NCSX TF Coil Conductor FDR 5/17/05 1

NCSX

Michael Kalish

NCSX TF Conductor

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NCSX

Outline

• Requirements• Design• Calculations• Specification, SOW• Procurement

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Requirements

• Is the material specified correctly?• Are the yield and ultimate specified for the

conductor appropriate?• Is the hole big enough?• Is the copper cross-section big enough?

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NCSX

TF Coil Winding Pack

• Winding Pack 3x4• Extruded Conductor

Wound “Hard Way”• Center Hole LN2 Cooled• Each Layer Requires 88’,

100’ to 110’ supplied• 4 Spools Required per Coil

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Drawing / Tolerances

• Discussions with Vendor Indicate Tolerances Reasonable

• Edge Radius results from R&D

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NCSX

Winding Pack Insulation Scheme

3/8” Groundwrap on outboard leg

1/8” Groundwrap on inboard wedging leg

• Inner TF leg ground wrap thickness is 1/8”• Outer leg of TF coil allows for the use of tough 3/8” ground

wrap• Insulation thickness can accommodate potential .020 inch

tolerance build up easily

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NCSX

Conductor Material Properties

• Yield Strength– Yield Strength shall be 26,000 psi min. (180 MPa) to 30,000 psi

max. (0.5% extension under load) at room temperature– At LN2 Temperature 225 MPa Min.

• Tensile Strength– Ultimate Tensile Strength shall be 36,000 psi min. (248 MPa) with

a minimum extension under load of 25% at room temperature– At LN2 Temperature 340 MPa Min.

• Hardness– The conductor shall have a Rockwell Hardness F between 60 and

70 at room temperature. If there is a discrepancy between the Hardness requirement and the Yield Strength requirement the Yield Strength measurement shall be the governing requirement.

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NCSX

Maximum Conductor Stress

• Requirement + Assumptions showing Highest Conductor Stress

• Half Tesla TF Only Analysis

• Un-bonded assumption• Maximum Stress = 117

MPa

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NCSX

Yield and Tensile Requirement Adequate per Analysis

• Primary Membrane + Bending (PM+PB < 1.5Sm):

σ(PM+ PB) =117 MPa < 225 MPa (1.5Sm)

• General Primary Membrane (PM < 1.0Sm):

σ(PM) = FZ/ACu = 30 MPa <150 MPa (1.0Sm)

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NCSX

Fatigue Requirements Met

• Fatigue (Cumulative Usage Factor, CUF < 1.0)Entering the 2x stress design-basis fatigue curve with an alternating stress of 74 MPa yields an

allowable number of cycles ~100,000 cycles > 13,000 cycles required

σeq(alt) = σalt /{1 - σmean/σut} = 62/{1-55/340} = 74 MPa

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NCSX

Thermal / Hydraulic Analysis Verifies Cross Section and Hole Diameter

• With given cross section and hole size:• Peak temperature and recovery time

calculated for maximum required pulse (0.5 Tesla TF field) for 16.2 kA peak current with a 1.64 second equivalent square wave (ESW).

• Peak temperature rise of the coil is ~3.5 deg.K (~6 deg.R) per pulse

• LN2 system will be pressurized to a min. pressure of 60psi allowing a max temp of 95K for single phase LN2 flow

• Peak temperature insensitive to flow rate• Full recovery to 80 deg.K after ~720

seconds with a 60 psi differential pressure applied.

•Pre-Pulse Temp 80K•System pressure adequate to guarantee single phase flow•Pulse repetition rate shall not exceed 15 minutes

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Procurement

• Cost and Delivery based on preliminary quotes• Cost per Spool

247 lbs per spool x $4.47/lb = $1104• Conductor order for 19 coils + one spool for R&D

Total = $1104 x 77 spools = $85K• Delivery = 60 days

(+shipping for OutoKumpu)