DD

Commissioning Results of the Commissioning Results of the DDØØ Tracking System Tracking System

Harald Fox

Northwestern University

May 24, 2002

Design Installation and

Commissioning Tracking/Vertexing

Results

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DPF 2002 H. Fox 2

The Fermilab Tevatron Collider

Main Injector & Recycler

Tevatron

Chicago

p source

Booster

p

p

p p

1.96 TeV

CDF

DØ

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DPF 2002 H. Fox 3

Calorimeters Tracker

Muon System

Beamline Shielding

Electronics

protons

20 m

antiprotons

The DØ Detector

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DPF 2002 H. Fox 4

Tracker Design

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DPF 2002 H. Fox 5

SMT Design

4-layer barrel cross-sectionBarrels F- Disks H- Disks

sngl/dbl sngl + dbl double single

Stereo 0, 2, 90 +/ -15 +/ -7.5

Channels 387072 258048 147456

Modules 432 144 96

Rin/Rout 2.7/ 9.4cm2.6/ 10.5cm 9.5/ 26cm

6 Barrels

12 F Disks

4 H Disks

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DPF 2002 H. Fox 6

SMT Design

Require good 3D track reconstruction performance for high-pT (top, Higgs, EW, NP) and low-pT (B) tracks out to || < 3Momentum resolution less than 10% at pT = 1 GeV/cImpact parameter resolution within 30 m

Forward H disks are employed to achieve these resolutions at high ||

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DPF 2002 H. Fox 7

SMT Readout Electronics

Interface BoardsRefresh signals and adjust timingPower management and monitoring

SEQencersManagement of SVXConversion to fiber optics

VRB (VME Readout Buffer)

Data buffer pending L2 trigger decision~ 50 Mb/s/channel5-10 kHz L1 accept 1 kHz L2 accept rate

Pipeline Control Logic

Analog Pipeline:

128 channel

32 cells

128

In

teg

rato

rs

AD

C C

om

par

ato

rs

Sp

arsi

fic

atio

n F

IFO

I/O

ADC ramp and

counter

Analog section Digital section

To

Sil

ico

n D

etec

tor

To

Re

ado

ut

Sy

stem

SVX IIe Chip128 channel, 32 pipeline cells8 bit ADC with sparsification106 MHz digitization, 53 MHz readoutRadiation hardDeveloped by LBL/Fermilab group

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DPF 2002 H. Fox 8

CFT Design

8 layers of axial and 3° stereo fibers mounted on carbon fiber support cylinders.20cm < r < 51cm.

76,800 individual fibers.Diameter: 835μm. Length: 1.8/2.6m.The interlocked fibers are precisely positioned. Hit resolution about 100μm.

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DPF 2002 H. Fox 9

CFT Readout Electronics

High gain: 17k – 65k e per photonAFE boards provide

Bias voltageTemperature controlFast digital trigger informationAnalog pulse information (SVX)

SEQ + VRB readout as SMT

~8-11m long wave-guides to Visible Light Photon Counter (VLPC, solid state photo multiplier).VLPCs are operated at 9K. Quantum efficiency: 80%. 1 mip ~ 8 photo electrons: Excellent S/N!

0 pe

2 pe

3 pe4 pe

1 peLED Calibration

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DPF 2002 H. Fox 10

Low Mass Cables

Installation

Fiber tracker installation Cylinder installation was completed on 12/20/00

A ½ cylinder of 3 barrels and 6 F disks was inserted into each end of the CFT bore

H Disk installation was completed on 2/6/01The cabling (~15,000 connections) and electronics installation was completed in May 2001Axial Fiber Tracker electronics installed in November 2001Stereo electronics completed April 2002

SMT cylinder

Calorimeter

High Mass Cables SMT

Interface Boards

Wave guides

Cryostat with AFE boards

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DPF 2002 H. Fox 11

SMT Charge Collection

Cluster charge (corrected for track angle): 1 mip ~ 25 ADC counts. Noise < 2ADC counts.

p-side pulse-height (ADC)

n-si

de p

ulse

-hei

ght

(AD

C)

