Prospects for High Temperature Superconducting Magnets

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Prospects for High Temperature Superconducting
Magnets

• David Larbalestier
• National High Magnetic Field Laboratory, Florida
  State University, Tallahassee FL 32310

NHMFL User Committee Meeting October 2, 2009
YBCO properties Aixia Xu, Fumitake Kametani, Jan
Jaroszynski, Youri Viouchkov YBCO coil RD and
test Ulf Trociewitz, Huub Weijers, Patrick
Noyes, Bill Shepherd, Ken Pickard, Denis
Markiewicz Bi-2212 Coil and test Ulf
Trociewitz, David Myers, Jianyi Jiang, Eric
Hellstrom, Huub Weijers, Patrick Noyes YBCO
conductor by SuperPower (Venkat Selvamanickam,
Yi-Yuan Xie, Drew Hazelton and colleagues) Bi-2212
conductor by Oxford Superconducting Technology
(Yibing Huang, Hanping Miao and colleagues) and
processing by Jianyi Jiang, Tengming Shen,
Michael LoSchiavo, Eric Hellstrom)
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Themes (November 2008)

• All superconducting high field magnets provide a
  technology pull for HTS conductors
• The needed conductors are now here and have been
  tested in small coils made at the MagLab to B gt
  30T
• An all superconducting user magnet has been
  designed (32 T, 34 mm 4K bore)
• The January NSF Major research instrumentation
  program provides a vehicle to seek funding for
  such a magnet

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Some words from the 2008 User Committee report

• The prospect of an all-superconducting 32 tesla
  magnet is very exciting. This could reduce
  operating costs while allowing more measurements
  to be done, particularly for fixed field
  measurements such as NMR and specific heat, and
  indeed this is an exciting development for the
  field as a whole.

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January 2009 Major Research Instrumentation (MRI)
Program Submission

• MRI Development of a 32 T All-Superconducting
  Magnet System using YBa2Cu3O7-x Coated Conductors
•  
• PIs Denis Markiewicz and David Larbalestier,
  (National High Magnetic Field Laboratory, Florida
  State University), and Stephen Julian (Department
  of Physics, University of Toronto).
•  
• The Intellectual Merit of Our Goals Our goal is
  an all-superconducting 32 T magnet. The enabling
  technology is YBCO (YBa2Cu3O7-x) thin-film coated
  high temperature superconductor (HTS-CC) which
  has just become available in 0.1-1 km lengths.
  YBCO CC offer the possibility of transforming
  superconducting magnet technology, because its 4
  K critical fields are well above 100 T, compared
  to the 30 T of Nb3Sn from which magnets can only
  made with maximum fields of about 22 T.

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32 T Magnet Parameters
Total field 32 T Field inner YBCO coils 17
T Field outer LTS coils 15 T Cold inner bore 32
mm Uniformity 5x10-4 1cm
DSV Current 186 A Inductance 436 H Stored
Energy 7.54 MJ
YBCO
Nb3Sn
NbTi
Good news fully funded at 2 million over 3
years starting 10/09 talk by Denis Markiewicz
on the tour
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The Global Context is provided by COHMAG-
Opportunities in High Magnetic Field Science
2004

• Grand magnet challenges
• 30T NMR (All SC)
• 60T Hybrid (R SC )
• 100T Long Pulse (R)

All require materials in conductor forms that
were not available in 2004 They now are!

• Means
• .the involved communities users and magnet
  builders should cooperate to establish a
  consortium whose objective would be to address
  the fundamental materials science and engineering
  problems that will have to be solved.. COHMAG
  report 2004

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..and locally by user demands, the power bill,
and the NSF budget.

• Provides the worlds highest magnetic fields
• 45T DC in hybrid, 32 mm warm bore
• Purely resistive magnets 35T in 32 mm warm bore,
  31 T in 50 mm bore and 19T in 195 mm warm bore
• 20 MW resistive magnet 2400/hr at full power

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HTS greatly extends the capability at 4K
Courtesy Peter Lee www.asc.magnet.fsu.edu
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YBCO Coated conductor by SuperPower (Guilderland
NY) available since mid 2007

• Phenomenal Jc in the YBCO - 20 x 106 A/cm2 at
  25T
• YBCO is 1 of cross-section
• 50 is high strength superalloy

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YBCO Test Coils 09 update
SuperPower I. Bmax 26.8 T ?B 7.8 T
SuperPower II. Bmax 27 T ?B 7 T
NHMFL I. Bmax 33.8 T ?B 2.8 T
NHMFL II. Bmax 20.4 T ?B 0.4 T
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Bi-2212 round wire technology too layer
winding, cablable conductor
Bi2212 Ag-sheathed conductor before heat treatment
Bi-2212 filaments after heat treatment

• Round wires enable cabling into the high current
  conductors needed for large magnets or fast ramp
  magnets

