Status of the Central Fiber Tracker(CFT)

Central Preshower(CPS)and Forward Preshower(FPS)

or CFT/PS for shortDrew Alton

University of Michigan

Outline

Introduction History Status

CFT Efficiency CPS results FPS progress Issues

Plans Conclusions

Introduction

~100,000 Channels CFT (76,800 channels)

8 axial layers 8 stereo layers

4 u and 4 v

CPS (7680 channels) 1 axial layer 2 stereo layer

1 u and 1 v

FPS (14,884 channels) 2 MIP layers

1 u and 1 v 2 shower layers

1 u and 1 v

PS and CFT readout

PS

CFT

Scintillating or wavelength

shifting fiber

Waveguide

VLPC cassette

Electronics

CryostatAFE backplane

Data to Level 3

AFE boards

Sequencer

G-Link Cable

VTM

LVDS cable to L1

VRB

Led Illuminated

Recent History

July-Oct. 7, 2001 2 prototype AFE’s on Platform

Jan 21, 2002 CFT Axial complete (again)

April 17, 2002 CFT and CPS complete

June 29, 2002 FPS complete

VLPC Cryostat

Cold block stable to 100mK Cassettes stable to 50mK Impossible to state how important this is It’s a statement on how well behaved things are

that no one (except GG and RR) thinks about this anymore

Issues overcome this year

AFE Power supply ‘flickers’ and trips Developed and improved calibration techniques Latching boards Readout turning off Split pedestals Non-uniform pedestals Pedestal moving when applying zero-suppression

threshold Move readout by 264 ns

Everyone

Pedestal Stability

Pedestals for an SVX as a function of time.

Mean of the 64 channels

RMS of the 64 means (uniformity).

Mean stable to <1 ADC for months

RMS stable to < 0.5 ADC for months S

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J. Warchol, Y. Jiang

Data Quality Efforts

Make a ‘hit map’ (fired fiber distribution)

Fill a histogram with # of fires for each strip in a layer.

Find mean and RMS Define ‘hot’ as >mean+5

Using from standard run ‘hot’ is usually only warm Definition of hot still under

refinement Define ‘dead’ as< mean-5

Using from standard run

D. Lam, M. Hildreth

Axial Axial Stereo Stereo

Layer Hot Dead Hot Dead

A 44(1.6%) 9(0.4%) 44(1.7%) 8(0.3%)

B 92(2.9%) 7(0.2%) 55(1.7%) 19(0.6%)

C 96(2.5%) 7(0.2%) 60(1.6%) 34(0.9%)

D 100(2.2%) 14(0.3%) 100(2.2%) 80(1.8%)

E 50(1.0%) 43(0.8%) 45(0.9%) 5(0.1%)

F 69(1.2%) 10(0.2%) 60(1.0%) 17(0.3%)

G 72(1.1%) 40(0.6%) 64(1.0%) 18(0.3%)

H 100(1.4%) 13(0.2%) 100(1.4%) 16(0.2%)

All 623(1.6%) 143(0.4%) 528(1.4%) 197(0.5%)

Hot and Dead Channels

Efficiency

Layer efficiencies Build 15 out of 15 layer tracks, ask if 16th

layer is there.

Z->ee tracking efficiency (in ||<0.8) = 46.4%-65.2% (depending on alg.) from

TARC = (64.0 ± 4.7 ± 7.0)% from EMID

yesterday

Z->ee efficiency, from L3 tracking (in ||<1.2)

= 65% If Run>150,000 = 80% If 7 or more hits = 94%

B. Wang, S. Kulik, A. Kharchilava, M. Drazil

R. Zitoun

D. Whiteson

LayerAAUBBVCCUDDVEEUFFVGGU

Efficiency98.880.02%97.700.02%99.130.02%97.160.02%99.140.02%96.690.02%99.170.02%98.180.02%97.060.02%97.910.02%99.620.02%97.690.02%99.220.05%95.970.02%

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Min-Bias Occupancy

Occupancy/layer Zero bias

occupancy Min-bias events Physics trigger

occupancy

1-8 Axial, 9-16 stereo (two conventions)

A. Bellavance

Zero Bias running Physics running

Min-bias events

CPS MIP studies

MIP peak in ADC counts for two gains. As we currently run (in

MIP mode) A small step (x2) towards

shower mode.

A. Askew

EM Identification

pt>15, |ID|< 20, iso<0.15, Emfr >0.9, HMx <100 Rejection

Run>151,831 and 1 of two EM in CPS fiducial.

One of two EM has cps_cal_match_prob>1e-4

Each EM in CPS fiducial has match.

Efficiency Track match Track and CPS match

Rejection 0.8(0.6), Efficiency 0.9

FPS

Fully instrumented for 3 months

P13 now has an FPS cluster chunk, so one can match the FPS to tracks or calorimeter objects in the thumbnail.

Still issues to resolve

A. Patwa, M. Hildreth, Y. Mutaf, A. Turcot

Efforts in progress

Trying to monitor tick and turn to insure that there is no event mixing

VRB software (G. Brooijmans, etc) Sequencer software (F. Borcherding, M. Utes, L. Xuan)

Developing Software for Monitoring the data quality. (D. Lam, M. Hildreth, DA)

Improve Operations Minimize Dead time

Eliminate FEB’s Eliminate Missing (incomplete) events Respond to unusual events

Optimize AFE performance (F. Borcherding, J. Warchol) Improve performance (Discriminators/Gain/Bias studies) Hot Regions/ Dead Regions

Hot/Dead Regions

Regions of the detector (multiples of 1024 channels) are on ‘all’ the time, or are off ‘all’ the time. These problems appear without warning Easy to ‘fix’ Used to appear around once a day, they now occur a few

times a shift.

This appears to be related to the Sequencers. This is our highest

Priority issue.

Plans

Resolve Hot/Dead regions Reduce discriminator threshold Efficiency: Attempt to identify problems clustering Automated run quality measurement Improved control room tools and documentation Areas which need attention

Use DB for CFT/PS reconstruction Offline analysis aimed at understanding and improving

detector performance Tuning CFT/PS Significant Event Server alarms. Preparing the CFT/PS for Comics downloads

Conclusions

CFT Over 99% channels operational Layer efficiencies ~99% for axial, ~97% for stereo

CPS Three D cluster to track matching efficiency >90% Beginning implementation for EM identification

FPS Offline reconstruction True studies can now begin

Optimization continues