1. GLAST LAT Silicon Tracker Marcus ZieglerAPS April Meeting 2004 1 The GLAST Silicon Tracker Marcus Ziegler Santa Cruz Institute for Particle Physics University of California at Santa Cruz GLAST LAT Collaboration ziegler@scipp.ucsc.edu Gamma-ray Large Area Space Telescope

2. GLAST LAT Silicon Tracker Marcus ZieglerAPS April Meeting 2004 2 GLAST LAT Overview e+e+ e–e–  Si Tracker 8.8  10 5 channels 155 Watts 3000 kg, 650 W (allocation) 1.8 m  1.8 m  1.0 m Effective area ~1 m 2 CsI Calorimeter 8.4 radiation lengths 8 × 12 bars ACD Veto Counters Segmented scintillator tiles

3. GLAST LAT Silicon Tracker Marcus ZieglerAPS April Meeting 2004 3 Tracker Construction- Overview Kapton readout cables. 18 19 “trays” stack to form one of 16 Tracker modules. 342 Electronics mount on the tray edges. “Tray” 648 Chip-on-board readout electronics modules. Composite panels, with tungsten foils bonded to the botom face. 342 Tested SSDs procured from Hamamatsu Photonics 4 SSDs bonded in series. 2592 10,368

4. GLAST LAT Silicon Tracker Marcus ZieglerAPS April Meeting 2004 4 Silicon Strip Detector  ~80 m 2 of PIN diodes, with P implants segmented into narrow strips.  Reliable, well-developed technology from particle- physics applications.  Leakage current < 2.5 nA/cm 2  Bad channels < 1/10,000  Full depletion < 100 V. 8.95 cm square Hamamatsu-Photonics SSD before cutting from the 6-inch wafer. The thickness is 400 microns, and the strip pitch is 228 microns.

5. GLAST LAT Silicon Tracker Marcus ZieglerAPS April Meeting 2004 5 Silicon detector GTFE GTRC Binary readout Redundancy scheme Zero suppression Readout Electronics on the Tray

6. GLAST LAT Silicon Tracker Marcus ZieglerAPS April Meeting 2004 6 Readout Electronics Based on 2 ASICs developed exclusively for this project:  64-channel amplifier-discriminator chip (GTFE); 24 per module.  Readout controller chip (GTRC); 2 per module.

7. GLAST LAT Silicon Tracker Marcus ZieglerAPS April Meeting 2004 7 Pulse shape and calibration

8. GLAST LAT Silicon Tracker Marcus ZieglerAPS April Meeting 2004 8 Minitower for taking cosmics data Thanks to Hiro Tajima and Eduardo do Couto e Silva

9. GLAST LAT Silicon Tracker Marcus ZieglerAPS April Meeting 2004 9 Hitmap with Cosmics for three Trays

10. GLAST LAT Silicon Tracker Marcus ZieglerAPS April Meeting 2004 10 Efficiency for cosmic rays