# Presentation: 787417

## The assembly and testing of the D0 silicon detector 

**      ****Oklahoma University**

**The assembly and testing of the D0 silicon detector **

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Outline:

** ****SMT performance criteria**

** ****physics**
** ****operation conditions**

** ****SMT components**
** ****Testing**

** ****debug&repairs**
** ****burn-in**
** ****laser test**

** ****Production status**

** ****Micro discharge effect**

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Physics performance criteria

** ****Six barrel/disk modules (R****in****=2.7cm, R****out****=10cm, l = 60cm)**
** ****Four layers of double-sided detectors (90****0 ****and 2****0**** stereo)**
******Typical detector resolution: 8-12********m**
** ****Extensive use of double-sided detectors             low mass**

** ****3D track reconstruction capabilities**
** ****Momentum resolution (1GeV): ********p****T****/p****T  ****< 10%**
** ****Impact parameter (********) resolution: 30 ********m**
** ****High acceptance for |********3**
** **

**Luminous region: ********z**** ******** 25cm,  ****************m**

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Physics performance criteria (2)

** ****Uniform momentum and IP resolutions ******** more disks are needed**
** ****Include 4 large-area H-disks**

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Operation conditions

** ****L1 Trigger latency: 3.2********s**
** ****Spacing: 132ns or 396ns**
** ****Small gaps between bunches**

** ****32 cell analog pipeline**
** ****Operate at 132 ns interaction rate**
** ****Programmable test pattern, ADC ramp, pedestal, bandwidth, calibration, polarity**
** ****5mW/channel, S/N = 20**

_**SVX II Chip:**_

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Operation conditions (2)

**SMT information              Levels 2 and 3 trigger decisions**

_**Silicon data flow**_

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## SMT Components

_**Barrels:**_

** ****3-chip single-sided, 50********m, needed: 72**
** ****6-chip double-sided, 90****0**** stereo, 50********m (p), 156********m(n),               needed: 144**
** ****9-chip double-sided, 2****0 ****stereo,         50********m (p), 62.5********m (n)             needed: 216**

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## SMT Components(2)

** ****double sided wedges**
** ****50********m(p) and 62.5********m(n) pitch**
** ********15****0**** strips**
** ****needed: 144**

_**	**__**F-disk detectors:**_

** ****single sided wedges**
** ****80********m pitch**
** ********7.5****0**** strips for each pair of half-wedges**
** ****needed: 96**

_**H-disk detectors:**_

**H-wedge**

**F-disk**

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## SMT Components(3)

_**Mechanical accuracy:**_

** ****ladders: 2-5********m**
** ****wedges: 5-10 ********m**

**Measured with OGP machines**

**Detectors:**

**Assembled detectors:**

** ****barrels: 5-10 ********m**
** ****disks: 10-20 ********m**

**Measured with touch probe CMM**

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Tracker fabrication

**Debug&Repairs**

**Burn-in**

**Laser test**

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Debug&Repairs

** ****Test n-side: increase positive bias voltage up to V****d**** + 30**
** ****Test p-side: increase negative bias voltage up to breakdown**
** ****Test the detector with split bias (********V = V****d ****+ 30)**** **

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Debug&Repairs (2)

**Stand alone**

**Interface**

**Detector**

**Bit3**

_**Test stands:**_

**2    Debug**
**1    Repair**
**2    Laser test**
**1    Barrel assembly**
**2    Disk assembly**
**2    Burn-in (larger system)**
**4    At Universities**

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Debug&Repairs (3)

**V****-max****  ****        p-side breakdown voltage**** **

** ****Pull bonds (broken AC capacitors)**
** ****Record ****I(V=V****d ****+ 20)**** ****in positive bias**
** ****V****-max****  ****determined by ****micro-discharge**** **** effect **

_**Debug:**_

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Debug&Repairs (4)

**< I(V = V****d**** + 20) > = 11.3********A (high depl.)**
**< I(V = V****d**** + 20) > = 8.6********A (low depl.)**
**< V****-max  ****> = 21.7 V**

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Debug&Repairs (5)

**Average number of pulled bonds: 0.8%**
_**Broken capacitors:**_
**Voltage**
**0 - 20             89.80%**
**20 - 30             1.50%**
**30 - 40             2.00%**
**40 - 50             1.70%**
**50 - 60             3.20%**
**60 +                 1.80%**

_**Other problems**_**:**
** ****Bad chips**
** ****Touching/missing bonds**
** ****Bad ground**
** ****Shorts&opens**
** ****...**

_**Tools**_**: probe-stand + logic analyzer**

**Yield: ******** 85%**

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Burn-in

_**Goal:**_** test the readout for a longer time (72 hours)**

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Laser test

** ****Scan for dead channels**
** ****Measure depletion voltage and leakage current**

**Laser (1064nm)**

**Ladder**

_**Goal**_**: ****test the sensor**

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Laser test (2)

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Micro-discharge effect

** ****Breakdown occurs at a lower voltage on junction side**
** ****At ****V > V****-max**** I****leak **** and noise increase rapidly**

_**Current bias conditions:**_
**  ****V- = V****-max**** - 5**
**  ****V****+**** = V****oper**** - V-**

**After type inversion: micro discharge will move to n-side**

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Micro-discharge effect (2)

_**Irradiated 90**__**0**__** double sided detector**_**:**
**   **

** ****Fluence:  1.0********10****14**** neutrons/cm****2**
** ****3******** more than RunII**
** ****Type inverted**
** ********discharge moves from p to n side**

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Production status

**Completed assembling:**

** ****4/6 barrels **
** ****8/12 F-disks **
** ****2/4 H-disks **

_**Ready for physics:**_**  March, 2001**

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000

## Slide 22

- D. Mihalcea, Vertex2000

- Sept., 10-15, 2000