From Ions to Wires to the Grid

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From Ions to Wires to the Grid
Ken Marken Superconducting Technology Center Los
Alamos National Laboratory

• The Transformational Science of LANL Research in
  High-Tc Superconducting Tapes and Electric Power
  Applications

2
Overview

• The Superconductivity Technology Center at Los
  Alamos has pioneered the development of coated
  conductors high-temperature superconducting
  (HTS) tapes which permit dramatically greater
  current densities than conventional copper cable,
  and enable new technologies to secure the
  national electric grid.
• Sustained world-class research including concept,
  demonstration, tech transfer, and ongoing
  industrial support has moved this idea from the
  laboratory to the commercial marketplace.

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STC Organization

• Center Leader Ken Marken
• HTS RESEARCH DEVELOPMENT TEAM
• Leonardo Civale, Team Leader
• WIRE DEVELOPMENT TEAM
• Terry Holesinger , Team Leader
• POWER APPLICATIONS TEAM
• Steve Ashworth, Team Leader
• ELECTRONIC MATERIALS DEVICES TEAM
• Quanxi Jia, Team Leader
• 31 paid staff, 40 including contract
  affiliates
• 6M HTS program, 9M center total

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OE HTS Program Breakdown at LANL
Four agreement areas with 3 to 5 subtasks each
Materials Research 1.1 Magnetic Flux Pinning 1.2 HTS Property Characterization 1.3 Microstructural Characterization 1.4 IBAD Research Process Development 2.1 Buffer Layer Development 2.2 Thick Films Pinning (PLD) 2.3 Co-evaporation 2.4 Continuous Processing
CRADAs for 2G Wire 3.1 SuperPower CRADA 3.2 AMSC CRADA 3.3 MetOx CRADA 3.4 STI CRADA Power Applications 4.1 AC Loss Minimization 4.2 Cable Readiness Reviews 4.3 Advance Cable RD 4.4 High Current Test Facility
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A very general outline

• Motivation/Background YBCO coated conductor RD
• Textured templates for coated conductor
• YBCO performance issues
• Applications issues and demonstrations

6
DOE-OE Mission Space

• The Office of Electricity Delivery and Energy
  Reliability (OE) has the task to lead national
  efforts to modernize the electric grid, enhance
  security and reliability of the energy
  infrastructure, and facilitate recovery from
  disruptions to energy supplies
• HTS development has played a key role in this
  program since its inception.
• Two key components of the program are HTS
  materials development, and HTS applications
  demonstrations.
• Benefits of HTS that drive this long term
  investment
• Superconductors are inherently high current
  materials
• Superconductors are inherently low loss materials
• Superconductors are inherently fault current
  limiting (fast switching from low to high Z)

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A brief history of DOEs HTS for electric power

• DOE HTS program started in 1988 with formation of
  3 Pilot Centers (ANL, LANL, ORNL), 1st peer
  review in 1989
• Early years included bulk materials and thin
  films for electronics (electronics cut from
  program in 1992)
• YBCO
• High Jc in thin films
• Low Jc in bulk, wires
• Coated conductor program began in 1995 (200
  A/cm-w on metal at LANL)
• First meter length of coated conductor in 1997
• BSCCO
• Reasonable Jc in very first wires
• Quickly evolved into multifilamentary tapes, wire
  program started in 1990
• Prototypes
• Earlier SPI projects included transformer,
  motors, generators, cables, FCL
• Present SPE projects include only cables and
  Fault Current Limiters

