GLAST Large Area Telescope Gammaray Large Area Space

GLAST Large Area Telescope: Gamma-ray Large Area Space Telescope Status report of the italian collaboration Ronaldo Bellazzini Italian project manager

Talk outline § Intro – the LAT TKR and the italian contribution § Schedule & status § The end of Tracker Construction § Responsibilities in the software § Prospectives and conclusions

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 Overview of the GLAST- LAT detector Precision Si-strip Tracker (TKR) Segmented Anticoincidence Detector (ACD) measure photon direction • ~10 K (18 XY tracking planes) 6” singlesided SSD • 880, 000 channels (total) • 228 mm pitch, digital readout • self-triggering • hit efficiency > 99% with noise occupancy <~10 5 • 1. 5 X 0 total • power <210 W/ch reject background of charged cosmic rays • 89 tiles – 1 cm thick • 2 phototubes per tile • Waveshifting fiber embedded • White Tetratec wrapping • Charged particle efficiency > 0. 9997 • Power < 31 W total g GRID Mechanical backbone LAT: 4 x 4 modular array 3000 kg, 650 W Electronics & Flying Software Data Acquisition System process events from 16 towers, apply trigger selection to reduce L 1 T rate from ~4 KHz to ~30 Hz R. Bellazzini Hodoscopic Cs. I Calorimeter(CAL) e+ e measure the photon energy, image the shower • 1536 Cs. I crystals (8 layers) 2 x 2. 7 x 33 cm 3 • 6. 1 104 channels • 2 PIN diodes per end; 2 gain ranges each • ~ 1500 kg • self-triggering • 8. 5 X 0 total • power (total) < 91 3 W

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 Italian responsibilities for the LAT-TKR construction delivery of the GLAST TKR detector, 16 towers, assembled and tested, by 09/2005 SSD procurement and test (INFN/ASI) Ladder assembly (G&A/Mipot) and test (INFN/ASI) Trays panels production (Plyform) Trays panels structural test (ESPI/static) (INFN-Pisa) Trays panels thermal-vacumm test (INFN/ASI) ASI Trays panels integration with ladders and electronics (G&A) Trays functional test (INFN/ASI) Trays C. R. burn-in test (INFN/ASI) Tower assembly (INFN/ASI) Tower functional test (INFN/ASI) Tower environmental test (Alenia/INFN/ASI) R. Bellazzini 4

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 ~2 weeks slip due to flight cables late delivery – compensated by availability of spare unit R. Bellazzini 5

Flight cables (SLAC) Tower Containers (SLAC) ü ü ü ü B ü ü ü ü 1*1 ü ü ü ü 2 ü ü ü ü 3 ü ü ü ü 4 ü ü ü ü 5 ü ü ü ü 6 ü ü ü ü 7*2 ü ü ü ü 8*2 ü ü ü ü 9 ü ü ü ü 10 ü ü ü ü 11 ü ü ü ü 12 ü ü ü ü 13 ü ü ü ü 14 1 X ü ü ü ü 15 ü ü ü ü Tower assembly & test (INFN) Tower Env. Test (INFN) Tower deliveries GRID Integration * environmental tests repeated (full TVAC, Z-axis VIB) after tray replacement Notes X replacement tray qualified with custom vacuum and thermal test with full readout 1 tray failure details: 1 ladder with HV short due to a hidden bubble inflated by vacuum 2 tray failure details: 1 noisy ladder at high T due to an unknown instability in the FE electronics Hand-off to SLAC-I&T Ship to SLAC-TKR Pre-ship CPT TVAC VIB Pack / ship CPT alignment assembly MCM (SLAC) ü Flight trays A Tray panels Parts procurement and integration (INFN) Si-Ladder Flight Tower TKR Tower production status Tower 16 • Trays in integration • Assembly mid oct. • For calibration

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 The 16 th and last Tracker flight tower is done! INFN-Pisa R. Bellazzini 8/25/2005 7

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 The LAT Tracker numbers 11500 sensors 360 trays 18 towers ~ 1 M channels 83 m 2 Si surface > 240 K functional test recorded in DB ~ 30 M strip tested (30 test/strip on average) > 60 physicist and engineers involved in the italian teams from INFN (Trieste, Udine, Padova, Pisa, Perugia, Roma 2, Bari) in partnership with ASI R. Bellazzini 8

