Evaluation of Left Lay Inner Cable L30B0831 and L3IB00908 for Coil Insulation and Winding Fred Nobre

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Evaluation of Left Lay Inner Cable L-3-0-B0831
and L3I-B00908 for Coil Insulation and
WindingFred Nobrega, Jim Rife 24 February 2005

• Insulation line
• 908 831 insulation and winding
• Summary
• Conclusions

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Cable Insulation Line
Beginning of Cable Insulation Line
Cable Tractor, Counter and Cable Hi-Potter
Take Up Spool
1st and 2nd layers of Kapton Insulation
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Cable L3I-B00908 (908)
Cable 908, insulated about 60 ft after paying out
about 60 ft of bare cable. Difficult to
insulate.   Cable 908, insulated 170 ft, severely
roped near 170 ft mark, several popped strands,
Kapton tension low to prevent cable collapse or
popped strands.   Cable 908, annealed 148 ft
(180 C for 30 minutes). Insulated with the
following observations   - Stiffer, insulated
better than un-annealed 908 - Popped strands more
difficult to put back into place - Using special
flat pliers prior to insulating minimized popped
strands, however in a 15 ft section, 8 small
partially popped strands on wide edge were
observed. They can be put back into lay, but if
missed would likely cause a turn-to-turn short in
the coil.
Special Flat Pliers
Small Partially Popped Strand on Wide Edge of
Cable
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Cable L3I-B00908 (908), continued
Practice wind 908 annealed cable.
Observations 1st turn around return end of coil
inner surface popped strand with 3 out of lay
strands about 12 inches from nose of winding key.
Cable withstood 70 lbs of winding tension. 908
summary -   Never wound un-annealed cable, too
unstable -   Annealed cable had better cable
insulation properties but still popped strands
during practice winding
908 Popped and Out of Lay Strands
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L-3-0-B0831 (831)
Cable 831, insulated 233 ft, required constant
manipulation using flat pliers at about 4
locations along insulation line. Ended with
severe and un-repairable roping of cable. Many
out of lay strands after insulation. Used low
Kapton wrapping tension, which caused Kapton to
be fluffy on cable.   Note Cable 831insulated
slightly better than cable 908 un-annealed during
cable insulation. Cable 831 is spongy in middle
of cable and can be put back into lay using flat
pliers.   Practice wind of 831 un-annealed.
Observations 1st turn of return end key, popped
strand on inner surface, continued to lead end
and popped strand on inner and outer surface of
cable. Back wound and repaired cable using
pliers. It may have worked but not sure, plus the
pliers can cause pinholes in the insulation.
Return End 2nd Turn, (not 831, 908 cable)
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L-3-0-B0831 (831), continued
Back wound cable to the beginning of reel and cut
off about 9 ft of cable and repeated practice
winding. 1st turn, return end, slight pop of
strand, lead end popped strand was pushed back
into place and it stayed however, outer surface
of cable just past the turn had several popped
strands and a bulge in the cable. Continued to
wind even though cable was without insulation
(bare cable) and made second turn on return end.
Strand popped slightly worse than cable with
insulation.
Inner Coil Lead End 1st Turn, (not 831, 908
cable)
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L-3-0-B0831 (831), continued
Cable 831 un-annealed winding summary - Lead
end 1 turn - Return end 2 turns, 1st insulated
cable, 2nd bare cable - All turns popped strands
at nose of winding key.   Annealed 140 ft of 831
(180 C for 30 minutes).   Attempted to insulate
annealed 831. Observations   Cable was stiffer
but unruly and difficult to put strands back into
lay with pliers. Cable condition was made worse
by annealing. Cable was not insulated.
Model Magnet Coil, HGQ06, Left Lay cable
Model Magnet Coil, HGQ06, Left Lay cable, Popped
Strand on Return End
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Conclusions
What we have Spool approx (m)
831               700 908 1200
909               700 What we need 4 inner
coils for last LHC cold mass MQXB19 that
typically requires 5 unit lengths (900 m) of
inner left lay cable. Assumes 20 attrition.
  Conclusions - Remaining inner cable 831, 908
and 909 are too unstable to wind coils. -
Annealing improved 908 cable stability but not
enough to wind coils.