aries-at toroidal field (tf) and poloidal field (pf) coils

ARIES AT Project Meeting - Princeton, NJ 18 Sept 00

1

ARIES-AT Toroidal Field (TF) and Poloidal Field (PF) Coils

Tom Brown, Fred Dahlgren,

Phil Heitzenroeder (PPPL)

September 18, 2000

ARIES AT Project Meeting - Princeton, NJ 18 Sept 00 2

ARIES AT TF and PF Design The ARIES AT TF and

PF systems are based on YBCO high temperature SC.

The coil configuration permits full replacement of the blanket/shield modules.

Design is based on Ron Miller’s strawman ver. 306 & Chuck Kessel’s optimized PF system.


ARIES-AT Configuration Features

• High T SC TF

• No structure between TF outer legs:

• Permits blanket/shield/ divertor module removal.


Mechanical Arrangement

Double Pan.

TF WindingVV

Blanket/Shield/PFC Module

TF case

PF coils

Solenoid


5 cm inner case added to TF structure

TF Inboard/Outboard Case Detail

Case structure built up to increase out-of plane stiffness


5 cm inner shell added to TF inboard leg

VV inner radii set at 2.83 m per strawman (ver 306)

Details of the VV, blanket/shield and div module has not been updated in the TF Pro/E models

Inboard Radial Build


Configuration Details


TF System 16 coils B0=5.9 T @R0=5.20 m 9.6 Mat / coil 2400 T/coil; double pancakes Wedged support YBCO Hi T S/C @75K on Inconel

strip Bmax @ S/C=11.1 T Wound construction

– Permits grading; easier fabrication; better field orientation for higher J

Stiffening ribs

Intercoil Structure


TF Coil Case & Lead Details

• One coil case (shown) is configured for power leads.

•The other 15 coils are configured for coil to coil connections.

Leads


TF Coil to Coil Bus Connections

Input lead details Coil-coil connection details


Exploded View of Case Assembly

Total Weight of a Single TF coil is 64 metric tons


TF Coil Winding Double pancakes will be wound into the coil case channel via

two spools which are sized to limit conductor strain to <0.2%.


TF Superconductor

•2 pancakes per coil; 20 turns per pancake

•Each turn has 20 x 3 “sub turns” for a total of 2400 turns/coil.

•I / sub turn = 9600 kAt/2400 t = 4 kA

•Jsc=100 kA/sq. cm (10 micron thick film layer assumed). Strain limit 0.2%.

•Superconductor is conduction cooled by case; case is cooled by LN2.

Inconel strip

YBCO Superconductor Strip Packs (20 layers each)

8.5 mm

CeO2 + YSZ insulating coating(on slot & between YBCO layers)

430 mm


Total Field at

TF Conductor


Radial Field at TF Conductor

Worst Case field perpendicular to SC in Inner leg : Bmax ~ 2.288 T @ BT=11.1T


Vertical Field at TF Conductor

Worst Case Field perpendicular to sc in horizontal leg region: ~Bmax ~5.4 T @ JT=100kA/sq.cm


Conductor Operating Point

Max. B-perp. For TF at 75K ~3.8 T

Bmax., TF

Bromberg and Tekula, “Options for the Use of High Temperature Superconductor in Tokamak Fusion Reactor Design” Jallow., TF=100 kA/sq. cm

Max. B-perp. For PF at 75K ~6 T (@50kA/sq.cm.)


TF Load Patterns

Out of Plane

In Plane


Nastran TF Coil/Case Model (reinforced)

Added inner Case Wall (100mm)

Increased Outer Case Radial Depth (950mm)

Increased Case Wall Thickness (160mm)


Vertical TF Displacements due to Combined Loading (preliminary model)


TF Displacements due to Combined Loading


Coil Strain Due to Combined Loading(maximum principal - preliminary model)

Max.Pr..Strain

7.7%


Coil Strain due to Combined Loading (MaxPrinc.) w/Reinforced Case


In Plane + Out of Plane Max. Pr. Stress


In Plane + Out of Plane Tresca Stress On the Case -w/Reinforced Case.


Poloidal Field SystemCoil R Z I

Number (m) (m) (MA)1 2.25 0.250 -0.6202 2.25 0.750 -1.0533 2.25 1.250 -1.513

OH 4 2.25 1.750 -1.5235 2.25 2.250 -0.6656 2.25 2.750 1.1847 2.25 3.250 3.360

OH

89 10 11 1213

14

8 3.25 5.750 6.3489 3.75 6.000 6.518

Ring 10 5.25 6.300 4.810Coils 11 5.75 6.250 3.643

12 7.50 5.650 -3.27613 8.00 5.400 -5.87714 8.50 5.100 -8.624


Poloidal Field Coil DesignUses YBCO / Inconel

conductor similar to the TF.

J =55 kA / sq. cm

Gl-Polyimide Electrical Insulation

Inconel strip

“N” subturns of YBCO superconducting strip per slot. N varies with coil I requirements

LN2 chill plates (option: pool boiling design)


PF - Radial Fields

Peak Radial Field 9.0 TNeed to re-orient the conductor plane to horizontal.

Peak Vertical Field is8.7 T for PF-14 and 6.9 T @ the conductor.

We will need to reduce thecurrent Density in PF-14.

Peak Radial Field is only7.7 T for PF 12 & 13 and 5.9 T @ the conductor.


PF - Vertical Fields

Peak Vertical Field 9.3 T

Peak Radial Field is only7.7 T for PF 12 & 13 and 5.9 T @ the conductor.

PF-12

PF-13

PF-14


Alternate PF Coil OrientationThe maximum PF-14 normal field component

will be 7 Tesla, @J = 30kA/sq.cm


PF Coil Supports & Stresses

CoilR - Z-A-t ksi Mpa ksi Mpa

1 -0.65 4.94 34.2 1.52 10.51842 -1.05 7.98 55.2 2.27 15.70843 -1.55 10.09 69.8 3.27 22.62844 -1.52 9.002 62.3 4.35 30.1025 -6.65 2.306 16 3.04 21.00226 1.18 0.146 1.01 8.36 57.8727 3.36 9.659 66.8 30.9 213.5518 6.52 38.52 267 43.4 299.9829 4.81 17.25 119 10.7 74.2516

10 3.64 10.49 72.6 7.15 49.457211 -3 39.81 275 38 262.61412 276 40.5 280 39.9 275.9713 -5.88 49.05 339 48.3 334.37414 -8.62 59.65 413 64 442.742

Ip=0 Ip=12.949 MA

•Stresses are OK: allowable is ~600 MPa. based on 0.2% strain limit of SC ,

•We still have to update drawings to coil & support dimensions used in

analyses.

aries-at toroidal field (tf) and poloidal field (pf) coils

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