# Presentation: 119267

## The DØ Silicon Track Trigger

**Georg Steinbr****ü****ck**
**Columbia University, New York**
**Collaboration Meeting 10/11/2002**

**Introduction**
**Design**
**Status**
**Schedule**

- 11-October-2002

- G. Steinbrück

## Physics Motivation

**Increase inclusive bb production yield six-fold with low enough threshold to see Z********bb signal **
**Control sample for b-jet energy calibration, bb mass resolution, b trigger and tagging efficiencies    **
**Top quark physics**
**Factor of 2 improvement in top mass resolution due to improved jet energy scale calibration **
**Heavy bb resonances for Higgs searches**
**Double trigger efficiency for ZH********(********)(bb) by rejecting QCD gluons and light-quark jets **
**b-quark physics**
**Lower p****T**** threshold on single lepton and dilepton triggers                       (B****O************, B****s**** mixing, etc.)**
**Increase B****d****o********J/********K****S****yield by 50% (CP violation) **

- 11-October-2002

- G. Steinbrück

## STT Overview

**STT Overview**

- CFT H layer

- 1-mm road

- SMT barrels

- CFT A layer

- 11-October-2002

- G. Steinbrück

## Contributing Institutions

**Boston University**
**U. Heintz, M. Narain, E. Popkov (PD), L. Sonnenschein (PD), J. Wittlin (PD), K. Black (GS), S. Fatakia (GS), A. Zabi (GS), Amitabha Das (GS), W. Earle (Eng), E. Hazen (Eng), S. Wu (Eng)**
**Columbia University**
**H. Evans, G. Steinbr****ü****ck (PD), T. Bose (GS), A. Qi (Eng)**
**Florida State University**
**H. Wahl, H. Prosper, S. Linn, T. Adams, B. Lee (PD), S. Tentindo Repond (PD), S. Singupta (GS), J. Lazoflores (GS) **
**SUNY Stony Brook**
**J. Hobbs, W. Taylor (PD), H. Dong (GS), C. Pancake (Eng), B. Smart (Eng), J. Wu (Eng) **
**Manchester University**
**Michiel Sanders (PD)**

- 11-October-2002

- G. Steinbrück

## STT Design

**STT Design**

- Sector 1

- Sector 2

**L2 Global**

**L2 Global**

- 6 Identical Crates with
- 1 Fiber Road Card
- 9 Silicon Trigger Cards
- 2 Track Fit Cards

- Partially filled crates in racks 202-204 in MCH2

- 11-October-2002

- G. Steinbrück

## Motherboard and Communication Links

**Boston University**
**9Ux400 mm VME64x****-compatible **
**3 33-MHz PCI busses**** for on-board communications**
**Data ****communicated between cards via point-to-point links**** (LVDS) (LTB and LRB cards)**
**Control signals sent over backplane using ****dedicated lines**
**VME bus used for Level 3 readout**** and initialization/monitoring**

- 11-October-2002

- G. Steinbrück

## Fiber Road Card (FRC) Design

**Fiber Road Card (FRC) Design**

**Columbia University**
**Receives tracks from L1CTT**
**Communicates with trigger framework via SCL receiver card**
**Transmits tracks and trigger info to other cards**
**Manages L3 buffering and readout via Buffer Controller (BC) daughter cards on each motherboard**

- FRC

- Buffer
- controller

- 11-October-2002

- G. Steinbrück

## Silicon Trigger Card (STC) Design

**Silicon Trigger Card (STC) Design**

**Boston University**
**Performs SMT clustering and cluster-road matching**
**Clusters Neighbouring SMT hits (axial and stereo) **
**Each STC processes 8 HDI inputs simultaneously**
**Axial clusters are matched to ±1mm-wide roads around each CFT track via precomputed LUT**
**Mask bad strips and apply pedestal/gain corrections (via LUTs)**

- 11-October-2002

- G. Steinbrück

## Track Fit Card (TFC) Design

**Track Fit Card (TFC) Design**

**SUNY Stony Brook**
**Performs final SMT cluster filtering and track fitting**
**Receives 2 CFT hits and axial SMT clusters in CFT road**
**Lookup table used to convert hardware to physical coordinates**
**Selects clusters closest to road center and performs linearized track fit using precomputed matrix elements stored in on-board LUT**
**Require only 3 hits out of 4**
**Output to L2CTT via Hotlink cards**

- 11-October-2002

- G. Steinbrück

## Hardware Status

- All Boards at hand

- 11-October-2002

- G. Steinbrück

## Downloading and Monitoring

**Florida State University and Boston University**
**STT Crate Initialization **
**Controlled via Power PC at power-up**
**Downloads lookup tables and DSP code to STT cards**
**Existing test-mode uses Python; ****conversion to C for final system done for STC and TFC, in progress for FRC**
**EPICS STT board support package**
**Downloads via COMICS trigger initialization parameters**
**Gathers information from cards for monitoring purposes**
**First pass exists**
**Needs to be extended **
**Need to implement Interrupt Service Routine to react to monitoring request via SCL********FRC********CPU **