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 Silicon layers detection efficiency 97. 7 % of layers have efficiency >= 99% Tower Layer Eff. (%) Tray A Y 0 96. 1 B 003 -Fr A Y 3 89. 9 H 020 -Bk A Y 4 85. 3 H 020 -Fr A X 1 92 L 013 -Fr A Y 6 97. 9 H 012 -Fr 3 Y 0 96. 1 B 008 -Fr Cause / corrective action Wire bonds between adjacent SSD along ladder interrupted by encapsulant delaminations – encapsulation between SSDs removed on heavy and bottom tray ladders Wire bonds between MCM chips and pitch adapter broken by encapsulant delaminations – new MCM handling, shipping and assembly fixture <= R. Bellazzini • very similar performance for all >11500 SSD • carefully grouped for ladder and tray assembly based on Vdep 9

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 cucina italiana I – tower ingredients 38 C-fiber facesheets 576 SSD Ø 55 K channels Ø 228 m pitch 19 Al honeycomb 38 C-C MCM closeouts 38 C-C structural closeouts 36 Multi-Chip Modules 4 C-fiber sidewalls 8 kapton flex cables 36 kapton bias circuits ~ 1000 screws (several types) 192 3% X 0 W tiles 64 12% X 0 W tiles glue, paint, tape …… R. Bellazzini 10

INFN-Pisa Gruppo II, 5/10/05 straight GLAST LAT Project cucina italiana II – the course: The famous leaning towers …. and the flavour Sidewalls assy Vibe test R. Bellazzini TV test Shipment to SLAC Sidewall removal 11

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 Tower assembly and alignment Many different components are integrated into the tracker: • the excellent intrinsic precision of base components (SSD, 2 m rms wafer cut precision) is fully exploited and maintained in higher level components (e. g. measured ladders displacement (X/Y/Z) on trays has an RMS ~ 20 m) • assembly procedures overcome limitations from specific materials (composites, glue) and deliver integrated units (trays, towers) with monolithic performance • the silicon layer position in the tower can be controlled offline with 3 parameters (Dx/y, DZ, Df) only 1728 constants for the LAT (>55 K for single SSD) CR layer residual after offline corrections rms= 137 m MC layer residual perfect geometry rms= 124 m what remains after the correction is very similar to MC data, where only intrinsic tracking fluctuations hold (single hit resolution and multiple scattering) R. Bellazzini 12

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 Celebrations for the end of Tracker construction R. Bellazzini 13

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 Celebrations for the end of Tracker construction 52 attendees from INFN, ASI, SLAC, NASA, italian industrial partners R. Bellazzini 14

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 Celebrations for the end of Tracker construction recollections of the many efforts that lead the team to such great achievement • > 11500 SSD from HPK tested at INFN in 3. 5 years • 0. 5% rejection rate • ~2900 ladders built by industry (G&A, Mipot) and tested by INFN in ~ 3 years • ~ 1% ladder rejection rate • 370 bare panels assembled by industry (Plyform) ESPI (resonance and defect search) And tested by INFN R. Bellazzini Workmanship TVAC test 15

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 Celebrations for the end of Tracker construction recollections of the many efforts that lead the team to such great achievement Trays burn-in test with C. R. Trays thermal cycle • 360 trays integrated (Si/MCM/mechanics) by industry (G&A) Tray test by INFN >540 equivalent days of operation for space qual • 3 non-flight trays (bad channels >1% any side) due to delaminations in the MCM • good for calibration unit (max bad chans on one side 9%, average 4%) R. Bellazzini 16

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 Celebrations for the end of Tracker construction recollections of the many efforts that lead the team to such great achievement Towers environmental tests by INFN using Alcatel-Alenia facilities Towers assembly and test by INFN • 17 towers in 10 months 12 TVAC Test runs (5 single + 7 pairs) • 4 failures over 612 si-layers 20 VIB Test runs (17 full + 3 Re-Test) • 0 failures R. Bellazzini 17

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 Celebrations for the end of Tracker construction The contributions to GLAST by the entire Italian team are enormous …. The spirit of collaboration established by the tracker team has been an example for the entire collaboration …. Congratulations and thanks to all! P. Michelson, GLAST Principal Investigator Also many aknowledgements from SLAC (P. Drell), NASA (K. Grady) R. Bellazzini 18

