SVT INFN LNF - 28 Marzo 2007Alberto Annovi1 STARS: Supercomputers for Trigger Analysis and Real-time...

INFN LNF - 28 Marzo 2007 Alberto Annovi 1

SVT

STARS: Supercomputers for Trigger Analysis and Real-time

Selections

Alberto AnnoviIstituto Nazionale di Fisica Nucleare

Laboratori Nazionali di Frascati

Proposal for Ideas - FP VII


SVTOutline

• STARS

• Trigger: we always need more power!

• CDF trigger problems/upgrades/solutions

• More for the next future?

• SVT & AM could survive after CDF at both

level 1 (CMS @SLHC? SLIM5) and level 2 (ATLAS?)

other applications?


SVTSTARS

STARS: Supercomputers for Trigger Analysis and Real-time SelectionsCurrent and future (HEP) experiments look for

extremely rare processes hidden by severe background conditions.

The trigger dramatically affects our ability to extract these tiny signals from the huge backgrounds.

export the successful parallel CDF trigger approaches to new experiments Challenging: competition with Farm approach

New experiments need powerful exclusive, high resolution triggers! The trigger cannot be “inclusive, low resolution” any more! very large comupting power needed time is critical


SVTLooking for very rare phenomena

Hans Bethe: “Young man, if the cross section is so low, increase the luminosity !”

@hadronic collider not only the luminosity has to be increased, but also the bandwidth, the purity … From collision point all the way to PRL editors Trigger is a critical part of this process: errors cause not-recoverable losses!


SVTCDFTrigger power: (1) TTT: the displaced

TrkTriggerbut also Terrific Tracking (@ L1/L2 )

• Run I collected O(1) Bs--> Ds(all Ds modes)• Run II collected ~2000 Bs--> Ds(Ds--> -->K+K-])• Compare with only 10x integrated luminosity!• The trigger had a much bigger impact than Tevatron

upgrade!!!Without SVT

With SVT

RUN I

RUN II

The SVT advantage:3 orders of magnitude

B0 had + had Trigger

Ks D0

S. Donati, M. Morello, G. Punzi, D. Tonelli, G.

Volpi

Mhh (GeV)

L3 plot 2001SVT TDR 1995


SVTSVT: many different boards 2 years for upgrade PULSAR

x12 wedges

Hit Finder

AM Sequencer AM Board

Detector Data

Hits

SuperStrip

Matching

PatternsRoads

L2 CPU

AM++

Hit Buffer

Tracks + Corresponding

Hits

Roads + Correspondin

g Hits

Track Fitter

AMSRW

HB++TF++Powerful flexible

PULSARSJust add Firmware GF++

P. Catastini et al.


SVT

On the opposite side: FPGA for the same AMchip

P. Giannetti et al. “A Programmable Associative Memory for Track Finding”, Nucl. Intsr. and

Meth., vol. A413/2-3, pp.367-373, (1998).

AM chips from 1992 to 2005• (90’s) Full custom VLSI chip - 0.7m (INFN-Pisa)

• 128 patterns, 6x12bit words each

• 32k roads / wedgeF. Morsani et al., “The AMchip: a Full-custom MOS VLSI

Associative memory for Pattern Recognition”, IEEE Trans. on Nucl. Sci., vol. 39, pp. 795-797, (1992).

In the middle: Standard Cell 0.18 m(INFN Ferrara, Pisa) 5000 pattern/chip AMchip

L. Sartori, A. Annovi et al., “A VLSI Processor for Fast Track Finding Based on Content Addressable Memories”, IEEE Transactions on Nuclear Science, Volume 53, Issue 4, Part 2, Aug. 2006 Page(s):2428 - 2433

NEXT:NEW

VERSIONFor both L1 & L2


SVT

Muon acceptance

Inclusive =31%

Exclusive =63%

Electron acceptance

Exclusive =64%

Inclusive =36%Release lepton quality cuts --> gain acceptance x2Control rate with jet/MET requirements --> exclusive triggersNeed high-quality jet/MET trigger --> under upgrade!