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High Jc motivates the strong interest in YBCO
YBCO Tape, Tape-plane, SuperPower
1,000,000
(Used in NHMFL tested Insert Coil 2007)
At 4.2 K Unless
YBCO Tape, _ Tape Plane, SuperPower
(Used in NHMFL tested Insert Coil 2007)
Otherwise Stated
YBCO Bc
Bi-2212 non-Ag Jc, 427 fil. round wire,
Ag/SC3 (Hasegawa ASC-2000/MT17-2001)
YBCO Bab
100,000
Nb-Ti Max _at_1.9 K for whole LHC NbTi
strand production (CERN, Boutboul '07)
Nb-Ti Nb-47wtTi, 1.8 K, Lee, Naus and
Larbalestier UW-ASC'96
1.9 K LHC
Nb3Sn Non-Cu Jc Internal Sn OI-ST RRP
Nb-Ti
1.3 mm, ASC'02/ICMC'03
10,000
Nb3Sn Bronze route int. stab. -VAC-HP,
non-(CuTa) Jc, Thoener et al., Erice '96.
Critical Current Density (non-Cu), A/mm² 
Nb3Sn 1.8 K Non-Cu Jc Internal Sn OI-ST
RRP 1.3 mm, ASC'02/ICMC'03
2212
Nb3Al RQHT2 At. Cu, 0.4m/s (Iijima et al
round wire
1,000
2002)
Nb
Al
2223
3
Bi 2223 Rolled 85 Fil. Tape (AmSC) B,
2223
UW'6/96
RQHT
tape B_
tape B
Bi 2223 Rolled 85 Fil. Tape (AmSC) B_,
UW'6/96
100
MgB2 4.2 K "high oxygen" film 2, Eom et
Nb
Sn
al. (UW) Nature 31 May '02
3
MgB
2
MgB2 Tape - Columbus (Grasso) MEM'06
1.8 K
film
MgB
Nb
Sn
Nb
Sn
2
3
3
tape
ITER
Internal Sn
10
0
5
10
15
20
25
30
35
Applied Field, T
Courtesy Peter Lee http//magnet.fsu.edu/lee/
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Enabling Factors for HTS Commercial Success

• Cost/Performance ratio (typically /kA-m) is the
  key enabler
• Cost reductions
• Higher rate
• Simpler architecture
• Larger scale manufacturing
• Performance improvements
• Higher Jc
• Thicker superconducting layers
• Process uniformity for superconductor homogeneity
• For applications requiring magnetic field
  generation, engineering current density
  improvements are needed

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Worldwide Status of Coated Conductors
Organization Organization Processing Long Tape Long Tape Long Tape Short Tape
Organization Organization Processing IcA/cm-w Lm Ic x LAm Icmax A/cm-w (JcMA/cm2)
SuperPower USA YBCO (MOCVD) - MgO (IBAD) 178 1311 233,810 830 (2.9)
SuperPower USA YBCO (MOCVD) - MgO (IBAD) 302 630 190,260 830 (2.9)
Fujikura Japan GdBCO (PLD) - GZO (IBAD) 350 504 176,023 540 (2.2)
SWCC Japan YBCO (MOD) - GZO (IBAD) 310 500 155,000 370 (2.5)
SRL Japan YBCO (PLD) - GZO (IBAD) 213 245 52,185 480 (1.2)
AMSC USA YBCO (MOD) - NiW (RABiTS) 250 200 50,000 560 (4.0)
Sumitomo Japan HoBCO (PLD) - NiW (RABiTS) 205 200 41,000 316 (1.8)
Bruker HTS Europe YBCO (PLD) - YSZ (IBAD) 253 100 25,300 574 (3.6)
Chubu Japan YBCO (MOCVD) - GZO (IBAD) 93 203 18,879 294 (1.6)
SRL Japan YBCO (MOD) - GZO (IBAD) 250 56 14,000 735 (2.4)
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A very general outline

• Motivation
• Textured templates for coated conductor
• YBCO performance
• Applications issues and demonstration projects

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Materials challenge number one
The HTS materials of interest, Y1Ba2Cu3Oy (YBCO),
are brittle ceramics with stringent demands on
grain alignment for high current transport.
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LANL approach to a solution textured templates

• The LANL concept for producing a flexible, robust
  wire with YBCO is based on producing a
  film-textured surface on a random,
  polycrystalline superalloy tape.
• Using our patented Ion-Beam Assisted Deposition
  (IBAD) technology, near single-crystal quality
  oxide layers of MgO may be produced in arbitrary
  lengths (gt 1 km), suitable for subsequent
  deposition of HTS or other technical materials.