Arno Godeke Magnet Group, LBNL
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HTS insert coil trends 09 update
year BABHTSBtotal T Jave A/mm2 Stress MPa JavexBAxRmax Stress MPa JexBAxRmax
2003 2008 2008 BSCCO 20525 T(tape) 20222 T(wire) 31131 T (wire) 89 92 80 125 69 47 175 109 89
2007 YBCO- SP 197.826.8 T 259 215 382
2008 YBCO-NHMFL 312.833.8 T 460 245 324
2009 YBCO -SP 207.227.2 211 185 314
2009 YBCO-NHMFL (strain limited) 200.1 20.1 241 392 611
f 163 mm
f 39 mm
Bi-2212 f 38 mm
YBCO SP 2007 f 87 mm
Summary by Weijers
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An HEP Collaboration to develop round wire 2212
conductor and coil technology (Arup Ghosh (BNL) ,
David Larbalestier (FSU), and Alvin Tollestrup
(FNAL)) - funded August 09 at 4 million over 2
years

• Conductor understanding (PIs Eric Hellstrom
  (NHMFL) and Terry Holesinger (LANL)
• Conductor mechanical properties Najib Cheggour
  (NIST) and Arno Godeke (LBNL)
• Cable development Emanuela Barzi (FNAL) and Al
  McInturff (TAMU/LBNL)
• Quench analysis Soren Prestomon (LBNL) and
  Justin Schwartz (NCSU)
• Coil Development Ulf Trociewitz (NHMFL) and
  Arno Godeke (LBNL)
• Industrial conductor development Ken Marken
  (LANL) and Arup Ghosh (BNL)

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Rutherford and Roebel cables needed for large
magnets

• Rutherford cable (flattened, fully transposed
  cable) works well for round wire 2212
• Major task of the HEP collaboration
• YBCO tape cannot be Rutherford cabled but cabling
  by the Roebel method is possible
• Under evaluation by Karlsruhe and General Cable
  and IRL (NZ)

Predicted perp. field Ic of 15 strand, 5 mm wide
Roebel YBCO cable parallel 5-7 times higher
YBCO Nick Long (IRL) and Andrew Priest (General
Cable NZ)
Bi-2212
Arno Godeke, Magnet Group, LBNL
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Developing the case for a long term RD effort

• Magnet-pull focus
• NMR HTS coil
• 40 T small HTS coil (31 T background)
• Finding the limits (stress, energy density,
  quench.)
• High current cables (e.g. Zeemans)
• Conductor-pull focus
• YBCO coated conductors are evolving rapidly
  driven by 40-77K, 0-3 T use what about 4 K,
  20-40 T properties?
• Bi-2212 is round wire and multifilament but has
  intrinsically poor vortex pinning due to large
  electronic anisotropy

• 2212 and YBCO have 3 times the critical fields of
  Nb3Sn but their conductor technology is still
  primitive.
• What we really want are the vortex pinning
  properties of YBCO and the grain boundary
  properties of 2212
• Why not..?

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Timelines and Progress

• 2006 Renewal proposal takes up the COHMAG
  challenge
• 2007 experimental concentration on 2212 and
  formation of HEP collaborations, first joint
  SP-NHMFL YBCO coil
• Definition of the key problems of the conductor
  technology and formation of a focused attack on
  the issues
• New benchmark for a superconducting magnet
  26.8T
• 2008 parallel paths for YBCO and 2212 now
  clearly warranted
• 32 T all superconducting MRI proposal rejected on
  technicality (too many from FSU)
• Multilab 2212 proposal submitted from Fermilab
  (PIs Larbalestier and Alvin Tollestrup
  BNL/FNAL/LANL/LBNL/NHMFL/NIST
• New world record small magnets of 2212 (32T) and
  YBCO (33.8T)
• 2009 recognition that our RD program was
  indeed promising
• 2M MRI for 32 T awarded (10/09 start, PIs
  Markiewicz, Larbalestier and Steve Julian)
• 4M awarded by DOE-HEP over 2 years to evaluate
  the coil-readiness of Bi-2212 (6/09 start) PIs
  Larbalestier and Alvin Tollestrup (Fermilab) with
  multilab efforts at BNL, FNAL, LANL, LBNL, NHMFL
  and NIST

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Bi-2212 round wire coil (Trociewitz, Weijers, DCL
on Oxford 2212) conductor reached 32.1 T in 31 T
background
before HT
after HT

• coil specs
• 15 mm ID, 38 mm OD
• 100 mm high
• 10 layers, 750 turns, 66 m
• DB 1.2 T at 31 T
• L 1 mH

• slight discoloration of braid at enclosed
  feed-through
• regular HT, no visible leaks

15mm spiral results

• first HTS wire-wound coil to go beyond 30 T