Page 1 TQC Mechanical Model Igor Novitski / Rodger Bossert May 24, 2006 Results of MM#4 and MM#5

Page 2 Goals of Mechanical Models #4 and #5 1.Determine mid-plane shim for collaring. – MM#4 2.Determine shim between collared coil and yoke – MM#5 3.Verify that yoke welding procedure can provide acceptable stress to control spacers and coils. MM #5 – Collared coil assembly only – Made with practice coils #2 and #4 (impregnated at LBNL). Used full round collars. Purpose was to determine mid-plane shim. MM #4 – Included yoke and skin – Made with practice coils #1 and #3 (impregnated at FNAL). Used full round collars. Purpose was to verify yoke welding and determine collar-yoke shim.

Page 3 TQC collared coil. MM #5 – Collared coil only – Made with practice coils #2 and #4 (impregnated at LBNL). Used full round collars. Strain gauges placed on inner surface of inner coil to measure preload during and after collaring. Fuji Film placed at mid-plane to understand relationship between inner and outer layer preload. Procedure: 1.Measure coils azimuthally 2.Key coils with 2 shim sizes (0 and 4 mil) 3.Read strain gauges. 4.Check Fuji film. 5.Re-key with final shim size. 6.Take final readings of strain gauges and collar deflections.

Page 4 MM #5 – First, practice coil #2 was measured individually using reaction tooling in hydraulic press. Measured size was similar, slightly smaller than the nominal size at 60 MPa. Measurements for coil #2 are shown below: The coils were then placed into the collars and keyed.

Page 5 Fuji film placed at the mid-plane showed that inner- outer preload was approximately the same and uniform radially across the cable. With no azimuthal shim Strain gauge readings on coil surface of MM#5 during collaring (inner coil only).

Page 6 With 4 mil azimuthal shim Fuji film placed at the mid-plane showed that inner- outer preload was approximately the same and uniform radially across the cable.

Page 7 Collar deflection measurements using the 5 mil shim are shown above. Deflections are consistent with a preload of about 70 MPa. Based on these results, a 5 mil midplane shim was chosen (2 ½ mils per coil), and a final keying was done using this shim.

Page 8 TQC cross-section. MM #4 – Included yoke and skin – Made with practice coils #1 and #3 (impregnated at FNAL). Used full round collars. Strain gauges were placed on inner surface of inner coil to measure preload increase when yoking. Strain gauges were placed on the control spacers to ensure adequate contact with yoke. Strain gauges were bonded to the skin to verify the expected stress after welding.

Page 9 MM#4 Procedure: 1.Measure collar outside diameter and yoke inside diameter. 2.Install collar-yoke preload shims according to the measurements. 3.Place completed collared coil into yoke. 4.Press yoke until contact with control spacers is made according to strain gauges 5.Weld skin in several passes. 6.Take readings of strain gauges to confirm that contact is made on control spacers, skin stresses are appropriate, and proper coil preload is achieved. Strain at pole is expected to approximately double between the collared and yoke assemblies.

Page 10 Q4-coil1 Q3-coil1 Q2-coil3 Q1-coil3 Gauges bonded to inner surface of inner coils

Page 11 Collar OD and Yoke ID measurement. A 3 mil radial interference is desired. Based on these measurements, 18 mil radial shims were used. Collar OD Yoke ID (Collared coil using Practice coils #1 and #3)

Page 12 Strain gauges on Control spacers show contact made by press to vertical blocks, then contact made to horizontal blocks during skin welding. Stress in skin, from skin gauges, averaged about 250 MPa after welding, about the expected value. Horizontal block Vertical block Horizontal block

Page 13 Near pole Near midplane Near pole Out of range MM#5 Quadrant 1 strain gauge readings

Page 14 MM#5 Quadrant 2 strain gauge readings Near midplane Near pole

Page 15 MM#5 Quadrant 3 strain gauge readings Near pole

Page 16 MM#5 Quadrant 4 strain gauge readings Near pole Out of range Near pole

Page 17 Final midplane shim size of 5 mils (2 ½ mils per side) will be used when collaring TQC01. Collar-yoke shim with 3 mils radial interference (based on measured collar and yoke measurements during assembly) will be used on TQC01. Welding procedure is adequate to achieve proper yoke-control spacer contact. Measured skin stress conforms with analysis. Proceed with TQC01. Conclusions