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 The GLAST heritage Industrial partners (G&A/Mipot/Plyform/Alcatel-Alenia) â modules prototyping @ INFN â process engineering and mass production by industry for reliability and yield â final acceptance test by INFN proved to be a virtuos loop if INFN directly involved with all subcontractors w/o main contractor filter (as opposed to typical space agencies policy) Project management (INFN/NASA/SLAC) â Control of external supplier production â coordination of the italian activities â reporting to project office INFN-Pisa leading role in Italy GLAST Team @ INFN Quality Assurance Science policy (NASA and the Astrophysics Community) Public data policy â 60 days proprietary to team for calibrations â 1 st year access through approved guest investigators â after completely public Global network of detectors Common policy for space observatories Necessary for multi-l campaigns and transient detections with other detectors R. Bellazzini (NASA/SLAC/ASI and industrial suppliers) âclear protocols for material shipping, receiving and inspection (incoming) â efficient maintenance of documentation and internal consistency through configuration control âquasi-commercial attitude helps defining responsibilities and expected deliveries âwell-defined protocol for management of unexpected deviation from requirements (NCR) Needed for operation in space where no intervention is possible All such requirements flown into custom database 19

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 Integration and test at SLAC 8 TKR towers in the GRID half LAT) 8 towers g candidate events TKR inter-tower alignment (top) 1 st g event R. Bellazzini 20

GLAST LAT Project R. Bellazzini INFN-Pisa Gruppo II, 5/10/05 21

GLAST LAT Project R. Bellazzini INFN-Pisa Gruppo II, 5/10/05 22

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 Construction and test activities for 2005/2006 • 2005 – Support construction and calibration of beam test calibration unit (tracker tower 16 + tracker spare tower + 4 CAL modules) – Provide and calibrate beam test ancillary systems (photontagging station, beam line diagnostics) and integrate them with calibration unit – LAT integration and calibration • 2006 – LAT integration and calibration, Environmental tests – Support integration to spacecraft – Beam test of towers – beam time request for: • 3 weeks at PS for 50 Me. V-~Ge. V e- and g tagged • 3 weeks at SPS for 300 Ge. V e. R. Bellazzini 23

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 Beam test planned setup g-tagging station at PS/T 9 The Agile setup at T 9 § g energy range : ~50 Me. V-~Ge. V § beam is a mixture of e-, p, p, with e- fraction rapidly decreasing with energy (<50% at 3 Ge. V) § e- deflection is measured with 5 mrad resolution momentum resolution is 2. 5% Dp/p + 2% from beam R. Bellazzini 24

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 INFN software activities • • • Simulation and reconstruction SW – MC (G 4 development, maintenance and validation) – TKR digitization algorithms – Event display (FRED) – Source simulation (GRB, PSR, AGN, DM, …) Core SW – MRvcmt – rdb. Gui TKR construction and I&T SW activities – Tower performance studies – Offline studies during integration Science SW – Instrument Response Functions studies – BKG rejection analysis – Source detection, specific GRB & PSR tools (included in Data. Challenge 2 and science tools periodical benchmark test) Science Working groups – Active participation to all groups – INFN coordinators for GRB and Dark Matter groups R. Bellazzini 25

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 The MC Simulation • G 4 as proposed MC • Learning G 4 and development of Gamma. Ray. Tel • Standalone Packages – Test Beam 1999 – Balloon Flight • Geometry repository • Gaudi integration – Managing the event loop – Source generation – Hit generation by G 4 – Digitization – Reconstruction • G 4 adopted as official MC • Continuing validation activity • MC data production phase R. Bellazzini 26

• • GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 The FRED Event Display Flexible Hep. Rep based User friendly GUI Works both locally and remotely Open. GL 3 D based graphics Used both for offline SAS tasks and the I&T Continuous development to include more features and use cases R. Bellazzini 27

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 Track reconstruction for alignments Residual vs. slope of track real position X 3 X 2 X 1 ideal position res = - x + z · cot( ) Aligns: • horizontal ( to strips) • vertical typical displacement: 90 µm typical rotation: 0. 2 mrad R. Bellazzini 28

GLAST LAT Project INFN-Pisa Gruppo II, 5/10/05 Source identification • Development of the PGWave package for quick look analysis of LAT data (source detection & characterization). • Development of a fast scientific GLAST LAT simulator • Study of the LAT PSF. PGWave application to a LAT simulated sky field R. Bellazzini Light. Sim simulation of the Galactic Anti. Center Region 29