Proposed TF Joint Design

C Neumeyer

2/26/9

Notes:

1) Several concepts included are based on ideas developed by R Woolley2) No analysis has yet been performed to justify the design

Features (1)

• Bolted lap joint inner leg to vertical flag– Joint area ~ 2x inner leg conductor area after accounting for bolt– Bolts threaded into steel blocks within inner leg conductor allowing high

force– Bolt in joint region located where J ~ 1/2 of peak value, peak J ~ same as

main inner leg– Bolt in joint region applies load through shoe to distribute force– Joint pressure due to bolt at joint region alone > 2ksi, ~ same as magnetic

pressure– Gap between contact surfaces on flag ensures proper current flow region

and causes outer bolts to contribute to pressure at electrical joint– Shoulder bolts serve to react vertical force, requires high precision

machining or special bolt concept– Flag cross section equal to inner leg cross section– G-10 fins imbedded between turns over joint region and slightly beyond

Features (2)• Radial flag extension

– Flag shape is constant tension to eliminate development of in-plane moments

– Flag cross section equal to inner leg cross section

– Flex section reduces transmission of moments to joint due to small in-plane and out-of-plane deflections and allows for some assembly tolerances

– Flex section resiliant to TF forces, needs evaluation against bucking due to out-of-plane forces

• In-plane flex joint– Two parallel sections with 50% fill factor maintain total cross section

same as inner leg– Flex joint accomodates axial thermal growth, equally split top and bottom

flex– Flex section resiliant to in-plane forces (won’t buckle)

Features (3)• Flag box

– Flag wrapped in Kapton, close fitting to G-10 insulating blocks– Must accommodate thermal expansion in toroidal, vertical, and radial directions– Transmits in-plane load back to TF inner leg conductor via umbrella lid and bolting into

turns– Transmits out-of-plane load to VV via umbrella lid

• Flag box attachment ring– Connects flag boxes to umbrella lid

• Umbrella lid– Transmits torsional loads from inner leg and out-of-plane loads on flags to VV– Shoulder bolts and belleville washers allow small axial expansion of inner leg

bundle etc. w.r.t. VV, top and bottom

• G-10 torque ring– Transmits torsional loads from inner leg to umbrella lid– Transmits vertical loads on radial flags to inner leg turns– Insulates individual turns from umbrella lid

Basis (1)Filament Trajectory

0.0000

0.5000

1.0000

1.5000

2.0000

2.5000

3.0000

0.000 1.000 2.000 3.000

r(m)

z(m)

Tension

-2.00E+04

0.00E+00

2.00E+04

4.00E+04

6.00E+04

8.00E+04

1.00E+05

1.20E+05

0.000 1.000 2.000 3.000

r(m)

Tension (N)

Section Total Fr Total FzInner leg 0.00E+00 6.34E+04Flag -8.89E+04 2.59E+04Flex -2.43E+04 5.85E+04Outer_1 0.00E+00 5.17E+03X1_2 1.24E+04 0.00E+00Outer 1.30E+04 4.20E+04

Basis (2)Chord length 0.0338 m 1.3317 inRadius to chord 0.1933 mTurn-Turn insulation 0.0016 m 0.0640 inExtra gap 0.0068 0.2677 inTotal gap 0.0084 m 0.3317 inJoint width 0.0254 m 1.0000 inBundle conductor area 0.0029 m^2 4.4522 in^2Inner flag dR 0.1131 m 4.4522 inInward magnetic force per unit length 5.23E+05 N/m 2.99E+03 lbf/inInward magnetic pressure 2.06E+07 N/m^2 2.99E+03 lbf/in^2Outward radial force from constant tension segment6.36E+04 N 14306Flag bolt size 0.0127 m 0.5000 inThreads/in. 20 20Pitch diameter 0.0119 m 0.4675 inTensile area 1.03E-04 m^2 0.1600 in^2Tensile Yield strength 1.28E+09 N/m^2 1.85E+05 lbf/in^2Tensile allowable (2/3 yield) 8.50E+08 N/m^2 1.23E+05 lbf/in^2Max axial load/bolt 8.78E+04 N 19728 lbfFraction of allowable axial load 1.00 1.00Axial load/bolt 8.78E+04 19728Thread engagement length 0.0127 m 0.5000 inPull-out shear area 3.55E-04 m^2 0.5508 in^2Pull-out shear stress at max axial load/bolt 2.47E+08 N/m^2 35819 lbf/in^2Pull-out Shear allowable (60% tensile) 5.10E+08 N/m^2 74000 lbf/in^2Pull-out shear safety factor 2.1 2.1Joint area ratio 1.50 1.50Joint area 4.31E-03 m^2 6.6783 in^2Joint dZ 1.75E-01 6.8746Inward bolting pressure 2.04E+07 N/m^2 2.95E+03 lbf/in^2Ratio bolting pressure/magnetic pressure 0.99 0.99Total inward pressure at full current 4.10E+07 N/m^2 5.94E+03 lbf/in^3Contact resistivity at zero current 0.43 microohm-in^2Contact resistivity at full current 0.29 microohm-in^2

1” joint widthJoint area 1.5x inner cond csa 0.5” bolt at ~ 20ksi~ 3ksi bolting pressure~ 3ksi magnetic pressure

QuickTime™ and aVideo decompressor

are needed to see this picture.

QuickTime™ and aVideo decompressor

are needed to see this picture.