SCT BARREL PAR - RAL 14 -16 May 2003

Status of Barrel Mechanical Structures

- Cylinder manufacture

- Bracket and small components manufacture

- Dry assembly

- Work on barrels before shipment to RAL

- Open issues

- Transport / Logistics

- Schedule

Eric Perrin

1) Cylinder manufacture (by Astrium)

The four SCT cylinders have been delivered from Astriumbetween Oct 2002 and March 2003. Today B3 is at RAL, B6, B5 and B4 at UNI-GE.

Several problems encountered during manufacture introduced delays.

- Machining

- A few pads were de-bonded during machining

- Understanding the Metrology

B4 bracket mounting hole metrology

B5 bracket mounting hole metrology (Problems with holes precision)

Module to structure interfaceModule are fastened in three points

Tilt angle is : 11° for B3 & B411.25° for B5 & B6

2 main points

3rd mounting point

Brackets and small components production. All together there are > 40000 small - special - components to beproduced, some are the sames for the 4 barrels, some are specificto one type of barrel and even to upper or lower modules.

The brackets shells are time consuming to produce and are on the critical path.

Laminate by Composite DesignMachining by UNI-GE

Brackets for B3- A lot of problems encountered during shell manufacturing. Cyanate-ester provedmore tricky than epoxy to use for this application. The company also had autoclave

problems for a few batches. This was in some cases only discovered late, in factduring machining. Approx 150 B3 brackets (out of ~400) have been rejected.

- The new prepreg received has improved things

Bracket shells situation :

B3: DoneB6: Expected Mid June

B5: To be orderedB4: To be ordered

Quite late, we decided to Parylene coat the shells. This works wellbut require a lot of extra preparationwork.

Bracket machining

All Small components for the four barrels have been ordered and delivered except:

- Dogleg clip, first batch (800-for B3) received, production releasefor the next batches (4000 pieces) to be given by RAL.

- PEI module centering bush, first batch of 200 delivered. Change in toleranceidentified. Production release to be given after mounting trial by Oxford.

- Module clip, still need to be finalized, contact have been made with industry for the identification of an appropriate insulating coating. Tests needed.

- 3rd point Clip, Barrel specific item: done for B3 Drawings just finished for the three other barrels. Quotes in May. ProductionJune July.

Work on cylinders before shipment to RAL« Dirty work »- Counterdrilling of outer facing underneath pads, done for B3- Check/adjust mountability of brackets on pads, done for B3- Evtl re-bonding of a PEEK pad, done on B3.- Surface preparation for bonding FSI system.- Some finishing touches

B3 & B6 at Geneva

Dry assembly- B3 was fastened with interlinks into B6, all screws could be fitted and all dowel pins were mounted by hand (H7 - g6 tolerances).- B6 supported by temporary supports fastened into the bearing mounting points.- Work to be redon with B5 and B4.

« Clean Work »

- Cleaning cylinder - Isopropanol, vacuum cleaner, Q-tips etc…- Electrical continuity tests- Mount brackets - all screws tightened with torque controlled screwdrivers (brackets have el-isolated from cylinder).- Rough geometrical check.- Visual inspection- Pack for shipment

B3 ready forpacking - equippedwith shocklogrecorder

Open issues

Interlinks, B6 supports, junction parts to Pixel detector and TRT rails, penetrations through Thermal Enclosure are still conceptual. A crash programme on these items is needed in the next two months

Interfaces with Pixels: - Pixel Support still conceptual (Pixel Tube passed PRR. Induced loads into SCT for most load cases have been reduced by use of flexures. Loads induced by Pixel services still unknown).

Interface with TRT:- Rails and rail extensions to be finalised.

Transport / Logistics

- Each barrel travel from UNI-GE/CERN to RAL in original wooden box.

- From RAL to Oxford, special inner /outer container systemwill be used.

Air transport to Japan- Only way to have temperature controlled is to use a special Envirotainer.

- The largest Envirotainer his is too small to accept B4 in itsinner container.

- Maybe this Envirotainer can be used if B4 would becontained in a simpler and smaller spl frame. This requires extra handling at RAL, at KEK and at CERN.

More work needed.

Schedule for delivery of barrels to RAL

This is mainly driven by Bracket production and assembly

Bracket shells

B3: DoneB6: Production started, aim to complete Mid June

B5: Still to be ordered, expected Mid JulyB4: To be ordered, expected Mid August

Barrels to RAL

B6: End of JulyB5: End of AugustB4: End of September