Briefs submitted for the TB to approve Tesla

1

• Briefs submitted for the TB to approve Teslas
  long lead items
• Cold Mass Forging
• Super conductor wire

2
Technical Board approval for The Cold Mass
forging
Location of the Cold Mass in the AFC module
3
Dimensions and material of the Cold Mass
Coil size- Latest agreement on the conductor
size with Tesla is- Formvar insulated- 1.57 x
1.00mm With a 0.1mm thick interlayer insulation,
this makes the coil size- 210 x 84mm As long
as the forging provides a generous machining
allowance, there shall be no risk in this
respect. Material- We specified Aluminium
T6061 Tesla propose the same material. Material
fully compliant!
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Forging dimension as specified in Teslas
purchase order
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Profile of the Tesla Bobbin forging
Cold mass profile as per AFC Technical Spec
Average machining allowance is 9 10mm on both
surfaces. This is acceptable!
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Details of Teslas procurement related QA / QC
documents are in Attachment 1 and are summarised
in the table below
Item Drawing no. Material Specification Lead Time Preferred Vendor Location Fall Back Vendor Acceptance Criteria
Super-conducting Wire Tesla Part no, 156-A3000P01 See below 7 months European Advanced Superconductors GmbH Germany none CoC, chemical analysis and suppliers inspection report to Tesla purchase spec
Bobbin Forging Tesla Drg no. 156-D2203 6061-T6 12 weeks Anvil Alloys Ltd U.K UK none CoC, mill report analysis and suppliers inspection report to Tesla purchase spec
Cryocooler Tesla Part no, 156-A3300P03 PT415 (Cryomech Part No.) 18 weeks Cryomech Inc USA none CoC
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Super-conductor wire
What was in the AFC Module Conductor
Spec Conductor size 1.65x1.05 over insulation
Coil width 210mm Thickness 84mm Turns/layer
127 Layers 76 Helium volume 9.5
litres/coil Inter-layer insulation
0.1mm Ic760A(5T,4.2K)
What Tesla offers and requires our
approval- Conductor size 1.52 x 0.95mmFormvar
insulated- 1.57 x 1.00mmwith 0.1mm interlayer
insulation Coil width 210mmCoil thickness
84mm Turns / layer- 132No. of layer-
76 Helium volume 9.5 litre / coil Ic686A(5T,4.5K)

Obviously Teslas proposal is different to that
specified in our AFC technical specification
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Material composition and details of the proposed
super-conductor wire
Type F 174 Dimension bare 1.52 x 0.95
mm² Formvar insulated 1.57 x 1.00 mm² Consisting
of 174 NbTi filaments In a Cu-matrix Ratio Cu
NbTi abt. 4.0 1 Core conductor with
Nb-barrier Core Alpha abt. 0.45 Corner radius gt
0.20 Filament diameter abt. 48 µm Ic at 4.2 K
0.1 µV/cm, 5 T 686 A RRR gt 80
A meeting was held on the25th of July and
following Elwyn Baynhams assessment of the
proposed wire size (see Appendix 2), we have
recommended the acceptance of the type F174
wire Tesla confirmed that the above change does
not have any implication on cost or delivery
schedule
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Attachment 1 The following documents are
submitted with this review brief- Word
document- Final Customer Approval by
Tesla PDF document- Purchasing Plan by
Tesla PDF document- General Purchasing
Specification by Tesla
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Attachment 2 Elwyn Baynhams preliminary
assessment of the MICE specified super-conductor
wire with that proposed by Tesla
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Attachment 2

P1 of 4
AFC Module Conductor Spec Spec Conductor
1.65x1.05 over insulation Ic760A(5T,4.2K) Coil
width 210mm Thickness 84mm Turns/layer 127 Layers
76 Helium volume 9.5 litres/coil Inter-layer
insulation 0.1mm
12
Attachment 2

P 2 of 4
AFC Module Conductor Spec Conductor Options Stay
with Original Specification 1.65x1.05 with 0.1mm
inter-layer insulation Tesla tolerance
specification /- 0.01mm Turns/layer 127
turns/layer should be maintained as specified At
nominal conductor size the coil width will be
209.55mm This is an allowance of 3.5 microns
/turn for conductor spacing Tesla should confirm
that in their experience this is sufficient
margin to wind 127 turns in each layer At
conductor max size 1.650.01mm it is not possible
to fit 127 turns in the layer Tesla should
indicate what they propose to do in this case to
meet the specification Increase the coil channel
width what would be required? Contd on next
slide
13
Attachment 2

P 3 of 4
AFC Module Conductor Spec Conductor Options -
contd Stay with Original Specification 1.65x1.05
with 0.1mm inter-layer insulation Tesla tolerance
specification /- 0.01mm Coil thickness 76 layers
at 1.050.1mm interlayer insulation thickness (
we believe the interlayer insulation requirement
was accepted by Tesla) Spec was 76 layers at 84mm
thickness For this conductor option at nominal
size 76 layers x 1.15 87.4mm For this conductor
at max size 76 layers at 1.16
88.2mm Consequences/impact The increased
thickness will move the coil centre radially
outwards and this would require an increase in
the operating current of 1Amp ( no real
effect) The increased radial thickness would
reduce the Helium volume in a single coil by 20
at the max size this we are concerned about
relaxing at this stage because we do not have yet
the detailed design calculations from Tesla to
confirm heat loads, coil losses during ramping
etc Both of these issues were discussed at the
meeting in September 07 and communicated to Tesla
in a memo at the beginning of May 2008 At both
instances we requested that Tesla should give
their assessment of the coil thickness build up
and possible variations
14
Attachment 2

P 4 of 4
AFC Module Conductor Spec Conductor Options
2 Change the conductor size to1.57x1.00 with
0.1mm inter-layer insulation Tesla tolerance
specification /- 0.01mm Ic686A(5T,4.5K) Turns/la
yer 132 turns/layer should be considered as new
spec At nominal conductor size the coil width
will be 207.24mm This is an allowance of 20
microns /turn for conductor spacing At max
conductor size the coil width will be 208.56mm
This is an allowance of 10 microns /turn for
conductor spacing which seems realistic Tesla
should comment Coil thickness Coil thickness is
maintained to specification Margins spreadsheet
shows that the operating point is 75 along the
load line with temperature margin
1.5K Operating current would be 200.3 A for
200Mev/c