Strip Stave cores Stephanie Yang ATLAS upgrade Oxford activities, January 2015

Barrel strip tracker geometry 25/07/20142 LayerNo of Staves in 360° Radii to Centre of Stave (Stub) Total Number of Cylinders: 5 Total Number of Staves: 600 (including stub and no spares) – currently 8 different stave flavours Total Number of Modules: – 13 Modules per side of stave = 26 modules per stave – 2 Modules per side of stave for a stub

Current Stave Design Critical Dimensions: Overall Length 1277 Width 115 EOS at Z=0 to Silicon Edge 0.1mm Module to Module Gap 0.46mm Pitch of Modules 98mm 3 R Phi Side Stereo Side Peter Sutcliffe 25/07/2014

R-Phi Bus tape Co-cured to Carbon Skin EOS Closeout Cooling Tube Assy Stereo Bus tape Co-cured to Carbon Skin Allcomp foam Cooling strips Honeycomb core Carbon C Channels Allcomp foam End cooling Z=0 Closeout Stave components

Face sheet co-curing The Kapton tape and the high modules carbon fibre co-cured face sheets – 3 layers (0/90/0) of K13C2U(45gsm)/EX1515 – Cure at 120°C The tooling for this is an Ø10” Al half-section pipe – To compensate for differential thermal expansion of tape and carbon fibre – A 10mm oversized rim around the tape to avoid resin bleed and this rim is kept during stave core assembly. It gets milled away at the end of the sandwich production. 5 Resin bleed Sacrificial rim

Locking points gluing jig Stave core tooling Stave core assembly main vacuum jig – Made of Carbon fibre; – Series dowel holes provide the positional reference for the sub jigs; Main sub jigs are: – Glue masking jig – Foam block alignment jig – C-channel placement jig – Glue bath jig – Locking point gluing jig Vacuum jig (Liverpool) C-channel placement jig Foam blocks and end closeouts alignment jig 6

Foam block alignment jig

C channel placement jig

Step 1: place the face sheet on the main jig ( Reference feature: Using dowels at the two ends of the stave centre line to locate the face sheet to the main jig) Two reference fiducial marks /circles of 8mm diameter at the both ends of the over-size region will be added to the tape(Roy will add this feature in his tape design). These marks are used as a template for transferring reference. After co-curing the tapes, cut the OD 8mm holes on the face sheet reference to the fiducial marks, a round hole at z=0 end and a slotted hole at z=1.3m end. Place the co-cured face sheet onto the assembly jig with the tape side facing down and CF side facing up. Using dowel pins at both ends to locate it. Prototype of cutting such holes on the co-cured face sheet 9

Step 2: central ruler for masking 10

Step 3: Foam blocks and end closeouts alignment jig 11

Step 4: place cooling pipe Glue apply jig for cooling pipe 12

Step 5: C channels placement jig 13

Step 6: Glue bath jig Glue bath depth 0.5mm, with 1mm oversized Marking area for BN loaded glue if different glue for the cooling block area is required. Pin to locate the stave partial assembly 14

Step 7: locking point gluing jig NOTE: During the gluing of the locking points, the 10mm over-size region along the longer edges will be removed first, but at the both ends will remain for positioning the stave on the jig during the gluing and will be removed afterwards. 15

Stave production plan Liverpool / Oxford are to produce all the tooling sets, and – Each institute will produce a prototype stave using the given tooling; Or If tooling is produced at multiple site, then – This must reference to a single source of engineering drawings. Finished product will be sent back to a pre- assigned test centre to check conformity; 16