December 2002 1

DZERO Operations

Jerry BlazeyNorthern Illinois University

December 2002 2

Detector• All elements in place• Commissioning:

– Forward preshower (FPS)– Proton detector (FPD)– L1 Central Track Trigger (CTT)

• Silicon Track Trigger (STT) under construction.

• Change to ethernet-based DAQ very successful

December 2002 3

Operations/Analysis• Early September set a series of operational

and analysis goals for fall/winter – highly successful!

• Operations:– 50pb-1 or more available for Moriond.– Recording physics data with >75% efficiency.

• Intense work on reconstruction/processing – Upgraded version of reconstruction, improvements

in tracking efficiency, object identification, etc– Reconstruction farms in place for high luminosity.

• Physics analyses well underway for spring conferences

December 2002 4p-side pulse-height (ADC)

Silicon Microstrip Tracker Status

Track finding in barrels and disks

Barrels+ disks

Barrelsonly

Run II data

4 barrel layersaxial + stereo strips

p-side pulse height1 mip ~ 25 countsSignal/Noise ~ 12Layer efficiency ~ 97%

H, F Disks/wedges

December 2002 5

Silicon Status• Radiation

– Increase of bias current measured and consistent with expectations

– Infers depletion voltage exceeds specifications @ 4fb-1

• Active Ladders/WedgesDevice Oct 01 Feb

NowLadders: 93.4% 93.1% 88.4% F-wedges: 92.7 91.5 91.3H-wedges: 86.0 86.0 85.4

– No loss in fiducial volume.– Some recovery expected during Jan access.

Layer 1,2 Bias Current vs Luminosity

4

5

6

7

8

0.02 0.04 0.06Integrated Luminosity (fb-1)

Bia

s C

urr

ent

December 2002 6

Scintillating Fiber Tracker• 8 axial, 8 stereo layers

fully instrumented• VLPC readout• Performing well

• good light yield• layer > 98%

Occupancy matches expectations

track

Light yield

December 2002 7pT (GeV)

Tracking Performance

Survey-only alignment constants

Significant improvement expected from alignment with data in near future

width = 36 m(beam) = 30 m

= 20 m

track

x

yImpact ParameterResolution

Impact parameter

KS + –

December 2002 8

Muon System

Connect tracks

J/ +-scintillator

Muon System

standalone = 750

MeV

Match to CFT

tracks = 83 MeV

• Three layers of scintillator planes for triggering• Three layers of drift tubes for precise track measurement

shieldingChannels:MDT/PDT - 99.5%

Scintillator - 99.9%Recover ½ in Jan

Shutdown

December 2002 9

Calorimeter

J/ e+e-

Run II High ET 3-jet

eventET

: 110, 240, 310 GeVEt

miss : 8 GeV

Liquid argon calorimeterwith uranium absorber

Calorimeter Level 1 triggers for electrons and jets: rates agree with Monte CarloChannel Count: 97%

Channel Count: 99.9%

December 2002 10

Extensive forward coverage: 1.5 || 2.5 Extruded triangular scintillator strips with

embedded WLS fibers: 14,988 channels u,v Stereo Layers with 2X0 Lead Absorber Signal: Detector clear fiber waveguides

VLPCs and Analog-Front End (AFE) Readout

Forward Preshower Detector

L0, FPS, ICD on EC-head

y

x

Offline FPS Reconstruction

System instrumented June 2002

Offline reconstruction using matched u, v clusters and energy correlation requirement

Performance being optimized jointly with entire DØ VLPC detectors (CFT, CPS)

December 2002 11

Forward Proton Detector

t

Elastic scattering dataScintillating fiber detector inside

•Ten pot operation in readout will begin after January shutdown •Eighteen pot operations requires funds for PMTs

• Routinely and reliably insert pots in every store• Detectors perform as designed (good efficiency, resolution) • Have observed diffractive and elastic events • Heretofore standalone, integrating into trigger/daq

December 2002 12

Trigger/DAQ

• L1– Cal & Muon available– CTT commissioning underway

• L2– Operating with CAL, Muon, Global– CTT & PS Commissioning underway– STT in assembly and installation– Input rate expansion early ’03 w/ alpha

replacements • DAQ

– Debugging FE readout– Last summer successfully installed an

ethernet/commodities based DAQ. – Meets 1 kHz L2 accept specification.