CDFTrigger power: (2) also Terrific Calorimeter selection (@L2 )

WH--> lvbb

triggers


SVTExample: New exclusive

WH-> evbb triggerM. Casarsa et al. (in progress)

A real >80% efficient triggerwith low rate @ peak lumi Using L2 clustering upgrade

Tools

L1_ETTOW>10 GeV

L1_MET >15 GeV

L2_MET > 20 GeV

L2_Ete > 8 GeV

L2_2Jet> 12 GeV


SVTCDF LVL2 Calo upgradeNeed a cone algorithm!

MET>15 GeV

Better Resolution &EfficiencyTurn onfor MET 20 32 L3MET

Better jetResolution

15<ET<18

L2cone

Pacman

Same PulsarsSame

mezzanines


SVTCPU & STARS

LHC HLT strategy: we “JUST” buy CPUs and write software…CPUs are flexible but missing time can freeze the flexibility!

SVT approach: (1st STARS prototype born for a tough JOB)split the algorithmamong different technologiesVLSIs (AM chip), FPGAs (Pulsars+mezzanines), CPUsUse the appropriate tooli.e. no time waste!

Proton-antiprotoncollision point

B decay vertex

Impact parameter (d)

Transverse view

~ 1 mm

We will also buy STARS blocks(Pulsars & AM chips) & write firmware + software


SVT

SVT

Fast Track (FTK) Gr V for L2 @ LHC

SLIM5 Gr V for L1

Next challenge is silicon tracking at both Level 1 & Level 2

LHC

What next ?

Ideas fromP. GiannettiM. Dell’Orso

L. Ristori G. PunziA. Annovi


SVT

CMS: 30 minimum bias events + H->ZZ->4

Tracks with Pt>2 GeV

Help!

30 minimum bias events + H->ZZ->4

Tracks with Pt>2 (or Pt>1) GeV for b/-tagging @ level 2; Pt>5 GeV for leptons @ level 1

Where is the Higgs?

FTK

A powerfultool

Where is the Higgs?

Online tracking: a tough problem


SVTWhere could we insert FTK?

PIPELINE

LVL1LVL1

CALO MUON TRACKERCALO MUON TRACKER

BufferMemory

ROD

BufferMemory

FEFE

Raw dataROBs

2nd output

1st output

Fast Track + few(Road Finder) CPUs Fast Track + few(Road Finder) CPUs

Track dataROB

Track dataROB

high-qualitytracks:Pt>1 GeV

Ev/sec = 50~100 kHz

Very low impact on DAQ

No changeto LVL2

Fast network connectionFast network connection

CPU FARM (LVL2 Algorithms)CPU FARM (LVL2 Algorithms)


SVTB-tagging @ ATLAS (w/o & w/ FTK)

LVL2

EF offline

ATLAS T&P march 2007

LVL2 vs offline10 times less rejection

EF vs offline difference being investigated

with Fast-TracK offlineb-tag performances @LVL2

With FTK use offline-qualitytracks for all triggers, e.g.

sophisticated triggers


SVTFTKsim versus iPatRec - Resolution

Curvature Impact Parameter

Cot()

1/GeV cm rad

M. Dell’Orso, F. Crescioli, G. Punzi, G. Volpi, P. Giannetti et al. (Pisa-Chicago)

On going Real Time Tracking & b//Bs tagging performance study


SVT

Trigger xsec (nb)

(MSSM Higgs)

Selected triggers with tracks/jets

•Di Muon trigger (J/Psi, Bs-> )•L1 two muons Pt>1.5•L2 Pt>2 && Dynamical Prescale

• will use SVT in the future•Z -> bb trigger (bjet calibration, top mass)

•L1 jet5, trk5.5, trk2.5•L2 two trk ip>160 m, ~ same z vertex

two jet5

Rate Bs-> with SVT

•Hadronic di tau•L1 2jet5, 2trk6•L2 2jet10, 2trk10

High Pt electron (W, Z, W+H, top)

•L1 EM8, trk8•L2 EM16, trk8

Luminosity (xE30 cm-2s-1)


SVT

Note limited rejection power (slope) without tracker informationCMS-DAQ TDR

F. Palla Proposal (LECC06 workshop)

26 cm

34 cm

42 cm

50 cm

SLHC:• 100-400 Minimum Bias events/bx (12.5 ns - 50ns)• occupancy degrades performance of trigger algorithms

• Implies raising ET thresholds or use tracks• ~2000 tracks/bx in ||<1.5

•But only a few ‰ have pT>5 GeV/c

•This plan match with AMchip features!!!

