1. GLAST LAT ProjectGSFC Monthly, 30 March 2006 LAT System Engineering 1 GLAST Large Area Telescope: LAT System Engineering LAT Quality Assurance Pat Hascall Joe Cullinan Gamma-ray Large Area Space Telescope

2. GLAST LAT ProjectGSFC Monthly, 30 March 2006 LAT System Engineering 2 Topics NCR Metrics Significant NCRs NCR List LAT Level Verification Status LAT Power Update

3. GLAST LAT ProjectGSFC Monthly, 30 March 2006 LAT System Engineering 3 SubsystemOpen NCRs Closed NCRs last 30 days NCRs Open 30 days or more NCRs open 90 days or more NCRs ready to close (disposition complete; need final QA/MRB review to close) DAQ20132015 Tracker35333 Mechanical34322 CAL00000 ACD*0*0000 I&T6320371715 * All NCRs related to ACD are now categorized as I&T NCRs (including 5 open ACD PRs and PFRs from GSFC) LAT NCR Metrics 3/28/06

4. GLAST LAT ProjectGSFC Monthly, 30 March 2006 LAT System Engineering 4 Open I&T NCR Metrics 3/28/06 Open I&T NCRs FebruaryMarch 6163 New NCRs created1422 NCRs closed320 NCRs Ready to Close (analysis complete, need final QA/MRB review to close) 2111 NCRs with Analysis in Progress 3646 NCRs to remain open to monitor trend or performance 46

5. GLAST LAT ProjectGSFC Monthly, 30 March 2006 LAT System Engineering 5 NCR 863 Anomaly Description –LCI script TkrNoiseAndGain causes the LAT to enter a state of continuous Busy. Livetime stops incrementing, and all TREQs are discarded. Investigation –Similar tests worked on LAT via LATTE –Preliminary investigation shows that a TEM is Busy, with corresponding TKR and CAL contributing to Busy. Monitoring of VSC FIFO flags shows no evidence that downstream backpressure is contributing to the Busy state –Determined that the data rate is too high coupled with a known timeout setting error (already a FSW JIRA) Resolution –Reduce the rate of data collection –Modify TEM settings during LCI runs to minimize/eliminate susceptibility to overrun

6. GLAST LAT ProjectGSFC Monthly, 30 March 2006 LAT System Engineering 6 NCR 855 Anomaly Description –Intermittent LATC verify errors, indicating that the registers are not set up properly Investigation –All instances have been readout controller (RC) registers –LATC verify report bug fixed to allow visibility into problem –Last 2 events provided some clues which are being investigated offline Resolution –Testing has been moved to the Dalek –LAT is being monitored with a plan to use LATTE to capture LAT state if the problem repeats

7. GLAST LAT ProjectGSFC Monthly, 30 March 2006 LAT System Engineering 7 NCR 684 Anomaly Description –Tracker modules have occasional out-of-spec noise occupancy in isolated layers (“noise flares”). Investigation –Analysis showed similar noise at INFN. –Occupancy still within spec. –Noise flares have been observed from 4 layers (out of 576 layers) during 21 hours of 16-tower muon data monitoring. Two of the layers are in flare states for 10-20% of time while the others are in flare states for 1-2% of time. –TKR meets data occupancy and trigger occupancy requirements even during flares. –No noise flares have been observed in review of 230 hours of online Tracker FM 8 data taking, a more detailed review of offline data is in process. Resolution Plan –Continue extended testing on Tracker module 8 to further characterize.