- 11-October-2002

- G. Steinbrück

## L2STTCTTWorker

**Boston University**
**Online package (on alpha/ beta) that receives L2 STT output**
**Formats and orders it appropriately**
**combines the inputs from the 12 tfcs into 1 ordered list of ctt or****  stt+ctt tracks (depending on if there's a stt fit)**
** ****sorts by pt, does a few conversions (phi bins, pt bins, etc)**
**Transmits it to L2 Global for final L2 decision**
**has been successfully tested with both 1 and 2 tfc's in standalone mode**
**has been tested with full card chain for mult. Events**
**Integrated into trigger simulator in p13**

- 11-October-2002

- G. Steinbrück

## STT Trigger Simulator

**Florida State, Stony Brook and Boston University**
**Exact DSP fitting code used in tsim_l2stt**
**Some ongoing development to improve the emulation of the hardware/firmware**
**Has been instrumental in developing the fitting algorithm**
**Produces test vectors for all cards**
**Stand-alone package tsim_l2stt **
**Very recently Integrated into d0trigsim********Can be used by the general (D****Ø****) public for physics studies!**
**Can be used with worker for physics studies.**

- 11-October-2002

- G. Steinbrück

## STT Performance

**STT Performance**

-  = 20 m

- 50 GeV muons
- No beam spot

- 11-October-2002

- G. Steinbrück

## Beamspot Monitoring

**Manchester University **
**Use vertex examine to determine beam spot and vertices online**
**Use gtr_l3 and Offline vertexing: Beam position from dca vs phi**
**Write beam position to text file: ******** **
**Beam Monitor: (to do)**
**connected to Vertex examine, SES for alarms, Lumi system to get info ********lumi db and acnet for feedback of beam spot to MCR**
**MCR could implement automatic beam adjustment **
**Writes beamspot to pickle file (updated every ~5 min)**
**TFC picks up beamspot from pickle file**
**Picked up on start of new run (not yet)**
**If beam moves too much********Alarm, stop run, start new run (new beam spot)**
**Beam spot in beg of store: TBD**
**~10 min to get measurement**
**Or: Special run with all L3 dedicated to tracking**
**thanks to Lorenzo and Suyong (beam_tilt / examine)**

- 11-October-2002

- G. Steinbrück

## Beamspot Monitoring

**x**

**y**

**xz**

**yz**

**Beamspot Monitoring**

- Critical for the STT!

- 11-October-2002

- G. Steinbrück

## Integration Tests

**Used fake data sender (tracks to FRC and hits to STC) to verify transfers between all 3 types of boards**
**Fake data sender triggered by L1 accepts: Have started to test integration of FRC with SCL signals ******
**Next step: tick and turn number in fake CTT data **
**Loaded FRC and STC with test vectors and sent multiple events through FRC->STC->TFC->L2 alpha chain ******
**Ongoing: Rate tests using fake data sender**
**L3 readout involving FRC ******** BC communication in progress **
**Real CTT tracks and Silicon hits will be used as soon as L1CTT tracks available!**

- 11-October-2002

- G. Steinbrück

## 30° Sector test

**Instrumenting a 30****°**** sector:**
**One FRC, 6 STC’s, one TFC**
**Full track reconstruction**
**parasitic operation**
**Output to L3 and private DAQ for L2 **
**Status: All hardware at hand at FNAL**
**Transition from Integration tests to sector test  ongoing**
**Work on L3 readout ongoing**

- 11-October-2002

- G. Steinbrück

## Schedule

**Production**
**Installation 1 week (beg of November) No access needed.**
**Now-November: complete 30****°**** sector**
**parasitic operation**
**full track reconstruction**
**output to L3 and private DAQ for L2**
**Without L1CTT: Need to rely on test vectors/ fake data sender**
**	********Limitations: Less realistic, hard to exercise the whole system (track fits with real SMT hits), timing, data volume, L2 and L3 readout**
**With L1CTT: Easier, Faster**
**Full commissioning of the STT will start after installation is complete and all L1CTT inputs are available**

****

- 11-October-2002

- G. Steinbrück

## Run 2B Silicon Track Trigger

**Run 2B STT can process hit information from 5 of the 6 Run 2B SMT layers **
**Achieved by adding 1 STC 2 Track Fit Cards per crate**

- 11-October-2002

- G. Steinbrück

## Conclusions

**Great progress in board production since Oklahoma**
**All boards for Run 2a at hand!**
**Lots of progress in integrating the various pieces**
**Sector test in progress**
**All of this made possible by a dedicated STT group****  **
**Final System Commissioning coupled to L1CTT schedule. **
**Run 2b upgrades involve additional STC and TFC boards.**

- 11-October-2002

- G. Steinbrück