# Presentation: 180575

## The D0 Silicon Track Trigger

- Bill Lee
- Florida State University

- Bill Lee

- 20 April 2002

## 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

- Bill Lee

- 20 April 2002

## D0 Central Detector Upgrade

- New silicon tracker, new fiber tracker, new preshower, and a new 2T superconducting solenoid.

- Bill Lee

- 20 April 2002

## 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**

- Bill Lee

- 20 April 2002

## 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

- Bill Lee

- 20 April 2002

## D0 Trigger System

- L1CTT
- Provides tracks from axial CFT fibers
- SMT unused until L3

- L2FW:Combined
- objects  (e, , j)

- L1FW: towers, tracks, correlations

- Global
-    L2

- L2CFT

- L2PS

- L2Cal

- L1
- CTT

- L2
- Muon

- L1
- Muon

- L1FPD

**Detector**

**L1 Trigger**

**L2 Trigger**

**7 MHz**

**5-10 kHz**

- CAL

- FPS
- CPS

- CFT

- SMT

- Muon

- FPD

**1000 Hz**

- Bill Lee

- 20 April 2002

## 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

- L2STT

- Global
-    L2

- L2CFT

- L2PS

- L2Cal

- L1
- CTT

- L2
- Muon

- L1
- Muon

- L1FPD

**Detector**

**L1 Trigger**

**L2 Trigger**

**7 MHz**

**5-10 kHz**

- CAL

- FPS
- CPS

- CFT

- SMT

- Muon

- FPD

**1000 Hz**

- Bill Lee

- 20 April 2002

## Track Reconstruction at L2

- We could get:
- Impact parameter
- Improved pT resolution
- Fake track reduction

- Bill Lee

- 20 April 2002

## 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

- Bill Lee

- 20 April 2002

## 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

- Bill Lee

- 20 April 2002

## Silicon Trigger Card

- Receives raw data from SMT
- Finds clusters in axial and stereo strips
- Associates tracks with axial clusters
- Outputs clusters with tracks

- Bill Lee

- 20 April 2002

## STC Prototype 

- Road
- LUT

- 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

- Bill Lee

- 20 April 2002

## 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

- Bill Lee

- 20 April 2002

## 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

- Bill Lee

- 20 April 2002

## Summary

- STT will provide D0 with the ability at L2:
- to reduce the background signal
- to improve pT resolution
- to cut on an impact parameter
- Production of boards is underway.
- Our goal is to be operational in early summer.

- Bill Lee

- 20 April 2002