4 pixel layer

CMS Muon Rate at L =1034 cm-2 s-1

Current CMS pixels have links for L1


SVT

AMchip receives up to 6 parallel busesfor 6 layers at frequency:AMchip now: 50 MHz (Level 2)Next generation: 100 MHz or more Goal: use SAME CHIP for Level 2 & 1

1 AM for each enough-small space-time Patterns

Hits: position+time stampAll patterns inside a single chipN chips for N overlapping eventsidentified by the time stamp

Main problem: AM input Bandwidth,even if powerful: >10 Gbits/sec divide the detector in thin sectors. Each AM searches in a small

Same blocks --> different applications

x80 wedges

Similar use (L1 tracking) for

CMS (F.Palla proposal)

SLIM5 SuperB? (F. Forti, M. Giorgi et al.)


SVTThe trigger harmonizes the experiment

exclusive selections

The power of a detector can cover the weakness of another

1. Weak coverage?

use only tracking & calorimeter to release muon identification

CDF: topmuons

2. Trigger power: no need for trigger dedicated detectors.The trigger MUST not constrain the detector design!

An alternative CMS L1 track triggerDouble layersmore materialto simplify thethe trigger.Is this a good idea?


SVT

AM Board?

Detector Data

towers

Matching

Patterns

Recover Full resolution

data

L1?L2 CPU

Full resolution jet/electrons ?

AM++?

Hit Buffer

Same blocks --> different applications

SVT for Calo?MEG proven SVT Track Fitter algorithm could do offline gamma reconstruction with 800 phototubes.

Can we use “STARS” for offline-quality calorimeter reconstruction?Same structureSimilar HardwareTo be studied…@ LVL1 ?!?

GigaFitter


SVTSame blocks --> different applications

AM: massive parallelism in data correlation searchescoincidence/anticoincidence of up to 12 measurements!

For example: Muon: T1&T2&T3&not(Ecal)&not(Hcal)&M1&M2&M3&M4&M5

LHCB CDF


SVT

Creare un gruppo di esperti (ampio campo di conoscenze per algoritmi, trigger, fisica, diverse tecnologie e loro interconnessioni: FPGA, standard cell, CPUs, links) che possa in parte realizzare (CDF-FTK) in parte favorire la crescita delle idee esposte con:

1. massa critica sufficiente2. finestra temporale sufficientemente ampia

Cosa vogliamo fare con i fondi Ideas??


SVT

1. Complete CDF: Hardware/Trigger studies/Analysis

2. FTK @ ATLAS (ongoing upgrade proposal Pisa/Chicago +….): Physics case/Hardware/Analysis (to be approved)

3. New AM chip for level1 – level2

Favor other project development for upgrades & other

CMS – SuperB ….. sharing:

1. Hardware (in particular new AM chip)

2. software tools (simulation/diagnostic-control-config.)

3. Trigger ideas

STARS could generate new Ideas projects:

Brain study – Routers – security(Cooperation)

STARS

CMS?

SuperBL1?

Brain Study

Routers-Security?

LHCB?

Cosa vogliamo fare con i fondi Ideas??

Add your idea here!!!


SVTCHI SIAMO e Richieste VII FP

1. FRASCATI: A. Annovi (art. 36-PI, SVT upgrade ex-project leader), S. Torre (Ass. Ric., SVT operations manager)

2. PISA: P. Giannetti (Dir. Ric.), M. Dell’Orso (Prof. Ass.), L. Sartori (M. Curie OIF, AM chip designer, L2 cal. upgrade technical coordinator)

3. FERRARA: storica collab. Ape-CDF per AM standard cell. F.Schifano (RU), R. Tripiccione (Prof. Ord.) – Invitato a partecipare il gruppo Babar – speriamo che accetti

IDEAS tot 400 keuro/year (5 years):1. Man Power for 5 year: Frascati PI + 2 art. 23

– Pisa 1+1/2 art. 23 – Ferrara 1+1/2 art. 23 = 56 + 44 * 5 = 275 + 55 (20% over.) = 330 keuro

2. 70 keuro/year AM chip subcontractors. Prototype using MPW with very challenging technology (~350 keuro tot)

3. Missioni/conferenze/… = 0 euro


SVT

BACKUP SLIDES


SVTTracking processing time

With Associative Memoryprocessing time proportional to occupancy

10x luminosity --> 10x AM hardware

With CPUsprocessing time proportional to combinatorialharder to predict!Hardware needs increase exponentially with luminosity!10x luminosity --> e10 times CPUs….


