Tracker Subsystem1 GLAST LAT Project FM1/3 PSR, April 20, 2005 GLAST LAT Tracker Tower-1/3 Pre-Ship Review INFN-Pisa

Tracker Subsystem2 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 1 - Assembly and test highlights Feb 14-21, 2005 (INFN-Pisa) : –assembly (tray stack, cables, sidewalls, alignment, turn-over) –test (CPT) Feb 28 - Mar 14, 2005 (Alenia-Roma) : –VIB test –TVAC test: noise anomaly on layer X16 (see NCR INFN/PI-430) Mar 17-19, 2005 (INFN-Pisa) : –Replacement of tray 17 (M063) Apr 5-15, 2005 (Alenia-Roma) : –New VIB test –New TVAC test Apr 19, 2005 (Roma) –Through customs in Roma airport Full EIDP details at: – (soon available) –Quality Assurance page –EIDP links

Tracker Subsystem3 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 1 - Assembly and components details Tower PN: LAT-DS (rev3) Tower SN: 1

Tracker Subsystem4 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 1 - Configuration Configuration: Kapton tape applied on the flex cables only on termination resistors Poron foam THK used on bottom tray sides +Y and –Y (1 foam layer on cables) 3 layers of Poron foam THK used on Bottom Tray X sides and Top Tray -X (in place of 5 layers of 0.037) Substitution of tray 063 according procedure in Annex 2 NCR/FM/INFN-PI- 430 See NCR/FM/INFN-PI-430 & NCR/FM/INFN-PI-435 for more details

Tracker Subsystem5 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 1 - Alignment data All measurements within stay-clear and within specification.

Tracker Subsystem6 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 1 - Alignment data Bay to Tower Assembly <50 microns offset Center BCS to TCS ≈0 deg rotational offset from BCS to TCS Sidewalls Profile SCS Same shape and dimension Same stayclear margins Difference worst case <50 microns

Tracker Subsystem7 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 1 - CG & MASS Conclusions Tower 1 well aligned and inside stayclear Test after environmental tests skipped as per MRB 3/24/2005 Mass and CG near estimated values (when used real masses)

Tracker Subsystem8 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 1 – Open NCRs INFN/PI-424: Noise anomaly on layer Y0, ladder 3. –Appeared once at first TVAC cycle and never showed again. the NCR can be closed –As per MRB held on March 21, 2005, the NCR can be closed. INFN/PI-430: Malfunction of layer X16, ladder 0. –Consistently observed in vacuum. –The tray has been replaced and it’s now under investigation. –New VIB and TVAC tests passed successfully. the NCR can be closed –As per MRB the NCR can be closed. INFN/PI-459: Vacuum level out of specification. –Common to Tower 3, see following slides. INFN/PI-461: Communication problem when reading the two towers together. –Common to Tower 3, see following slides.

Tracker Subsystem9 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 1 - disconnected channels ~ 250 disconnected channels overall (less than 0.5%). Number of disconnected channels basically stable throughout the environmental tests. The small variation is almost completely due to three layers (related NCRs at the tray level closed): X17 – some cracks on the pitch adapter, no change at all through TV cycles Y0, Y3 – most likely it’s a delamination issue

Tracker Subsystem10 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 1 - Efficiency Overall efficiency (as measured during the post-TV CPT) at the tower level is 99.6%.

Tracker Subsystem11 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 3 - Assembly and test highlights Mar 15-29, 2005 (INFN-Pisa) : –assembly (tray stack, cables, sidewalls, alignment, turn-over) –test (CPT) Apr 4-15, 2005 (Alenia-Roma) : –VIB test –TVAC test: Apr 19, 2005 (Roma) : –Through customs in Roma airport Full EIDP details at: – (soon available) –Quality Assurance page –EIDP links

Tracker Subsystem12 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 3 - Assembly and components details Tower PN: LAT-DS (rev3) Tower SN: 3

