Strand R

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Strand RD
LARP, Berkeley, CA USA, Apr. 26-28, 2006

• E. Barzi for the Materials Group

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Outline

• Overview of FY06 Tasks and budget status
• Progress since Oct. 05 Collaboration Meeting
• Outstanding issues
• FY07 Task schedule

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Superconductor RD
Outline

• Properties of round strands
• How are strand properties affected in cabling
• Measure effect of Lorentz forces
• Effect of conductor properties on magnet
  performance

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FY06 Strand RD Tasks
A possibly improved RRP strand with 54 subel. was
later chosen as LARP workhorse strand for 2006,
with the Conductor Development Program (CDP)
undertaking the RD endeavor of designs with
smaller subel.
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FY06 Tasks and Budget status

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RRP HT Studies
BNL data on 8220 RRP billet
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Prediction of Short Sample Limits
SRS01
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High Field Short Sample Limits
SRS01
BNL Imax 9780 A (490 A/strand) Bpeak 12.4 T
FNAL Imax 9630 A (480 A/strand) Bpeak 12.2 T
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Low Field Short Sample Limits
Transformer test results
Extracted strand test results
BNL IS 575 A to gt1200 A RRR 174 to 355
FNAL IS 587 A to 1287 A RRR 297
SRS01
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Choice of Strand and Cable
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Cabling simulation High Field Jc
Rolled down strand
Strain(d-t)/d
One can find a range of strain where there is a
good correlation of Ic degradation between
extracted and rolled strands
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Filament Size Distributions
28-strand PIT Cable (88.6 packing factor)
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(No Transcript)
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Deff onset for Instabilities
B
PS limit
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Rolled vs. Cabled
PS limit
PS limit
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Filament Merging
Merging cannot be seen through magnetization of
an extracted strand because it is a local effect
RRP Cable cross section
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Observe Merging through Magnetization
PIT- Deformation, but NO merging
RRP- Deformation AND merging
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Min. Iq of RRP LARP strands in low field
Extracted
Cable
Rolled
In cables and extracted strands Is and RRR are
not as reproducible as in round strands.
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New RD Design by OST
Previous design
New design (05)
Newer design (06)
60/61 restack with spaced SEs
120/127 restack with spaced SEs
54/61 restack
The new design has increased Cu thickness between
subelements to reduce cabling impact on
subelement merging.
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FY07 Strand RD Tasks