LAT Test Results. GLAST Large Area Telescope. LAT Pre-Shipment Review. Gamma-ray Large Area Space Telescope. J. Eric Grove NRL

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1 GLAST Large Area Telescope Gamma-ray Large Area Space Telescope LAT Pre-Shipment Review LAT Test Results J. Eric Grove NRL Stanford Linear Accelerator Center LAT Test Results 1

2 Purpose / Contents Demonstrate LAT functionality Verify performance requirements Note: majority of sell-off done during/after environmental test Monitor LAT performance via CPT and calibrations throughout Commissioning and Environmental test CPT Detector subsystems Copper paths, interfaces Calibrations Detector subsystems LAT Test Results 2

3 Data products, analysis, and reports Online analysis Mobile Computing Rack Data converted from CCSDS to LSF to LDF Same data format used in LATTE era (i.e. prior to FSW) Analysis scripts and reports from LATTE Offline analysis SLAC computer farm Two reports produced for all runs, corresponding to data products Digi report (basic detector quantities) Trigger info: Total rate; Rates of trigger types; Arrival times ACD: Occupancy; Threshold info; Hit map CAL: Occupancy TKR: Number of strips and layers hit; Time over threshold Reconstruction report (derived quantities) Number of tracks Reconstructed energies, directions, positions TKR-CAL alignment, track extrapolation to ACD Full GLAST community has access and tools for offline products LAT Test Results 3

4 Test matrix Configurations TT V&V LAT Status/Actions required to declare complete Tier ID Name LAT00x LAT Power On X X X LAT01x LAT Power Off X X X LAT04x Establish Science Operations Config 1 1 X X X LAT22x Science Operations Demo X X X Needs a demo of onboard filter. Updates to analysis are in progress. 2 LAT30x ACD CPT 1 1 X X X Needs abbreviated version of AcdVetoCal (30 min run time, deserves to be done outside of CPT, say in LAT-07x). Trending in process. LAT40x CAL CPT 1 1 X X X Trending in process. LAT50x TKR CPT 1 1 X X X Trending in process. 3 LAT07x LAT Energy Measurement Calibration 2 X X X Calibration data being analyzed. LAT21x LAT Timing Measure & Adjust 1 2 X X X Timing data are being analyzed. 4 LAT03x Electrical Power Subsystem Performance 1 1 X X X Testbed test complete. Ready to run. LAT13x LAT/Spacecraft Interface Test X LAT14x LAT/Spacecraft Interface Test (SIIS) 2 X ECD 4/27 5 LAT02x LAT Reinitialization X X X LAT06x SIU/EPU Hardware Functional 1 1 X X X 6 LAT15x LAT Ambient TCS Test 1 1 X X X ECD 4/27, Jana ready for V&V, Copper path check completed successfully. LAT16x LAT Survival Heater Test 2 2 Procedure (No Script); Grist planning TT LAT52x LAT Light Tight Test 2 Procedure based on existing scripts; Grist planning TT 7 LAT65x LAT False Triggers Analysis only. Merging with 22x in process. LAT66x T&DF Transport Errors 1 X X X LAT70x LAT SVAC Flight Config on Ground 1 2 X X X LAT71x LAT SVAC Muon Calibration 2 X X X LAT8xx SVAC Runs 1 1 X X X Needs report review from SE 8 LAT12x LAT Science Modes 1 2 X Part of FQT; Review Requirements with R. Baun 9 LAT20x LAT Science Performance Diagnostics 2 2 Review Requirements LAT23x LAT GRB Handling X ECD 5/1 10 LAT17x LAT Conducted & Radiated Emissions 2 2 ECD 6/1 LAT18x LAT Conducted & Radiated Susceptibility 2 ECD 6/1 LAT31x ACD LPT 2 2 X X X ECD 5/1 LAT41x CAL LPT 2 2 X X X ECD 5/1 LAT51x TKR LPT 2 2 X X X ECD 5/1 Config Codes: Color Codes: 1 Executed before shipment to NRL Successful Run on LAT 2 Executed before TVAC at NRL Dry Run on LAT TT Table Top Complete V&V Verification and Validation Complete Debug on LAT LAT Script has been run on the LAT Required for LAT Level CPT LAT Test Results 4