8. GLAST LAT ProjectGSFC Monthly, 30 March 2006 LAT System Engineering 8 Open I&T NCR List NCR Date Opened Affected HardwareProblem DescriptionStatus 4585/10/05TEM/TPSObserved GTCC and GTRC phasing errors within the TEMFinalMRB required 4775/23/05TEM/TPSTEM FIFO errors observed during FMA and FMBFinal MRB required 5296/16/05TKRTEM register test on PDU1 and GASU redundant failed,Twr 3Monitor 5326/16/05TEM/TPSTEM register test (Trigger Interface Controller) failed.Final MRB required 5356/20/05TKRMonitor trend data for TKR 4 thru LAT testing (spin-off NCR)Monitor 5496/27/05TKRTemperature alarm and setpoints, Bay 1Final MRB required 6048/11/05TKRBay 4 TkrReadingConfigurationTest failure on x0, FE0QA to close 6248/27/05ACDFluctuations in temperature reading (originally an ACD PR)Monitor 6258/27/05ACDAcdVetoHitmapPha failed (originally an ACD PR)Monitor 6268/27/05ACDACDMonitor script high counts during T/V (originally ACD PR)Monitor 6489/13/05ACDI&T ACD Receiving Test - AcdGafeNoise failureDisposition Required 68410/3/05TKRNoise Occupancy failures due to intermittent hot strips.Disposition Required 68510/3/05ACDHldCal runs had excessive counts for GARC11, GAFE13Disposition required 69010/6/05PDUNCR to trend LPT failures observed in box level NCR #00631.Disposition Required 71810/27/05ACD VETO threshold for channel 1123 can't be set below minimum value of 0.45pC (originally an ACD PR)Monitor 74111/11/05IntegrationHIB Cables to short or wrong orientation.QA to Close

9. GLAST LAT ProjectGSFC Monthly, 30 March 2006 LAT System Engineering 9 Open I&T NCR List NCR Date Opened Affected HardwareProblem DescriptionStatus 74311/13/05IntegrationEMI shield mechanical tolerances not met.QA to Close 74411/13/05IntegrationX-LAT plate mechanical hole tolerances not met.Disposition required 76512/5/05IntegrationX-LAT Heat pipe shims bonding fixture cannot be removed.MRB Required 77412/8/05IntegrationCannot mate harness LAT-DS-02092-53.MRB Required 77712/13/05IntegrationDAQ-ACD Internal RF shield to GASU cable rework.MRB Required 78812/21/05GASUGASU AEM temperature alarmMRB Required 78912/21/05TKRTKR test software isn't reading in bad channel listsDisposition Required 79112/22/05ACDACD CPT script turns off/on all TEMs simultaneouslyDisposition Required 79312/28/05ACDGARC digital 3.3V current is slightly below allowed rangeDisposition Required 79512/30/05ACDACD TciRegRange test gives bad linearity fitsDisposition Required 79612/30/05ACD ACD TciHighRange test GARC 0 GAFE 11 Upper Gain slightly below limit.Disposition Required 7991/5/06DAQTKR Analog voltage overshoot during power on sequenceQA to Close 8051/16/06MechanicalMapping problem wit hgrid temperature points 2,3 vs. 4,5Disposition required 8061/17/06TriggerCAL is retriggering during SVAC runDisposition required 8081/17/06IntegrationHarness connector backshell is loose (not properly torqued)QA to Close 8111/23/06Integration1553 cables rejected for workmanshipMRB Required

10. GLAST LAT ProjectGSFC Monthly, 30 March 2006 LAT System Engineering 10 Open I&T NCR List NCR Date Opened Affected HardwareProblem DescriptionStatus 8232/6/2006ACDFREE Board 0 failed to initialize during PowerOn using FSWQA to Close 8242/6/2006IntegrationVSC required reboot by resetting SBCDisposition required 8272/9/2006MechanicalInsufficient screw thread engagementDisposition Required 8292/10/2006ACD ACD coherent noise at 1000 system clock ticks after each event collected in flight config.Disposition Required 8302/10/2006Integration EPU J5, J8 connectors interfere with HIB connectors J5, J6 in Bays 00 and 12Disposition Required 8322/16/2006TKR Calibration DAC correction factor did not work as expected on TkrThresholdCal.pyMRB Required 8332/17/2006DAQ SIU/EPU crates to be removed from LAT for RAD750 EEPROM bonding inspectionMRB Required 8342/23/2006MechanicalAccel mount bracket interferes with EPU screwsDisposition Required 8362/27/2006Mechanical MLI bar bracket does not mount flush, has insufficient thread engagementDisposition Required 8382/28/2006DAQ Spare HCB had moisture condensation occur after T/V chamber was openedDisposition Required 8393/6/06IntegrationUpper cable trays misoriented 90 deg. on +X and -X sidesDisposition Required 8403/8/06DAQ RunControl software problems observed on spare PDU during T/V test (NCR #794); opened NCR to track FSW updatesDisposition required 8413/8/06MechanicalNeed to perform HiPot test on radiator heatersDisposition required 8423/9/06IntegrationVelcro outgassing properties to be verified at GSFCDisposition required