Spec: 5 kHz

1000 Hz 50 Hz

tape

Current: 1.2 kHz 50 Hz 1000 Hz

Level 2Level 1 Level 3

Operating: 0.7 kHz 50 Hz 300 Hz

December 2002 13

L1CTT• Discriminator input available• Providing tracks to L1muon• L1 terms (in triggers now)• L2 and track and preshower

cluster lists

L1 terms Occupancy

December 2002 14

STT

Silicon Trigger Card (STC)

• 30o azimuthal units, 6 crates• Common Motherboard w/

PCI communication– Fiber Road Card (FRC)

receives and fans out CTT tracks

– Silicon Trigger Card (STC) receives silicon data and filters silicon hits using CTT tracks

– Track Fit Card (TFC) fits trajectory

• Huge progress this year, from prototypes to complete production

• Commissioning 1st sector at DØ – Firmware debugging– Interface with DØ

systems• Operational Spring 2003

December 2002 15

Luminosity (Through 11/01/02)

(Commissioning etc.)

CFT Fully Instrumented

CFT Axial Instrumented

December 2002 16

11/16/02

Delivered: 1.00 pb-1

Utilized: 0.98 pb-1 (98%) To Tape: 0.86 pb-1 (86%)

December 2002 17

1685163.4hrs10E30Live: 87% Tape: 35hz

1685154.0hrs15E30Live: 90%Tape: 31hz

1685143.7hrs15E30Live: 86%Tape: 36hz

1685134.0hrs20E30Live: 86%Tape: 33hz

1685104.0hrs25E30Live: 90%Tape: 33hz

Store 1995

December 2002 18

11/11-17/02

Delivered: 5.8 pb-1

Utilized: 5.3 pb-1 (92%) To Tape: 4.2 pb-1 (72%)

December 2002 19

Integrated Luminosity (Since CFT Fully Instrumented)

Month Del(pb-1) Tape(pb-1) Eff(%)June 1.3 0.5 39July 9.2 5.1 55Aug. 11.1 6.1 55Sep. 16.5 10.0 61Oct. 21.5 13.8 64Nov 20.6 14.9 73

Steady Improvement: Downtime 10% to 2% FEB/L2 Busy DecreasingTotal

Delivered: 80 pb-1

To Tape: 50 pb-1

December 2002 20

Capabilities• Trigger List now has ~100 triggers

– Electron, dielectron,muon, dimuon, jets…

• Runs comfortably up to 4E31 cm-2s-1

• Will keep pace with luminosity growth as – L1CTT completed – L2 CPUs added– L2&L3 filters

expanded.

December 2002 21

Remote International Monitoring for the DØ Experiment

Fermilab

NIKHEFAmsterdam

Detector Monitoring data sentin real time over the internet

DØ physicists in Europe use the internet and monitoring

programs to examine collider data in real time and

to evaluate detector performance and data

quality.

They use web tools to report this information back to their

colleagues at Fermilab.DØ

The online monitoring project has been developed by DØ physicists and is coordinated by Dr. Pushpa Bhat from Fermilab. Jason Webb, a DeVry University, Chicago, undergraduate student is helping develop and maintain the interactive tools for the remote physicists.

9 am

2 am

DØ detector

December 2002 22

January Shutdown

• De-rime VLPC liquid-helium system

• Install bottom muon chambers• Maintenance of cyrogenic systems• Study SMT electronic shielding

between cryostats.• Channel recovery: SMT, Muon, Cal

December 2002 23

Run IIb Upgrade• The present detector was designed for ~ 2fb-1 and 2 1032 cm-2 s-1

• The Director has set the goal of accumulating ~10-15 fb -1 before the end of the decade– Exceeds radiation tolerance of existing silicon detector– Requires higher luminosities, ~ 5 1032 cm-2 s-1, trigger upgrades

Replace Silicon Detector with a more radiation-hard versionImprove impact-parameter resolution (b-tagging) through additional layers and smaller beampipeMaintain good pattern recognition over || < 2

Upgrade TriggerShift functionality upstream and increase overall Level 1 trigger capability – contain rates, dead time - Calorimeter clustering & digital filtering- Enhance track trigger to respond to increased occupancies- Calorimeter cluster match with trackIncremental Upgrades to Level 2, Level 3 Triggers and online system

September 2002 Lehman Review recommended baselining of Run IIb upgrades.

December 2002 24

Run IIb Silicon Detector

• Single sided silicon, barrels only

• Detector installed in two halves inside collision hall in ~7 month shutdown

• Inner (vertexing) layers 0, 1– Axial only– mounted on carbon

support • Outer (tracking) layers 2-5

– Axial and stereo (tilted sensors)

– Stave structures• Prototyping essentially

done.

