# Presentation: 180580

## BTeV Pixel Silicon Detector

- _Test beam results 1999-2000_
- J.A. Appel, J.N. Butler, G. Cardoso, H. Cheung, G. Chiodini D.C. Christian, E.E. Gottschalk, B.K. Hall, J. Hoff, P. A. Kasper, R. Kutschke, S.W.Kwan, A. Mekkaoui, R. Yarema, and S. Zimmermann
-  *Fermi National Accelerator Laboratory*
-  C. Newsom - *University of Iowa*
-  A. Colautti, D. Menasce, and S. Sala - *INFN(Milan)*
-  R. Coluccia and M. Di Corato - *Universita’ di Milano*
- M.Artuso and J.C. Wang – *Syracuse University*
**Talk given by G. Chiodini – Fermilab**
**Genova - Pixel 2000 - June 5-9, 2000**

## Overview 

- Test beam setup
- 5 pixel plane tested
- SSD telescope and DAQ
- Test beam results
- Pixel Calibration
- Charge collection
- Charge-sharing
- Spatial resolution
- Four plane pixel telescope
- Conclusions

- G. Chiodini - Fermilab

## Setup 5 pixel planes tested

- FPIX0 64x12cells
- 8 bit external ADC

- FPIX1 160x18cells
- 2 bit internal FADC

- ST1-CiS p-stop
- ST2-CiS p-spray
- Bonded active area 3.2x4.4mm2

- Two ST1-Seiko p-stop
- ST2-Seiko p-spray
- Bonded active area 8x6.8mm2

_**Samples of FPIX0 and FPIX1 readout chips **_
_**bump-bonded to ATLAS sensor prototypes**_

- 50x400 m2 cells

- 30 m pitch indium bumps

- G. Chiodini - Fermilab

## Setup: 5 pixel planes tested

- _Close-up middle station_

- _FPIX0_
- _Inner Board_

- Pixel detector
- Light protected

- Analog Buffer

- 8 bit ADC

- G. Chiodini - Fermilab

## Setup: SSD telescope and DAQ

**VME ****COMPUTER**

**I/O**
**BOARD**

**STAR**

**TFIB**

-  I/O Board
-     - Controls and Initializes      4 Pixel readout chips
-     - GPIB controller: HV,      thresholds, and pulser
-  Automatic pixel calibration

**Magnet**

**DAQ**

**E**
**T**
**H**
**E**
**R**
**N**
**E**
**T**

- Setup: SSD telescope and DAQ

- G. Chiodini - Fermilab

## Results:pixel calibration - pulse generator

- Qth=2500e-
- Qnoise=106e-

- Qnoise,ADC=400e-
- Dynamics MIP

- G. Chiodini - Fermilab

## Results: Pixel calibration - X ray sources

_**Vth0 = Threshold knob**_

- G. Chiodini - Fermilab

## Results: Charge collection

- Single chip Tile 2 CiS p-spray

- Single chip Tile 1 CiS p-stop

- 1MIP=30100e-

- 1MIP=21500e-

- G. Chiodini - Fermilab

## Results: charge-sharing

| Angle
[degs] | CS=1 | CS=2
 | CS=3
 | CS=4
 | CS=5
 | CS6
 |
| --- | --- | --- | --- | --- | --- | --- |
| 0 | .639 | .328 | .017 | .009 | .0034 | .0025 |
| 5 | .433 | .527 | .022 | .010 | .0041 | .0028 |
| 10 | .090 | .846 | .040 | .015 | .0055 | .0029 |
| 15 | - | .635 | .332 | .022 | .0080 | .0034 |
| 20 | - | .209 | .741 | .031 | .0124 | .0060 |
| 30 | - | - | .178 | .769 | .041 | .0115 |

**Q****th****=2500e****-     ****V****bias****=-140V**

- _Track _
- _inclination_

- _Diffusion_

- _Delta rays emission_

- G. Chiodini - Fermilab

## Results: charge-sharingBias voltage

***ST1 CiS FPIX0 detector***

- G. Chiodini - Fermilab

## Results: charge-sharingThreshold

***ST1 CiS FPIX0 detector***

- G. Chiodini - Fermilab

## Results: spatial resolutionGaussian width 

***ST1 CiS FPIX0 detector***

- G. Chiodini - Fermilab

## Results: spatial resolutionComparison between detectors 

- Qth=2500e-
- Qth=2200e-
- Qth=3780e-

- G. Chiodini - Fermilab

## Results: spatial resolutionBias voltage

***ST1 CiS FPIX0 detector***

- G. Chiodini - Fermilab

## Results: spatial resolutionThreshold 

***ST1 CiS FPIX0 detector***

- G. Chiodini - Fermilab

## Results: spatial resolution2D spatial resolution 

***ST1 CiS FPIX0 detector***

**Sigma=**
**4.65********0.10**

**Sigma=**
**12.9********0.26**

- x

- y

- G. Chiodini - Fermilab

## Results: spatial resolutionNon-Gaussian resolution function 

- CS=1 and track angle < 10 degs:
- Square convoluted with a Gaussian

- CS>1 track angle < 10 degs
- and all CS track angle > 10 degs:
- Gaussian + power law

- _Non-Gaussian part:_
- 15% of events: half in the constant
-                    term and half in the tails
-  power law with an exponent 2

- G. Chiodini - Fermilab

## Four plane pixel telescope 

- Interaction vertex in the target

- Interaction vertex in pixel plane

**2.2mm thick **
**diamond target**

- _Thousands_
- _triggered_
- _multiple_
- _interactions_
- _events_

- G. Chiodini - Fermilab

## Conclusions

- The FPIX-type FE performs well as expected and needed
- GREAT data sample to gain operational experience with PSD’s (_**3M useful events**_)
- Primary features of results are clear:
- Very good resolution at all angles
- 3 ADC bits will be enough for BTeV
- Parameterization of the non-Gaussian tails used in L1 trigger MC simulations
- The BTeV multiplicity is easily handled by 50m x 400m pixels

- G. Chiodini - Fermilab