 397 487 1200 218

ORE-205-virgin 210/48+400/48+635/48 635 48 373 461 1200 310913R-B-Extr. 210/48+400/48+635/48 635 48 369 457 1200 275

* 12T is an extrapolation using the Summers' formulation


A. Ghosh 5

Commercial sources of high Jc Nb3Sn

• With the exception of ShapeMetal Innovation, Netherlands, (SMI), which uses Powder-in-tube technology (PIT) and has delivered strand to FNAL in the past, there is only one reliable source of high-Jc strand in the US.

• Oxford Superconducting Technology (OST)– MJR Conductor has been phased out– Present technique is RRP (Rod-Restack Process)

• Uses a distributed barrier approach• Jc (12T) ~ 3000 A/mm2

• Effective Filament Diameter Deff~ Sub-element Diameter

– Deff scales inversely with increasing number of Sub-elements


A. Ghosh 6

RRP strand

• Long-lead item ~ 6-9 months after placing order• SC vendor planning ~12-13 months• Under the direction of the Conductor Development

Program, OST has developed strands with increasing number of sub-elements to reduce Deff

Billet 7054 54/61

Billet 7904 126/127

Billet 8079 90/91


A. Ghosh 7

RRP Strand for LARP

– OST has the most experience in fabricating strands of 54/61-stack design. This is considered a “production” wire used in the NMR business

– Very limited experience with the 91 or the 127 stack design. These billets are presently considered by OST to be R&D billets.

• For FY06 LARP would like to use strands with the 84/91-stack design

• Why? Why not use the “production” 54/61 strand ?– Stability will improve with decreasing sub-element

diameter• Question is how to move from R&D to “production” at OST


A. Ghosh 8

Nb3Sn Strand Specification84/91 Design

Process Ternary RRP Nb3SnDiameter, mm 0.7 ± .0025

Jc(12 T), A/mm2

≥ 2400

Deff, µm < 60

IS, A > 1200 A

Cu-fraction, % 50 ± 2RRR ≥ 100RH twist, mm 15 ± 1Minimum Piece length, m 350High temperature HT duration, h ≥ 48


A. Ghosh 9

Nb3Sn Strand Specification54/61 Design

Process Ternary RRP Nb3SnDiameter, mm 0.7 ± .0025

Jc(12 T), A/mm2

≥ 2400

Deff, µm < 70

IS, A > 1200 A

Cu-fraction, % 50 ± 2RRR ≥ 100RH twist, mm 15 ± 1Minimum Piece length, m 350High temperature HT duration, h ≥ 48


A. Ghosh 10

Conductor Development Program

• CDP has been the main driver in OST’s high-Jc strand R&D. – It continues to fund this development in FY06

– Main Goals reduce Deff, billet “scale-up”, (NbTi)3Sn

• LARP can take advantage of the strand that is in the CDP inventory to conduct strand characterization for use in TQ-type cable

• LARP can also “borrow” from the CDP inventory

• At present OST is fabricating strand for CDP that is similar to strand being considered for LARP purchase


A. Ghosh 11

CDP-R&D Inventory

Compiled with D.R Dietderich

Yield of billet 8502 is ~ 50% due to wire breakage

Billet 8521 is in process, yield not known

Billet Type StackRod

Composition

Diameter

(mm)

non-Cu (%)

Weight (kg)

Length (m)

CDP PurChase

Delivery Date

8079 RRP 90/91 Nb-(Ti) 0.7 59 30 6203 R&D at LBNL

8220 RRP 54/61 Nb-Ta 0.7 53.8 36 10776 Y at LBNL

xxxx RRP 54/61 Nb-Ta 0.7 50 35 Y 11/30/2005xxxx RRP 84/91 Nb-Ta 0.7 50 35 Y 11/30/2005xxxx RRP 84/91 Nb-Ta 0.7 50 90 Y 3/31/20068502 RRP 84/91 Nb-Ta 0.7 50 15 R&D 9/30/20058521 RRP 108/127 Nb-Ta 0.7 50 30 R&D 9/30/20058466 RRP 198/217 Nb-Ta 0.7 50 NM R&D 9/30/2005


A. Ghosh 12

Comments• 30 kg can be fabricated into 5 UL’s each 65m long. Each UL is for a TQ-

coil

• With the exception of billet 8079, all the strand in CDP inventory is the high Sn-content capable of a Jc of 3000 A/mm2. The most recent billet 8220 (54/61-design) has this Jc and a RRR ~ 200. With this RRR the stability current is ~ 1000-1100 A.

