Tracker Group: Safety Issues and Assembly Updates

1. AMS Tracker Meeting 31/01/06 Eric Perrin (GE) on behalf of the Tracker group Tracker mechanics at Uni -Ge Safety issues Assembly Still to be made

2. Bolt analysis Has been done for the 6 Tracker structural joints. - ISAtec extracted maximum loads on bolts from the Tracker FEA model - For the different load cases, as specified in the structural verification plan. - Arndt Schultz von Dratzig (Aachen) gave useful recommandations. - Antonio Alvino (SERMS, Terni) performed the bolt analysis itself on Mathcad. - For 5 joints, slight improvements were needed. A change for stronger bolts or nuts solved the problem. These joints declared Fail-safe by engineering judgement. - In the case of the Tracker feet to Tracker shell joints, further calculations of the loads on each bolt was needed and analysis re-made. The « outer bolt » still exhibits a negative margin of safety on joint separaration. Seems acceptable. 2 cases of Fail safe analysis done: a) 7/8 tracker feet b) highest loaded bolt removed. - All documents at: www.dpnc.unige.ch/users/perrin A memo has been submitted to Jacobs Sverdrup. Approval needed to : - Start Tracker assembly - Procure new fasteners - Finalize Tracker feet

3. The bolts chosen for joint 2 require small changes to be done to the Tracker feet. Change to be implemented before fabrication

4. Tracker fastener list and back off prevention method List delivered to Jacobs Sverdrup Has been updated for structural fasteners (Appendix to Memo) Back-off prevention method defined - Two cases: i) Contained small fasteners : Vibratite accepted ii) Other : Vibratite not accepted ==> Mylar patch or self locking insert Several small modifications in existing parts were or are still needed. Fracture of composites Memo delivered to Jacobs Sverdrup. Item closed Material list Delivered to Jacobs Sverdrup - Still some issues: - Some al. alloy plates to be surface treated in-situ. Alodine 1132 pen received. Coating still to be done. - Stress report demanded for a few components prone to stress corrosion. (ladder feet, inserts ) Work in progress (EP)

5. Isatec also verified that the stronger bolts with higher preload used for joint 2 were nor creating problems for the composite parts themselves 30.1.2006 Sehr geehrter Herr Perrin, die rechnerische Abschätzung der Composite-Belastung für die Verbindung zwischen Tracker Shell und Conical Flange, Joint 2, ergibt für die Komponente Support Flange einen Margin of Safety von 0.39 und für die Komponente Tracker Shell einen Margin of Safety von 1.23. Beide Werte berücksichtigen einen Sicherheitsfaktor von 2. Der Nachweis der Composite-Festigkeit ist damit erbracht. Dabei ist der ungünstige Fall betrachtet worden, dass nur die 0/90-Grad Lagen tragen. Die ± 45-Grad Lagen wurden im Sinne einer zusätzlichen Sicherheit vernachlässigt. Die zu Grunde gelegte Kraft beträgt 5315 N. Sie resultiert aus LC 2 und wirkt auf eine äußere Schraube. Zusammen mit einem Sicherheitsfaktor 2 ist dieser Fall schlimmer, als der max. Fail Safe Fall, FS LC 2 mit 9363 N , da hier nur ein Sicherheitsfaktor von 1 angewendet wird. Die zulässigen Werte sind dem derzeit gültigen ESA Insert Design Handbook (ESA PSS-03-1202 Issue 1, June 1987, Fig. 1.2.7 für eine HM-Faser unter Kompression) entnommen worden. Die verwendeten Werte korrespondieren gut mit Contraves-Daten für HM UD-Laminate unter Drucklast. Für Rückfragen stehen wir gerne zur Verfügung! Mit freundlichen Grüßen ISATEC GmbH i.A. Frank Miehlich

