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GLAST LAT Tracker Tower 11, 12, 13 Pre-Ship Review. Luca.latronico@pi.infn.it INFN-Pisa. Tower 11, 12, 13 finalization + tower 15 assembly made the clean room VERY crowded this week!. Towers Assembly and test flowchart highlights. July 29 - August 16, 2005 (INFN-Pisa) :
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GLAST LAT Tracker Tower 11, 12, 13 Pre-Ship Review Luca.latronico@pi.infn.it INFN-Pisa
Tower 11, 12, 13 finalization + tower 15 assembly made the clean room VERY crowded this week! Towers Assembly and test flowchart highlights • July 29 - August 16, 2005 (INFN-Pisa) : • assembly of complete tray stack • incomplete cable set • tower 11: non-flight C1,C2 • tower 12: missing C5 • tower 13: missing C2, C5 • Functional and performance tests • Sidewalls, alignment • September 1-14, 2005 (Alenia-Roma) • X-Y-Z vibrations • Thermal-Vacuum cycles • September 16-21, 2005 (INFN-Pisa) : • Missing cables installation and replacements • Solithane, EMI taping • Alignment verification, final CPT • Full EIDP details (soon) at: • http://glast.pi.infn.it
Towers – Delivery configurations Tower PN: LAT-DS-00722 (rev3) Tower SN: 11, 12, 13 Environmental test performed with following configuration variations: Tower 11: C1-001 non-flight installed in place of C1-P-004 C2-008 non-flight installed in place of C2-018 Tower 12: C5 missing Tower 13: C2 missing C5 missing Note: 16 cables over 24 came from Pioneer
Towers configuration and mechanical verifications Configuration: • Kapton tape and foam applied on the flex cables as per LAT-DS-00722 • 4 layers of Poron foam 0.037 THK used on Bottom and Top Tray (–X) side (in place of 5 layers) • Base Plate assembly: • Torque of nuts 5.4 Nm, spec is (5.08 +0.56/-0 Nm) Alignment, Mass, COG: • All towers well aligned and inside stayclear • Masses and CG near estimated values (when used real masses) • Full data available from EIDP and INFN-PISA web site
Towers 11, 12, 13 – Open NCRs • Environmental test in non-flight configuration • INFN/PI-NCRs: 568 (twr11), 575 (twr12), 569(twr13) • environmental test runs were performed with missing or non-flight cables, as agreed by an MRB • the NCR can be closed • Hot/cold power off/on not performed • INFN/PI-NCRs: 578 (twr12), 574 (twr13) • The problem is due to a known and documented issue with resetting MCM (NCR 417) with missing cables • To avoid the many and unknown number of power cycle needed to re-establish a good configuration with as many readable layers as possible, hot/cold switch on and off were not performed • SLAC has requested waiver LAT-XR-07340 on this issue relative to towers 7,9,10,12,13 • the NCR can be closed • Vacuum level out of specification • INFN/PI-NCRs: 581 (twr11), 583 (twr12), 582 (twr13) • The situation is similar to earlier TVAC tests and the proposal is to accept the test as for previous MRBs • the NCR can be closed • INFN/PI-573(twr11): some screws out of torque on sidewall +X • ~20% of the +X sidewall screws found out of torque after Z-axis vibration • All screws were re-torqued to spec, X-Y axis vibrations were performed, all screws torque were checked and no change was found • the NCR can be closed
TVAC – vacuum level out of spec Same behaviour as previous tests – the proposal is to accept the test: • Vacuum slightly higher than spec (~> 10-4 vs 5x10-5 Torr) only during hot soaks • Vacuum level improving with time
Efficiency – bad channels correlation spec Towers Efficiency
Conclusions The clean room is sadly empty and people are looking for things to do (maybe) but 3 excellent towers are on their way to the LAT GRID at SLAC