11. GLAST LAT ProjectGSFC Monthly, 30 March 2006 LAT System Engineering 11 Open I&T NCR List NCR Date Opened Affected HardwareProblem DescriptionStatus 8433/9/06DAQDesign change to DAQ-ACD Internal cableDisposition required 8443/16/06FSWSIU included in round-robin scheduling for eventsDisposition required 8453/16/06FSWTEM register set to incorrect values;TCC event timeout was 0Disposition required 8463/16/06FSW When LPA sets EBM destination, other fields in register are also changedDisposition required 8473/16/06FSW Incorrect TEM config register resulted in incorrect bit positions of redundant GEM/EBMDisposition required 8483/16/06FSWLPA returns a success when LATC verify failsDisposition required 8493/16/06FSWLATC output of problem report is unavailableDisposition required 8503/16/06FSWLATC XML parser created files with occasional errorsDisposition required 8513/16/06DAQ One or more EPU resets unexpectedly due to large number of events and interaction with end of run activitiesDisposition required 8523/16/06DAQLCB errors observed during muon runDisposition required 8543/23/06FSWDigi report occasionally shows ACD header parity non-zeroDisposition required 8553/23/06FSWLATC verify occcasionally reports errors in CRC, SPT, ARCDisposition required 8563/23/06FSW LATC verify error at CRC occurs at first LPA run after power upDisposition required 8573/23/06FSWTKR LCI datataken with pedestal strip are corruptDisposition required

12. GLAST LAT ProjectGSFC Monthly, 30 March 2006 LAT System Engineering 12 Open I&T NCR List NCR Date Opened Affected HardwareProblem DescriptionStatus 8583/23/06FSWDatagram overflow in some CAL and TKR LCI scriptsDisposition required 8593/23/06FSW CAL LCI data compression less than expected, results in very large datagramsDisposition required 8603/23/06FSWBias iteration in ACD not working properlyDisposition required 8613/28/06DAQRF shield to SIU cables need serial numbersQA to close 8623/28/06FSWLCI for lehebiascal does not iterate for bias_dacNew 8633/29/06FSW LCI script TkrNoiseAndGain causes TEM to enter a state of continuous BusyNew 8643/28/06FSWPower off runs 77001940 to 77001942 had issuesNew 8653/28/06FSWStrange packets in run 077001868New Not on summary list

13. GLAST LAT ProjectGSFC Monthly, 30 March 2006 LAT System Engineering 13 LAT Level Verification Status Progress this month –Review of ~25% of 456 VPs in progress, all others Final 321 Level 2a/2b VPs and 123 Level 3 VPs 144 more VPs now final, remaining VPs in review by requirement owners –VP review by Requirement/Verification Plan owner ~75% complete All received reqt owner comments have been have been incorporated –VPs continue to iterate based on test case design & owner comments Status –VCRM version 15 released –Updated version of the -00010 in review Reqt issues identified by reqt owner and test case development are being incorporated in this version as they are discovered

14. GLAST LAT ProjectGSFC Monthly, 30 March 2006 LAT System Engineering 14 Mass and Power Status Summary Mass –No Change Power –LAT Power Consumption Estimate has decreased by 12.8 W Primarily due to measured GASU data A margin of 16.9% exists to LAT Power Allocation with 96% of the Estimated Power measured.

15. GLAST LAT ProjectGSFC Monthly, 30 March 2006 LAT System Engineering 15 LAT Power Status ACD Estimate no change. TKR Estimate no change. CAL Estimate no change. T&DF Estimate decrease by 12.9 W due to GASU measured data. LAT Power Consumption Estimate has decreased by 12.9W.