GEANTmodel

December 2002 25

Run IIb Silicon Performance

b-tagging performance studied with full GEANT simulation and pattern recognition

Performance meets the physics requirements (based on the Run II Higgs/SUSY workshop)

mistag rate 1-2%

b vs. Ejet

b vs. jet

b vs.fraction ofdead ladders

Run II workshop assumptions for tight and loose tags

December 2002 26

Trigger RatesCore trigger menu, simulated at L=2e32, t=396 ns

Total rate: ~30 kHz 3.9 kHz

Trigger Example Physics Channels

L1 Rate (kHz) (no upgrade)

L1 Rate (kHz) (with upgrade)

EM (1 EM TT > 10 GeV)

eW

jjeWH

1.3 0.7

Di-EM (1 EM TT > 7 GeV, 2 EM TT > 5 GeV)

Z ee ZH eejj

0.5 0.1

Muon (muon pT > 11 GeV + CFT Track)

W WH jj

6 1.1

Di-Muons (2 muons pT > 3 GeV + CFT Tracks)

Z , J/Y ZH jj

0.4 < 0.1

Electron + Jets (1 EM TT > 7 GeV, 2 Had TT > 5 GeV)

WH e+jets tt e+jets

0.8 0.2

Muon + Jet (muon pT > 3 GeV, 1 Had TT > 5 GeV)

WH +jets tt +jets

< 0.1 < 0.1

Jet+MET (2 TT > 5 GeV, Missing ET> 10 GeV) bbZH

2.1 0.8

Muon + EM (muons pT > 3 GeV+ CFT track + 1 EM TT > 5 GeV)

HWW, ZZ < 0.1 < 0.1

Single Isolated Track (1 Isolated CFT track, pT > 10 GeV) H tt, W

17 1.0

Di-Track (1 isolated tracks pT > 10 GeV, 2 tracks pT > 5 GeV, 1 matched with EM energy)

ttH 0.6 <0.1

December 2002 27

Conclusions

• DZERO up and running• Upgrade set to go…

• Ready for and anticipating increasing luminosity

December 2002 28

Cause for Concern:Retention of Expertise

• Have seen a decreasing number of experts: already insufficient for calorimetry and muon tracker, STT next.

• Multiple Causes– Poor perception of “detector people”– Institutional “fatigue”– Changing careers– Reduction in base program support– Uncertain international politics

• Governmental agreements languishing• Difficulty obtaining visas

• Experts predict a worsening problem – will impact data quality and efficiency

• Requires action by collaboration & funding agencies

December 2002 29

Calorimeter Experts

• Current: ~ 3-4 FTE already inadequate– Parua, SUSB: current coordinator– Schamberger, SUSB: electronics– Tuts, Columbia : project manager– Groer, Columbia : previous coordinator– Gao, Columbia: student– Fu, Columbia :student– Bassler, Paris : previous coordinator

• Anticipated ~2 FTE– Beauceron, Paris : expert until 9/03– Princeton Postdoc: incoming 2003.– SUSB Postdoc: incoming 2003?– Schamberger, SUSB

December 2002 30

Muon Experts• Current, already inadequate, diminished:

– General: Diehl(Fermi), Denisov(Fermi), Shpakov(Northeastern Postdoc)

– PDTs: Marshall(Indiana,retires), Wobisch(Fermi Postdoc)– MDTs: Tokmenin(JINR, no visa), Yatsunenko(JINR) – Pixels: Evdokimov(IHEP, no visa), Vasilyev(IHEP, no visa) – Central trigger counters: Evdokimov(ITEP), Ito(Fermi),

Doulas(Northeastern Postdoc)– Electronics: Baldin(Fermi), Hansen(Fermi)

• Difficult to predict next year…depends on visa situation, agreement with Russia, retirement replacements.

December 2002 31

Thoughts on Solutions

• Increase prestige of positions.• Institutional requirements to contribute

FTE personnel, this requires attention and effort on everyone’s part with respect to international agreements and visas.

• Encouragement/guidance from funding agencies – U.S. groups must have adequate support from the base program to operate detectors

December 2002 32

In response to need for increased and retained expertise and remaining commissioning tasks– Request assistance with

agreements and visas.– Prioritized requests for additional

NSF/DOE support:• Postdoc support for calorimeter (e.g.

Princeton, Louisiana Tech., Michigan State)• Faculty/postdoc support for L2Beta (Virginia)• Travel support for L2STT (Boston)• Supplemental support for computing

(Michigan)