SVT

Layer 0: ~25 fibers bringing ~40 Hits/12 ns... ...

AM EV0

AM EV1

AM EV40

...

1 Hit/10 ns

1 Hit/10 ns

1 Hit/10 ns

1 FIFO/fiber

From otherlayers

From otherlayers

From otherlayers

Distribute hits into different sets of

registers depending on Event #

FPGA

The switch board

1 switch / layer

layer 0

AM latency =passthrough time (10bx?)+ # hits * clock period

AM clock (>100MHz)Here is were # of hits

and its fluctuations matter


SVTVIRTEX 5: 65 nm- 550 MHz devices

XC5VSX95T: 160 x 46 CLB Array (Row x Col)

Each Slice:1. 4 6-input

Luts or RAM or SR

2. 4 FFs3. Wide MUXs4. Carry logic

160

46

244 39kbits BlockRams or Fifos+ 640 DSP Slices (organized in columns) ~1200 euro


SVTB-tagging @ ATLAS (w/o & w/ FTK)

LVL2

EF offline

ATLAS T&P march 2007

LVL2 vs offline difference10 times less rejection

EF vs offline difference being investigated

with Fast-TracK offline b-tag performances @LVL2

ATLAS TP 31/3/2000

0.6

100

10

1000

b

Ru


SVT

L=2x1033 cm-2 sec-1

HLT selection @ CMS H(200,500 GeV) 1,3h± + X

0.4

0.5

0.6

0.7

0.8

0.9

1.

0 0.02 0.06 0.1 0.14

(QCD 50-170 GeV) (H(200,500 GeV)

1,3h+X)

mH=500

mH=200

TRK tau on first calo jets

Pix tau on first calo jet

Staged-Pix tau on first calo jet

TRK tau on both calo jets

Calo tau on first jet

0.0070.004

Efficiency & jet rejection could be enhanced by using tracks before

calorimeters.


SVTbbH/A bbbbATLAS-TDR-15 (1999)

MA (GeV)

tan

200

Analysis:4 b-jets |j|<2.5 PT

j > 70, 50, 30, 30 GeV efficiency 10%

Effect of trigger thresholds(before deferrals)

ATLAS + FTK triggers

13%3b leading3J + SE200

8%3 b-tagsMU6+ 2J

Effic.LVL2LVL1 As efficient as offline selection:full Higgs sensitivity A

TL-COM-DAQ-2002-022


SVT

**** di-muon triggers for rare decays

LVL1: 2 RoI pT () > 6GeV (~500 Hz @ L=1033cm-2s-

1)

LVL2: Confirm each RoI from LVL1

In precision muon chambers Combine with Inner Detector

track Mass cut 4 GeV < M()<

6 GeVEF: Refit ID tracks in Level-2 RoI

Decay vertex reconstruction

Transverse Decay length cut:

Lxy > 200m

Efficiency estimation L2/EF:bb+- for both pT>6 GeV– 70% of B +-

– (60% of B K* + -)

Online reconstruction of di- mass, (MeV)

B K* +

-

B+ -Not normalized

BEAUTY 2006 talk


SVT

3cm15cm150cm

Outerdriftchamber

Silicon stripdetector

Siliconclose-up

Impact parameter

Beam spot

1mm

Zoom-inInput (every Level 1 accept):• XFT trajectories• silicon pulse height for each channel

Output (about 20 microseconds later):• trajectories that use silicon points • r- tracks• impact parameter: (d)=35 m

SVT @ CDF Level 2 -> next generation SVT @ Level 1

AMalgo


SVTLepton triggers @ level 1

match between a muon stub orcalorimeter signal with XFT track

80 140 200 Luminosity (xE30 cm-2s-1)

Level 1 rate (Hz)

600Hz

Level 1 mu Pt>4 GeV


SVT

The Event

Pattern matching in CDF (M. Dell’Orso, L.Ristori 1985 -..)