• Most of the RRP strand at 0.7mm have yet to be cabled as a TQ-cable with 1.0 deg keystone. LBL has recently made a short (17m) trial piece of 27-strand TQ cable using strand from 8220. This is being evaluated for Ic, Is and RRR.

• A short length ~ 4m of cable has also been fabricated using strand from 8079 (90/91-design), this too is under evaluation. Strands from this billet show stability currents > 1200A.

• For strands with either the 61, 91 or 127 stack, the key parameter that ensures a high stability current is the RRR of the copper stabilizer.

– Provided the copper remains clean, strand stability increases as the stack number is increased i.e. sub-element size is decreased


A. Ghosh 13

Recent OST Billets

WireID HT_Temp HT_Time Jc(12T) Ic(12T) Ic(11T) Is RRR54/61-DesignRRP-8220-4 665 50 3022 622 750 1125 171RRP-8220-4 665 50 3208 660 796 1012 190RRP-8220-4 665 50 3080 634 761 1125 178RRP-8220-4 680 48 3169 652 773 111RRP-8220-4 650 48 2923 602 731 1075RRP-8220-4 650 96 3108 640 773 112590/91-DesignRRP-8079-7 635 48 2473 561 676 >1200 357RRP-8079-7 635 36 2325 528 638 >1200 344RRP-8079-7 635 48 2457 558 670 >1200 356126/127-DesignRRP-7904 650 72 2257 513 633 300 4RRP-7904 635 72 2041 463 578 525 8.8


A. Ghosh 14

Target Program

Sept 26, 2005 Type Strand Length Gradient Peak Bore FY05 FY06 FY07 FY08 FY09

process [m] [T/m] Field [T] [mm]

MODEL MAGNETS

Technology Quad (TQ) cos(2q) MJR 1 > 200 90 2*

RRP 1* 2

Long Quad (LQ) cos(2q) RRP 4 > 200 90 1 1

High Gradient Quad (HQ) cos(2q) RRP? 1 > 250 90 1 1

SUPPORTING R&D

Practice Coil (PC) cos(2q) RRP 4 N/A 90 2

Sub-scale Quad (SQ) block MJR 0.3 ~100 110 1*

RRP 1* 1* 1

Short Racetrack (SR) block RRP 0.3 10-12 N/A 1 1* 1

Long Racetrack (LR) block RRP 4 10-12 N/A 1 1

* In addition to building new coils there will be several revised configuration tests using existing coilsRRP: Rod Restack Process (84/91)MJR: Modified Jelly Roll


A. Ghosh 15

Total Conductor Estimate

Series# of Magnets Kg/Magnet Total

TQ 5 35 175

LQ 2 165 330

HQ 2 88 176

Series# of Magnets Kg/Magnet Total

PC 2 40 80

SQ 4 10 40

SR 3 5 15

LR 2 60 120

Total

Total 936 kg

Plan for 1100 kg


A. Ghosh 16

Procurement Plan

1100 kg

FY06300 kg

FY07400 kg

FY08400 kg

85 kgFNAL

95 kg3/31/06

60 kg7/31/06

60 kg10/31/06

Plan A54/61

Plan B84/91

Low-Risk

Low Risk

Higher Risk


A. Ghosh 17

Procurement Strategy

• CDP has two billets on order which uses the same sub-element with the potential for Jc(12T) ~ 3000 A/mm2

– One uses 54/61 design– The other 84/91 design – Delivery 11/31/05

• CDP is also placing an order for 90 kg for high Jc wire using the 84/91 design Delivery 3/31/06

• LARP will place an initial order for 95 kg (this is the yield from one sub-element extrusion billet)– 54/61 design Delivery 3/31/06

This allows for material to be in the pipeline that we are certain to have in hand for the magnets being fabricated in FY06. If the 84/91 billets for CDP are successful then LARP could “swap” that with the 54/61 wire delivered under its order


A. Ghosh 18

Summary

• Present Status– Draft specification sent to OST– Wire from Billet 8502 (84/91) arriving LBL 10/10/30– This wire needs to be characterized for Ic, Is and RRR– Cable using billet 8220 (54/61) under investigation

• LARP order needs to be placed soon

Collaboration Mtg, St Charles, IL 10/5-6, 2005 A. Ghosh1 Conductor R&D Plan Arup K. Ghosh BNL.

Documents

Transcript of Collaboration Mtg, St Charles, IL 10/5-6, 2005 A. Ghosh1 Conductor R&D Plan Arup K. Ghosh BNL.