6. We suggested to Bruce Sommer or one of his colleague to present the safety related items in the TIM Tracker session. See answer (27.1.06) below: Eric I’ve spoken with Leland and Paul regarding your request that we present a short presentation during the tracker presentations. It is our opinion that there is really not any significant safety or structural issues regarding the Tracker that would warrant a formal presentation. Quite frankly the Tracker is in great shape. The bolt issues have all been resolved, you’ve provided us with the necessary certificates of compliance for the composites and honeycomb components of the tracker and we have the necessary information to go forward to the Safety Panel for the Phase II Safety review. At the most we could have Paul stand up and mention that to everyone if thats what youre looking for Let us know, Regards Bruce

7. Tracker assembly at Uni-GE The Tracker Assembly Frame (TAF) « Frankenstein machine » has been moved into the « Veranda » Modifications started: - Remove / reposition telescopic supports for inner planes. - Build adapters for conical flanges

8. Assembly of the inner tracker at UniGe • Proposed set-up for storage & insertion into the magnet. • The various lengths of the cables were calculated. Cables are in UniGe • Cables must be installed before the supporting shells. • Extra length must be attached to temporary supports. Divic Rapin

9. Dry assembly of parts partly done

10. Assembly Inner Tracker assembly can start as soon as : - The three inner planes are complete and released for assembly  Done ---- Request for exhibiting two planes at CERN end of Feb ?? - Bolt analysis has been closed. - Assembly equipment is ready. To minimize the risks, and the time the Tracker has to stay in the Veranda, we have decided to delay slightly the start of this assembly: - To finish assy equipment. - To verify that the Tracker cable fixations inside the Tracker volume is adequate. ==> Some further vibration tests needed. - Star Tracker lower supports will be available early March to be bonded to the top conical flange. We plan to do this operation in situ.

11. Assembly procedure for inner Tracker This procedure is clear, except for some details still needing tuning, specially in view of risk minimizing. These points will be discussed and decided in a GE-Tracker Meeting in the next 2-3 weeks. - Mount the top conical flange into the TAF. - Transfer the 3 inner planes into the TAF in order P2, P3 and P4. - Add ladder protection. - Mount the bottom conical flanges into the TAF. - Adjust the position of the planes and connect thermal connectors. - Mount top and bottom cable support structure. - Mount and connect cables on ladders of three external rows +Y and -Y. - Test cable - ladder connections - Mount the two 100° shell sectors - Mount and connect all other cables - Test cable - ladder connections - Mount the two 80° shell sectors - Arrange cables on cable support structure. - Inner Tracker ready to be tranported to CERN Inner Tracker assembly ==> Duration ~2.5 months CERN clean room ready ==> end of 2006 Subdetectors expected at CERN ==> April 2007

12. In parallele, the two outer planes will be equipped with ladders P5 completed with ladders  ~Mid March 2006 P1 completed with ladders  ~End of April 2006 (Tests are not accounted for )

13. Still a lot of things to finalize / fabricate - Tracker feet --- Modifications for joint 2 bolts, --- Production drawings --- Specification, organise quotation --- Place order and follow fabrication - Procure fasteners which need to be replaced - Light tightness at exit of conical flange and around the Tracker feet - Cable clamping ----- Structure to support cables outside the Tracker ----- Paddle on Vacuum case (Design A. Alvino) ----- Clamp at Vacuum case edge (Design A. Alvino) ----- Balcony in front of Tracker crates - Container for Inner Tracker. - Dry assembly of evaporators - Etc...

14. Further assembly steps / parts needed - Redo some bracketry for new evaporators in two parts ? ==> Details to be discussed and agreed with Bart soon - Mount outer evaporator rings to P1 and P5 - Modify (if possible) outer plane containers to be compatible with evaporators For integration - Integration procedure - Inner Tracker handling gear - Installation jig for Inner evaporator (design A. Alvino) - Cable « paddle » and clamps on Vacuum case (design A. Alvino) - Cable balcony for Tracker crates. Miscellaneous: - Prototype condenser (made) - Parts for heat exchanger