...The Pattern

Bank

The pattern bank is flexibleset of pre-calculated patterns:• can account for misalignment• changing detector conditions• beam movement • …


SVT

•Dedicated device: maximum parallelism•Each pattern with private comparator•Track search during detector readout

• If you can read it out you can track it!

AM: Associative Memory

Bingo scorecard

AM = BINGO PLAYERS

HIT # 1447

PATTERN NPATTERN 1PATTERN 2

PATTERN 3

PATTERN 5

PATTERN 4


SVT Associative Memory (AM) for

pattern matchingM. Dell'Orso and L. Ristori, “VLSI structures for track finding”,

Nucl. Instr. and Meth., vol. A278,

pp. 436-440, (1989).1 register1 comparator1 match FF/ layer/ pattern


SVT

5 CLB (come Block RAM): 32 into each column x 20 columns

DSP SliCEs


SVT

SVT FiFo35 MHz

II FiFo70 MHz

Lay0-Ram or SR

Lay1- Ram or SR

Lay2- Ram or SR

Lay3-Ram or SR

Lay4-Ram or SR

XFT-Ram or SR

Comb - FiFo

7 Mult+7

6 Mult+6

6 Mult+6

6 Mult+6

6 Mult+6

6 Mult+6

37 DSP slices/Equation.For 6 equations37x6= 222 DSP slicesChoose best chi**2

Each equation is calculated 6 times (all layers and 1 SI-missing)

6 input LUTInside Slices

BLock RAMs

6 fit in parallelo/Wedge

Choose the best

chi**2


SVT

FPGA40 JTAG 4 wedge connectors on

each mezzanine possible up to 6x4=24 fits in parallel

3 mezzanines = 12 wedges4th mezzanine large memory for non-linearity corrections


SVT

ILAY OADDOR

CLB

READOUT

LOGIC

SELEXTOROLAY

IHIT

OHIT

PATTERN

QUARTET

INIT EVENT

QUARTET Priority Encoder

HREG0

H R E G 1

HREG2

LayREG

1995: 0.35 FPGA same AM than 0.7 full custom

Very regular layout and routing. 95% used logicSame timing performances of the full custom chip!

Since then Cam has been introduced into FPGA.

We use FPGA AM in the Road warrior to delete SVT ghosts (two candidate tracks differing only for empty layers

Pattern


SVTAM projectsSVT: Silicon Vertex Trigger @ CDF (L. Ristori et al.)• first AM application• extremely successful Bs mixing, ACP B->hh’, Z->bb, bbH->4b• proven to be easy to upgrade (1-2 years turn around time)

FTK: FastTracK @ ATLAS (preparing a proposal: P.Giannetti-Pisa, M. Shochet, YK Kim- Chicago, T. Liss - Illinois et al.)

• Full tracker reconstruction @ L2 @ full L1 out rate 100kHz• Offline quality (see next slide) and efficiency

???: L1 tracking @ CMS (F.Palla proposal)• tracking at 80MHz• momentum measurement with a few (4?) “pixel” layers

SLIM5: L1 tracking @ SuperB (F. Forti, M. Giorgi et al.)• R&D to develop MAPS sensor integrated with AM trigger


SVTAM synergy

Several AM based projects --> great advanteges:• share hardware: develop a single new AMchip

• we are applying for CE funds for a prototype

• share expertise: many people are/have been involved in SVT or FTK

• share tools: e.g. trigger simulation• share mantainance (spares/diagnostics...)• makes the project easier and cheaper

We can help providing training and tools.To start this very “rewarding” business: you will need a smaller motivated group in charge of the project!


SVTHow to process all data @ bx rate?1. Take advantage of AM input bandwidth

• Currently 50 MHz (hits/sec/layer)• Hits for different layers are loaded in

parallel • Next version > 100MHz (90nm tech. &

pipelining)2. Parallelize by sectors

1. ~80 detector sectors are processed in parallel

2. implies a minimum Pt threshold (e.g. >5 GeV)• Parallelize different events

• for each sector 40 AMchips process 40 events in parall.