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IBAD Ion Beam Assisted Deposition
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RHEED measures texture evolution
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Effect of Ar dose on MgO texture
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IBAD-MgO and IBAD-GZO comparison
LANL has demonstrated 540 meters/hr with 9.5
texture in IBAD-MgO Single pass(14 cm dep
zone) Single ion source 1500 V, 500 mA
1
1 Physica C, 392, 777, 2003
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IBAD-MgO and IBAD-YSZ comparison
Rapid texture development makes IBAD MgO a viable
technology for coated conductors
Hammond et al., Appl. Phys. Lett. 71, 2955
(1997). Arendt et al., MRS Bulletin 29 (8), 543
(2004).
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Materials challenge two reducing complexity
A simpler architecture can reduce processing
steps and/or manufacturing costs

• Barrier layer Al2O3 preventing mobile ionic
  species from inter-diffusion
• Nucleation layer Y2O3 extending the thickness
  range of IBAD MgO layer
• IBAD MgO inducing epitaxial texture
• Homo-epi MgO relaxing the strain, reducing the
  damage, acting as a barrier, and improving the
  texture
• Buffer layer (LaMnO3 or SrTiO3) reducing
  lattice mismatch between MgO and YBCO, and
  passivating the MgO surface

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Demonstrated 4 and 3 intermediate layers
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4 intermediate layers with MOCVD YBCO
SuperPower has successfully grown RE123 films by
MOCVD on our simplified IBAD MgO templates
MOCVD RE123
LMO
Homo-epi IBAD MgO
YAlO
Hastelloy
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4 intermediate layers with MOCVD YBCO
Minimal interface mixing is maintained by using
YAlO as both diffusion barrier and nucleation
layer
IBAD MgO template using single layer of YAlO to
replace bi-layer Y2O3 and Al2O3 is compatible
with MOCVD process for HTS films.
YAlO
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Demonstration of 4 intermediate layers
High performance of RE123 films by MOCVD confirms
the effectiveness of YAlO as both barrier and
nucleation layer
Angle (deg.)

• Overall critical current density values are
  similar regardless of deposition techniques used
  (PLD 2.9 MA/cm2 MOCVD 2.0 - 3.2 MA/cm2)
• Typical ? values for PLD and MOCVD films are in
  the same range of 0.5 - 0.6
• Defects well aligned with crystallographic axis,
  very little c-axis peak

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Demonstration of 3 intermediate layers
PLD -YBCO
LMO or SZO
IBAD MgO
YAlO
Hastelloy
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IBAD Technology Transfer
(2003-2006) LANL made multiple visits to
SuperPower to transfer IBAD MgO
(2000) LANL achieved 180 A/cm-w on IBAD MgO
(2001) LANL obtained first IBAD MgO meter CC
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Aside an alternate textured template
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A very general outline

• Motivation
• Textured templates for coated conductor
• YBCO performance
• Applications issues and demonstrations

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Materials challenge 3 self-field Jc decreases
with thickness
And this dependence is strikingly similar for a
variety of deposition processes
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Enhancement of Jc at the interface is now clear
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Recipe for interfacial enhancement
77K
MOD films Kim, et al.Supercond. Sci. Technol.
19, 968 (2006) Rupich, et al.2006 HTS Peer
Review Zhang, et al. IEEE Trans. Appl.
Supercond.
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Jc decreases when lattice mismatch is eliminated
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Jc increases when MD are restored
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Ion milled samples showed correlation between MD
and Jc(t)
Foltyn, Nature Materials, V6, 631, 2007
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Highest Jc and Ic obtained in multilayers
Depositing interlayers of CeO2 between YBCO
layers restores MDs and Jc in self field
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Materials challenge 4 anisotropy in Jc
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Jc(B,?,T) depends on pinning mechanisms and
regimes
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Pinning defects and Jc(?) vary with deposition
method
Comparison of the angular dependence of different
film types at 1 T shows that the situation is
complex and no single orientation can tell the
whole story
TEM image of a PLD film on STO buffered MgO
single crystal
Foltyn, Nature Materials, V6, 631, 2007
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High critical currents using synergetic tailoring
of self-assembled defects in YBa2Cu3O7 BaZrO3
B. Maiorov et al. Nature Materials 8 (2009)
DOI 10.1038/NMAT2408

