Rodger Bossert/Shlomo Caspi TQ Design Issues Rodger Bossert/Shlomo Caspi June 21, 2006

TQS01 MJR strand Aluminum bronze pole pieces. Both inner and outer coil parts glued in. Mica not used. Key and Bladder structure High end load. TQS01 was tested at LBNL in April 2006, reached 87% of short sample, quenches primarily occurred at the cracks between pole pieces. Last quenches all occurred at same place in same coil (at gap between inner lead end key/island and inner pole piece).

TQS01 Structural Components Iron Yoke Aluminum Shell Load Pad Inner aluminum tube Bladder (removed) Load Key

TQC01 TQC01 will be tested at FNAL in early July. MJR strand Aluminum bronze pole pieces Inner pole pieces glued in, but outer pieces mold released. Mica not used Collar and Yoke structure Full round collars. Low end load TQC01 will be tested at FNAL in early July.

Both TQS01 and TQC01 will be reassembled and retested Both TQS01 and TQC01 will be reassembled and retested. TQS01 rebuild is now taking place. TQS01b Reassembly of TQS01. One coil replaced (the one with limiting quenches) No other design changes from TQS01. TQC01b Rebuild of TQC01. Replace full round collars with collars that include outer pole. No other design changes from TQC01. TQS01c/TQC01c 2nd reassembly of TQ01’s. Changes in end loading? Changes in azimuthal prestress?

The next pair of magnets to be built from new coils will be TQC02 and TQS02. TQC02 coils are scheduled to be wound first, beginning next week. Design features/issues are listed below. TQC02 RRP strand – natural progression from the MJR. Will test new cable. Aluminum bronze pole pieces. – same material as was used on TQC01. It is available and has been proven on previous TQs as well as HFM dipoles. It may be desirable, in the future, to use a material that has a coefficient of thermal expansion closer to that of the coils (like stainless steel), but this will be deferred until future magnets. Inner pole pieces glued in, but outer pieces mold released, as was done on TQC01, to allow for outer collar poles. Any change is dependent on TQC01 results.

TQC02 Inner pole pieces modified so that gap is not coplanar between layers. Redistribute longitudinal gaps uniformly between the 3 gaps. (inner and/or outer) Previous TQ’s were not distributed uniformly on either inner or outer coils. Filler material for gaps is G-10 or G-11 as was done on TQC01. Method of assembly – put in rectangular fillers from bottom as was done on TQS01/TQC01 or from top to completely fill space? If fillers are put in from top, an incision will need to be made in ground wrap to insert filler. Previous design Gap Modified

TQC02 Mica not used on pole pieces or wedges. Collar and Yoke structure Full round collars or collars that include poles – dependent on TQC01b results. Low end load. Same as TQC01 and HFM dipoles. Will also depend on TQC01 results. MQXB TQ/with pole TQ/Round

TQS02 RRP strand Titanium pole pieces in both inner and outer coils. Inner pole pieces modified so that gap is not coplanar between layers. Stress relief notch in bottom of inner pole pieces? Both inner and outer pole pieces glued in. Mica not used. Key and Bladder structure. Pads and fillers are iron. Future design considerations for TQS Change in pad and filler material? Lamination of pads/fillers to decrease differential thermal contraction effect? Modified end loading?

Beyond TQC02 and TQS02 Possibly build a hybrid magnet with collared coil in key and bladder structure?