5 Script/Test Status Liens against LAT CPT Detector CPTs Data collected and analyzed; trending is in process LAT Test Results 5 No known script issues in CAL, TKR CPTs ACD CPT AcdTciRegRange (front end gain and linearity test) shows systematically lower gain (~5-10% lower) than GSFC test. Likely cause: change in ACD timing config. Full AcdVetoCal (30 min runtime) is in use; should abbreviate it. LAT-22x (Science Ops Demo) Needs to exercise onboard event filter Needs additional analysis steps (data and trigger aliveness). Coding is in process. LAT-23x (GRB Handling) Test is being coded LAT-14x (SIIS test) SIIS brought up and checked out. Test case is being coded

6 Test status Data integrity issues 1. Dropped word on 256-byte boundary within packet Rare loss of data word, likely caused by dropped read from the SDI board in the VSC. Fixed? To be verified Firmware upgrade and change in a configuration parameter in the SBC made on Mon 24 Apr. 2. Dropped word at end of packet Last word is dropped when length of packet is some particular modulo value. Affects many LPA, LCI runs. Cause is VHDL bug in EBM output chip. Workaround in FSW B0-6-8: add one cell of padding if packet has this particular length Need B0-6-8 installed and operating on LAT before final CPTs 3. Compression error in LCI Occasional error in generation of compression key Rare but repeatable (e.g. affects 1 of 64 configs within a single CAL script) Still under investigation LAT Test Results 6

7 T&DF performance T&DF functionality Trigger system demonstration in CPT Trigger primitive aliveness Scheduler, Engine, and Messaging functionality Trigger and veto efficiency Collected with LATTE, analysis on-going Collected with FSW, analysis on-going Detector subsystems timed-in (calibration) TREQ aligned ACD veto and TKR time-aligned with CAL-LO TACK delay optimized ACD and CAL MIP peaks maximized TKR hit occupancy maximized LAT Test Results 7

8 Trigger summary LAT Test Results 8

9 ACD performance Subsystem performance Minimum-ionizing particle (MIP) peaks Veto rates Veto thresholds Electronics Pedestal centroids and widths Width is measure of noise Gain MIP spectra (PHA) Calibration quantities MIP peaks Veto thresholds LAT Test Results 9

10 ACD trending Pedestal trend Centroid and width difference Two epochs Apr 06 CPT GSFC preship Typical Veto threshold ~ 100 bins Pedestal changes are small Veto occupancy Aliveness test for all Veto signals GEM Veto List Muons during LAT CPT show all channels are alive LAT Test Results 10

11 CAL performance Subsystem performance Gain ( MeV/bin ) Linearity Electronic performance Pedestal centroids and widths Width is measure of noise Gains Front-end linearity Threshold DAC gains Hit occupancy Calibration quantities Gain Linearity LAT Test Results 11

12 CAL trending Time evolution of pedestal width Typical FWHM ~ 4 bins (HEX8) Plot shows stability of 32 channels Front-end linearity Typical avg non-linearity ~ 0.2% Stable to ~0.02% or better LAT Test Results 12

13 TKR performance Subsystem performance Dead strip list Noisy strip list Electronics Noise occupancy Calibration quantities Dead strip list Noisy strip list TOT gain Hit occupancy LAT Test Results 13

14 TKR trending Ba d Cha nne l Tre nd ha nd-off 2TWR 4TWR 6TWR 8TWR 16TWR LICOS Te st phase TkrFMA TkrFMB TkrFM1 TkrFM2 TkrFM3 TkrFM5 TkrFM4 TkrFM6 TkrFM7 TkrFM9 TkrFM10 TkrFM11 TkrFM12 TkrFM13 TkrFM14 TkrFM15 Disconnected channel trend Increase in disconnects < 1.5% since delivery of TKR towers. LAT Test Results 14

15 Calibration Calibration Datasets collected with cosmic muons and test charge injection Both under LATTE and FSW Collections with FSW are on-going Test cases LAT-07x, LAT-70x, and LAT-71x No known problems with scripts Analysis Combination of online (near real time) and offline processing Online processing of FSW data is complete Offline processing in progress Output is set of calibration constants for each detector subsystem Trending system for constants is under development Constants need review by subsystems LAT Test Results 15

16 Sample events Gamma ray converting in TKR Cosmic muon traversing multiple towers LAT Test Results 16

17 Summary LAT assembled and operating under FSW LAT CPT in place Except: GRB Handling Liens: Minor mods to speed acquisition or add analyses Calibrations Data collected with LATTE are analyzed and in use Data collected with FSW are under analysis Calibration constants maintained in SAS/ISOC database Performance trending Trending processes exist, and subsystems are involved Large data volume to consume Status Detectors are operating daily with flight settings Test results with FSW show (approximately) same instrument that we assembled and tested with LATTE Leave SLAC with a baseline reference for entry into environmental test program LAT Test Results 17