• need switch boards1. housing ~40 AMchips 2. with FPGAs used as data switch for

AMchips

Caveat: need to take care of # of hits fluctuations


SVTswitch board numbersAll info here TBC with simulation and R&D!

•80 switch boards• 1 / -sector

• 80 fibers / board• assume 5Gbps each

• 40 AMchip / board• now we can fit 32 AMchips in one 4th of a 9U VME board

• 4 FPGA switches (1/layer)•Each receiving ~20 fibers, i.e. ~100Gbps•40 outputs: one per Amchip•Possible with today’s FPGAs

32 AMchips


SVTThe CDF Tracker

TIME OF FLIGHT

B field = 1.4 T

Longitudinal viewTransverse view


SVTCDF Trigger Architecture

Drift chamber trackingLepton reco/track matching

…

Silicon trackingSecondary vertex

selection…

CPU farmFull event reconstruction

with speed optimized offline code

Level 1 pipeline: 42 clock cycles

Level 1Trigger

L1Accept

Level 2Trigger

Level 2 buffer: 4 events

L2Accept

DAQ buffers

L3 Farm

Level 1•7.6 MHz Synchromous Pipeline•5.5 s Latency•30 kHz accept rate

Level 2•Asynchromous 2 Stage Pipeline•20 s Latency•1000 Hz accept rate

Mass Storage (~100 Hz)

Raw data, 7.6 MHz Crossing rate

SVX read out after L1

SVT here

XFT here


SVTHadronic B decays

L1

Two XFT tracks

Pt > 2 GeV; Pt1 + Pt2 > 5.5 GeV

< 135°

Two body decays Many body decays

L2

Validation of L1 cuts with >20°

100 m<d0<1mm for both tracks

Lxy > 200 m

d0(B)<140 m

Validation of L1 cuts with >2°

120 m<d0<1mm for both tracks

Lxy > 200 m

d0(B)<140 m

B -> h h’ Bs mixing

Two trigger paths

Essential for Bs mixing measurement!


SVT

Roads1. Find low resolution track candidates called “roads”. Solve most of the pattern recognition

2. Then fit tracks inside roads.Thanks to 1st step it is much easier

Super Bin (SB)

Too much large AMTracking in 2 steps

OTHER functions are needed inside SVT: Hit Buffer + Track fitter + Hit Finder


SVTSVT Performance

-500 -250 0 250 500

(m)

35m 33mresol beam = 48m SVT

Impact parameter

90% efficient given a fiducial offline track with SVX hits in 4 layers


SVTPromise is promise

What we promised…. From SVT TDR (’96) using offline silicon hits and offline CTC tracks

~ 45 m


SVTSVX only

Good tracks from just 4 closely spaced silicon layers

I.p. as expected due to the lack of curvature information

impact parameter distribution

~ 87 m

Silicon onlyno XFT


SVTSVT Upgrade (done, fall 2005)

0 20 60 100 140 180 Luminosity (xE30)

original system

upgradedsystem

Timing (s

)

L1 bandwidth 18kHz -> 30kHzNow stable w.r.t luminosity

•Need to process more complex events in less time•Same architecture as original system•Better pattern recognition resolution

•New AM chip32K512K patterns•fewer combinations/road

•Faster components•Use custom but general purpose Pulsar boardshttp://hep.uchicago.edu/~thliu/projects/Pulsar/•Short development time

•Parassitic test & validation of boards

Take good data @ high lumi & more data @ low lumi

NSS2005 Conf. Rec. Vol.1, 603


SVTSVT flexibility for new ideas

SVT designed to be flexibleprogrammable patternsLook Up Tables & FPGAsmodular system

Pulsar programmable board with SVT connectorsimplement new functions in ~ a few months

Design system for easy testing

Extensive on-crate monitoring during beam


SVT

Track dataROB

Track dataROB

Raw dataROBs

~Offline quality Track parameters

~75 9U VME boards – 4 types

SUPER BINSDATA

ORGANIZERROADS

ROADS + HITS

EVENT # N

PIPELINED AM

HITS

DO-board

EVENT # 1

AM-board

2nd step: track fitting

Inside Fast-TrackPixels & SCT

DataFormatter

(DF)