Charge correlation between p- and n-side of a detector

p-side pulse-height (ADC)

Lorentz angle: The charge deflection due to the magnetic field

fract

ion

of1

strip

clu

ster

s

Local track incidence angle

φL =4.5°

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DPF 2002 H. Fox 12

CFT Commissioning

Light yield per sector vs pseudorapidity η

Zee candidate event.Mass 89.9GeV/c2

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DPF 2002 H. Fox 13

Tracking and Vertexing

DCA

track

x

y

Impact parameter resolution SMT track

CFT track

CFT-SMT track matching

Vertex measurements

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DPF 2002 H. Fox 14

Physics Results

We candidates

ET(cluster)/pT(track)

E/p for Weν candidates KS π+π- cand.

First evidence for B decaysJ/Ψ μ+μ- candidates

Z μ+μ- cand.

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DPF 2002 H. Fox 15

Conclusions

DesignThe DØ tracking detectors are designed to have a good impact parameter resolution over a wide range of η.

CommissioningThe SMT was the first major DØ Upgrade detector system fully operational for Run 2A. About 95% of the channels are available for readout.

ResultsCalibration, beam measurement, and alignment results are looking promising.Physics results coming in.Noise studies, tracking refinements, etc. continue.

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The work of many people...

…thanks to all of them.

The DØ Collaboration

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DPF 2002 H. Fox 17

Data p-side

5.4L

Lorentz angle

Lorentz angle is different for p- and n-sides Lorentz shift is not visible for 90 deg stereo stripsLorentz shift is large for 2 deg stereoLorentz angle can be measured in local phi distribution for one strip clusters

Measurement is NOT affected by alignment or reconstruction

L

h+

e-

P-side (axial)

Phi distribution for one strip clusters

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DPF 2002 H. Fox 18

SMT Design: Stereo Angles

Ladders3-chip: 72 single-sided, axial ladders in the two outer barrels6-chip: 144 double-sided, axial/90° ladders in the four inner barrels9-chip: 216 double-sided, axial/2° ladders in all barrels

WedgesF Disks: 144 double-sided, ±15°, 6+8 chip wedgesH Disks: 96×2 back-to-back single-sided, ±7.5°, 6 chip wedges

9-chip ladder9-chip ladder

H wedgeH wedge

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DPF 2002 H. Fox 19

Production & Assembly: Testing

Probe TestDebug bad strips (broken capacitors), bonds, chips, etc.Determine the V-I characteristics of the sensorsMeasure V-max p-side breakdown voltage (micro-discharge effect)

Burn-inBias the ladder or wedge and test the readout for 72 hoursMeasure pedestals, noise, gain and check sparse readout

LaserExpose biased detectors to a narrow laser scanMeasure the depletion voltage and leakage currents and identify dead channels

Readout tested again after the detector has been mounted.

V-max

Fail

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DPF 2002 H. Fox 20

SMT Readout: Data Flow

PlatformPlatformPlatformPlatform

SEQ

SEQ

SEQ

SEQ

SEQ

SEQ

3/6/8/9 Chip HDI

Sensor

8’ Low Mass Cable

VRB Controller

Optical Link1Gb/s

V

B

D

V

R

B

V

R

B

V

R

B

68k/PwrPC

Bit3

PC

SDAQL3MPM

VME

1553

HV / LV

Adapter Card

I,V,T Monitoring

KSU

Interface Board

25’ High Mass Cable (3M/50 conductor)

CLKs CLKs

SEQController

Serial Command Link

~19’-30’ High Mass Cable (3M/80 conductor)

Detector volumeDetector volumeDetector volumeDetector volume

Counting HouseCounting HouseCounting HouseCounting House

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DPF 2002 H. Fox 21

Alignment: Residuals

SMT-only tracking with at least 4 hitsMagnet off dataSimilarity of residuals from reconstruction with ideal and survey geometries indicates excellent internal alignment of the SMT

Ideal GeometryIdeal Geometry Survey GeometrySurvey Geometry