Tracker Subsystem13 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 3 - Configuration Configuration: Kapton tape applied on the flex cables as per Annex to NCR/FM/INFN-PI- 435) Poron foam THK used also for bottom tray sides +Y and –Y ( 3 Kapton tape layers + 1 foam layer) 4 layers of Poron foam THK used on Bottom Tray –X side (in place of 5 layers)

Tracker Subsystem14 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 3 – Open NCRs INFN/PI-439: Disconnected channels on the bottom tray. –38 disconnected channels found after the tray assembly –Increased up to 70 after the thermal cycles at the tray level (delamination issue) –Some further fluctuation during the tower environmental test the NCR can be closed –As per MRB the NCR can be closed. INFN/PI-452 minor: Little scratch on one of the wafers of LGT 014. –Occurred while connecting cable 6 – J2 connector. –The layer has been continuously monitored during the tower environmental tests –The NCR can be closed –The NCR can be closed. INFN/PI-473 minor: Wrong positioning of the shock recorder on the ISC. –The shock recorder is rotated by 180 degrees on the x-y plane with respect to its nominal position. –The proposed disposition is close the NCR and use as is. INFN/PI-459: Vacuum level out of specification. –Common to Tower 1, see following slides. INFN/PI-461: Communication problem when reading the two towers together. –Common to Tower 1, see following slides.

Tracker Subsystem15 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 3 - Alignment data All measurements within stay-clear and in spec

Tracker Subsystem16 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 3 - CG & MASS Conclusions Tower well aligned and inside stayclear Test after environmental test skipped as per MRB 3/24/2005 Mass and CG near estimated values (when used real masses)

Tracker Subsystem17 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 3 – Disconnected channels ~ 200 disconnected channels overall (less than 0.5%). Number of disconnected channels basically stable throughout the environmental tests. The overall variation is basically due to the fluctuations in the bottom tray.

Tracker Subsystem18 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 3 - Efficiency Overall efficiency (as measured during the post-TV CPT) at the tower level is 99.6%. The only layer out of spec is the bottom tray (see NCR INFN/PI-439)

Tracker Subsystem19 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 1 and 3 – Communication problems Relevant NCR: –INFN/PI-461 Symptoms: –Impossible to operate the two towers at the same time – except for the simple register tests –Both towers consistently 100% functional when tested one at a time –All the electrical tests foreseen by the procedure performed for the two towers in series Root cause: –The problem is still under investigation –It is clearly an issue with the EGSE/test setup and NOT an issue with the towers. Proposed disposition: –Continue the investigation, close the NCR INFN/PI-461 (on Tower 1 and 3) and open a different NCR on the EGSE setup.

Tracker Subsystem20 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 1 and 3 – Vacuum level out of spec Relevant NCR: –INFN/PI-458, INFN/PI-459 Non conformance: –The vacuum level at the first hot soak was 1.04E-4 torr (specs call for 5E-5), getting better in the following cycles. Considerations and proposed disposition: –The annex to the two NCRs contains a details analysis of the data collected during the environmental tests (explaining why INFN thinks that the goal of the test has been achieved), as well as suggestions for possible improvements of the test facility. –See –The proposed disposition is use as is.

Tracker Subsystem21 GLAST LAT Project FM1/3 PSR, April 20, 2005 Tower 1 and 3 - Conclusions Assembly and test highlights: –Both towers well aligned and within stayclear –The overall number of disconnected channels is very low –All the silicon layers (but the bottom tray of tower 3) close to 100% efficiency –First environmental test of a tower (tower 1) after the EMI taping successfully completed –A few NCRs needed the completion of the environmental tests to be closed Issues: Tower 1 - layer X16 –Noise anomaly detected during the environmental tests. –The tray has been taken apart and replaced –Environmental tests at the tower level have been repeated. Investigation on the problematic tray goes on in parallel Issues: Communication problems –Clearly due to the test setup, investigation is in progress –All functional tests performed with one tower at a time powered