Briefs submitted for the TB to approve Tesla’s long lead items:

1) Cold Mass Forging

2) Super conductor wire

Technical Board approval for

The Cold Mass forging

Location of the Cold Mass in the AFC module

Dimensions and material of the Cold Mass

Dimension of the Cold Mass as specified in the AFC Technical Spec.

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!

Forging dimension as specified in Tesla’s purchase order

Cold mass profile as per AFC Technical Spec

Profile of the Tesla Bobbin forging

Average machining allowance is 9 – 10mm on both surfaces. This is acceptable!

Details of Tesla’s 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

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

Ic=760A(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

Ic=686A(5T,4.5K)

Obviously Tesla’s proposal is different to that specified in our AFC technical specification

Material composition and details of the proposed super-conductor wire

Type F 174

Dimension bare 1.52 x 0.95 mm²Formvar insulated 1.57 x 1.00 mm²Consisting of 174 NbTi filamentsIn a Cu-matrixRatio Cu : NbTi abt. 4.0 : 1Core conductor with Nb-barrierCore Alpha abt. 0.45 Corner radius > 0.20Filament diameter abt. 48 µmIc at 4.2 K; 0.1 µV/cm, 5 T – 686 ARRR > 80

A meeting was held on the25th of July and following Elwyn Baynham’s 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;

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

Attachment 2

Elwyn Baynham’s preliminary assessment of the MICE specified super-conductor wire with that proposed by Tesla

AFC Module Conductor Spec

Spec

Conductor 1.65x1.05 over insulation Ic=760A(5T,4.2K)

Coil width 210mm

Thickness 84mm

Turns/layer 127

Layers 76

Helium volume 9.5 litres/coil

Inter-layer insulation 0.1mm

Attachment 2 P1 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 1.65+0.01mm 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

Attachment 2 P 2 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 1.05+0.1mm 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

Attachment 2 P 3 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

Ic=686A(5T,4.5K)

Turns/layer – 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

Attachment 2 P 4 of 4