• We investigate and understand the synergetic
  mechanisms of vortex pinning by columnar defects
  and nanoparticles.
• Varying PLD growth kinetics alters defect size
  morphology
• This allows tuning of the pinning landscape from
  random particles to oriented columnar defects
• The publication shows world-record Ic-w(75.5K,
  1T) in thick films
• 2.3 µm thick with gt200 A/cm

Illustration or figure here
Nanorod length increases splay decreases with
higher Tdep Moiré fringes indicate continuous
rods Statistics taken from 400x400 mm2
micrographs Red lines in right panel b indicate
possible vortex configurations
Optimization studies done on 1 µm
films Deposition temperature of 795C was
optimum 5 Hz PLD gave best avg. angular
performance These parameters were used to deposit
a set of thick films which resulted in champion
Ic values
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Structural changes with growth dynamics in
YBa2Cu3O7 BaZrO3

• Nanorods length increases and splay decreases
  with higher Tdep
• Moiré fringes indicates continuous rods
• Statistics taken from 400x400 mm2 micrographs
• Red lines in central panel b indicate probable
  vortex configurations

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As previously found in plain YBCO, we confirmed
the presence of Moiré fringes at the interface in
BZO-doped YBCO films.
This points to misfit dislocations as the origin
of the interface Jc enhancement also in BZO-doped
YBCO
plain YBCO (PR 2006)
75.5K, self field
TEM by Haiyan Wang, Texas AM
BZO-doped YBCO
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Tdep optimization for different film thicknesses
BZO-YBCO --2008
75.5K, self field
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Tdep optimization for different film thicknesses

BZO-YBCO --2008
There is still room for increase of Jc(sf) in
thick films. We continue to push up the curve!
75.5K, self field
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Jc and Ic continue to improve

• Achieved Ic(sf)1500 A/cm)
• Raised Jc(sf) to a level previously obtained only
  with multilayers, but with far superior in-field
  performance.

Ic-w gt 400 A/cm (_at_1T, 75K) Ic-w(max) 500A/cm
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A very general outline

• Motivation
• Textured templates for coated conductor
• YBCO performance
• Applications issues and demonstrations

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Transport loss in two parallel RABiTS Tapes
Substrate influence
Current
Double field in substrate Both conductors same
field
Upper conductor Increased field Lower
conductor Decreased field
Substrate shielded from field
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LIPA Transmission level cable

• The world's first HTS power transmission cable
  system operating at 138 kilovolts since April
  2008 offers reduced losses and right-of-way
  footprint compared with conventional cables.
• Installed in the Long Island Power Authority
  grid, it is capable of carrying 574 megawatts,
  enough to power 300,000 homes.
• The three cables shown entering the ground can
  carry as much power as all of the overhead lines
  on the far left.
• The three separate cables contain high
  temperature superconductor developed by LANL in
  collaboration with American Superconductor Corp.
• The cable project was cost shared by DOE Office
  of Electricity, American Superconductor, Nexans
  and LIPA.

(Photo courtesy American Superconductor Corp.)
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AMSC Siemens FCL

• Fault current limiters based on superconducting
  materials act as high-voltage surge protectors
  for power grids
• LANL is a partner in a FCL project cost shared
  by DOE - Office of Electricity, American
  Superconductor, Siemens, Nexans Southern Cal
  Edison
• Based on high current density YBaCuO films with
  very fast switching between superconducting and
  resistive states.
• Photo at left is a 2.25 MVA, 7.2 kV prototype
  tested in 2007.
• The system under development will be an in-grid,
  three phase, 138 kV Fault Current Limiter

Artists rendering of the final FCL installation
planned for 2012 in Southern Cal Edisons Valley
Substation near Riverside, California.
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Summary

• Progress continues toward longer lengths and
  higher performance in YBCO coated conductors
• Steady series of record values in Ic X L over the
  last couple years
• Friendly competition between key manufacturers in
  US, Japan, Europe
• Cost/performance ratio remains 30-50x too high,
  but steady reductions continue
• Simpler conductor architectures
• Thicker YBCO films
• Key need at this time is more robust, higher
  reliability manufacturing processes (process
  control)
• Key cable application demonstrations continue