# Presentation: 265592

## Status of the Central Fiber Tracker(CFT)Central Preshower(CPS)and Forward Preshower(FPS)or CFT/PS for short

**Drew 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

- 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**

- Seq Firmware to remove ped shift after threshold

- Clockgen for Uniform ped

- First 264 Read attempt

- 264 Read all ticks

- Swapped board... cryo modifications

- March

- October

- 3

- 9

- 58

- 68

- 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

## Hot and Dead Channels

|  | 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 16****th**** 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

## Min-Bias Occupancy

**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**