50~100 KHzevent rate

RODsRODs

cluster findingsplit by layer

overlap regions

RW

Few CPUs

NEW

S-links


SVT

Curvature Impact Parameter

Cot()

Z Particle Type

FTKsim versus iPatRec – Efficiency

M. Dell’Orso, F. Crescioli, G. Punzi, G. Volpi, G. Usai


SVT

xi

Non-linear geometrical constraint for a circle:

F(x1 , x2 , x3 ,

…) = 0

But for sufficiently small displacements:

F(x1 , x2 , x3 , …) ~ a0 + a1x1 + a2x2 + a3x3 + … = 0with constant ai

(first order expansion of F)

From non-linear to linear constraints


SVTConstraint surface


SVTOnline beamline fit & correction

d

phi

d

Subtracted

Raw <d> = Ybeamcos – Xbeamsin

Measure beam width as well --> input to Accelerator Division

x

y

d

Transverse view


SVTAM++


SVTPulsar in SVT++

Implement new boards with Pulsars:•Fast enough to handle the new amount of data•SVT interface built in•Developers can concentrate on firmware (= board functionalities)

The Pulsar board is a programmable board: 3 powerful FPGAsembedded RAM

all CDF connectors modular mezzanines

S-link I/ORAM extension

Pulsar @ CDF --> FPGAs @ board devel.

RAM mezzanine 4Mx48bits


SVT


SVT

ATLAS TDR 016


SVTWhy SVT succeeded

– Performance: • Parallel/pipelined architecture• Custom VLSI pattern recognition• Linear track fit in fast FPGAs

– Reliability:• Easy to sink/source test data (many boards can self-test)• Modular design; universal, well-tested data link & fan-in/out

• Extensive on-crate monitoring during beam running• Detailed CAD simulation before prototyping

– Flexibility:• System can operate with some (or all) inputs disabled• Building-block design: can add/replace processing steps• Modern FPGAs permit unforeseen algorithm changes

– Key: design system for easy testing/commissioning


SVTSector segmentation

• Subdivide the (pixel) detector in many sectors – Keep data volume limited in each sector

• Combine information from at least 3 layers out of 4 in each sector – Momentum resolution of ~ few (<10)% at

10 GeV/c – Granularity driven by the minimum

measurable pT for triggering purposes, without loosing efficiency• ~80 sectors at the innermost radius

~ 4.5° matches to a module of 2 cm width – Well covering the bending of a track of 5

GeV pT and above

• Larger sectors with increasing radii – Match the sensors widths

• This plan match with AMchip features!!!

26 cm

34 cm

42 cm

50 cm

F. Palla (LECC06 workshop)


SVTConceptual design

AM EV0

AM EV1

AM EV40

...

Layer 0: ~25 fibers bringing ~40 Hits/12 ns

1 Hit/10 ns

1 Hit/10 ns

1 Hit/10 ns

From otherlayers

From otherlayers

From otherlayers

Distribute hits into different sets of

storage units depending on EVent #

Parallel INSerial OUT

...Parallel INSerial OUT

Parallel INSerial OUT

1 FPGA

From Detector



SVTOccupancy studies

• GEANT4 simulation of pixelized tracking layers– Simulated 3500 minimum bias using latest Pythia settings

events and group into chunks of 100 events per bunch crossing and 250 t-tbar events

– Use current CMS layout (material budget) but different sensors granularity

Layer Layer No.No.

Radius (cm)

Hit/module/bxa

No. detectors in

Hits/sector/bxª

Data rate*/module (Gbps)

Data rate*/sector (Gbps)

No. data links†/layer

11 26 3.1 82 43 5 69 110022 34 8.7 36 78 14 125 90033 42 5.8 44 49 8 78 70044 50 3.7 52 34 6 55 600

ª average number on minimum bias events, t-t will contribute on average<<1 hit/det*20 bits/hit† for a data link speed of 5 Gbps

Current links in CMS TIB Silicon Strip: 2000 @ 26 cm - 2600 @ 34 cm


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SVT INFN LNF - 28 Marzo 2007Alberto Annovi1 STARS: Supercomputers for Trigger Analysis and Real-time...

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