1. 20 April 2002Bill Lee APS 1 The D0 Silicon Track Trigger Bill Lee Florida State University

2. 20 April 2002Bill Lee APS 2 STT People and Institutions Boston University –Ulrich Heintz, Meenakshi Narain –Evgeny Popkov, Lars Sonnenschein, Jodi Wittlin –Kevin Black, Sarosh Fatakia, Lorenzo Feligioni, Alex Zabi –Eric Hazen, Bill Earle, Shouxiang Wu Columbia University –Hal Evans –Georg Steinbrück –Tulika Bose –An Qi Florida State University –Horst Wahl, Sue Blessing, Stephen Linn, Harrison Prosper –Bill Lee, Sylvia Tentinto-Repond –Reginald Perry, Arvindh Lalam, Shweta Lolage SUNY Stony Brook –John Hobbs –Wendy Taylor –Huishi Dong –Chuck Pancake, Bonnie Smart, Jane Wu

3. 20 April 2002Bill Lee APS 3 D0 Central Detector Upgrade New silicon tracker, new fiber tracker, new preshower, and a new 2T superconducting solenoid.

4. 20 April 2002Bill Lee APS 4 Silicon Microstrip Tracker (SMT) - ~800,000 total readout channels -6 barrels (4 layers) -~390,000 axial channels -~220,000 stereo channels -12 interspersed (F-)disks - 4 external large area (H-)disks for forward tracking (2 < |  | < 3) ~ 2.4 m SMT half cylinder

5. 20 April 2002Bill Lee APS 5 D0 Central Fiber Tracker (CFT) ~12m long clear light-guides to Visible Light Photon Counters (VLPC) under detector 8 layers of axial and stereo fibers (20 < r < 51 cm), 77k channels VLPC

6. 20 April 2002Bill Lee APS 6 D0 Trigger System L1CTT –Provides tracks from axial CFT fibers SMT unused until L3 L2FW:Combined objects (e, , j) L1FW: towers, tracks, correlations L1CAL Global L2 L2CFT L2PS L2Cal L1 CTT L2 Muon L1 Muon L1FPD Detector L1 TriggerL2 Trigger 7 MHz5-10 kHz CAL FPS CPS CFT SMT Muon FPD 1000 Hz

7. 20 April 2002Bill Lee APS 7 Trigger System with STT What if we used the SMT to improve the tracks from the CTT? L2FW:Combined objects (e, , j) L1FW: towers, tracks, correlations L1CAL L2STT Global L2 L2CFT L2PS L2Cal L1 CTT L2 Muon L1 Muon L1FPD Detector L1 TriggerL2 Trigger 7 MHz5-10 kHz CAL FPS CPS CFT SMT Muon FPD 1000 Hz

8. 20 April 2002Bill Lee APS 8 Track Reconstruction at L2 We could get: –Impact parameter –Improved p T resolution –Fake track reduction

9. 20 April 2002Bill Lee APS 9 Conceptual Design L1CTT  tracks in CFT –Define road in SMT Find clusters in SMT hits Select SMT clusters in roads Fit trajectory to L1CTT+SMT hits. Send results to L2 road data SMT data Silicon Trigger Card Silicon Trigger Card Silicon Trigger Card Silicon Trigger Card Silicon Trigger Card Fiber Road Card Silicon Trigger Card Track Fit Card L2CTT

10. 20 April 2002Bill Lee APS 10 Fiber Road Card (FRC) Communicates with trigger framework and broadcasts control info to other cards. Fans out track data to all other cards manage L3 buffers –Controls the readout to L3

11. 20 April 2002Bill Lee APS 11 Silicon Trigger Card Receives raw data from SMT Finds clusters in axial and stereo strips Associates tracks with axial clusters Outputs clusters with tracks Strip reader Cluster finder Hit filter SMT L1CTT Road LUT SCL L3 L3L3 TFC via serial link from FRC via serial link control logic L3L3 channel logic (x8)

12. 20 April 2002Bill Lee APS 12 STC Prototype Road LUT Road LUT Road L UT Road L UT control logic (8x) channel logic (Xilinx Virtex E) 800k gates 1.1 Mbits RAM 560 pin BGA accommodates all 8 channels  need 1/STC control logic (8x) channel logic (Xilinx Virtex E) 800k gates 1.1 Mbits RAM 560 pin BGA accommodates all 8 channels  need 1/STC

13. 20 April 2002Bill Lee APS 13 Track Fit Card (TFC) One per 30 degree sector Inputs tracks from FRC and associated clusters from STC Farms each track out to one of eight DSPs Outputs input track list and expanded track list to L2 TI6202/3 (300 MHz)DSPs

14. 20 April 2002Bill Lee APS 14 Track Fit Card (TFC) require hits in –at least 3 of the 4 SMT layers –in same 30 degree sector –in at most 2 adjacent barrels choose hits –closest to trajectory defined by CFT and origin linearized  2 fit –  ( r) = b/r +  r +  0 –drop worst hit and refit if 4- hit  2 bad

15. 20 April 2002Bill Lee APS 15 Summary STT will provide D0 with the ability at L2: –to reduce the background signal –to improve p T resolution –to cut on an impact parameter Production of boards is underway. Our goal is to be operational in early summer.