# Presentation: 652456

## The STAR Pixel Upgrade

- H. Wieman
- Heavy Quark Workshop
- LBNL
- 1-Nov-2007

## topics

- Pixel silicon
- Readout
- STAR telescope tests
- Mechanical Integration in STAR
- Pixel mechanical

## Some pixel features

| Pointing resolution | (13  12GeV/pc) m |
| --- | --- |
| Layers | Layer 1 at 2.5 cm radius
Layer 2 at 8 cm radius |
| Pixel size | 30 m X 30 m  |
| Hit resolution | 8.7 m |
| Position stability | 10 m |
| Radiation thickness per layer | X/X0 = 0.28% |
| Beam pipe radiation thickness | X/X0 = 0.14% |
| Number of pixels | 164 M |
| Integration time (affects pileup) | 
0.2 ms |
| Rapid installation and replacement | Reproducible positioning |

## Silicon program

- IReS/LEPSI  IPHC (Strasburg)

- _M. Winter_
- C. Hu
- C. Colledani
- W. Dulinski
- A. Himmi
- A. Shabetai
- M. Szelezniak
- I. Valin

## Slide 5

**Notes:**
So, moving on to the sensors. We are using CMOS pixel sensors which are being developed by our collaborators at IRES, now IPHC. There’s a lot of information here but I just want to make a few points about our sensor technology. First is that we are using CMOS technology which is widely available, so we can use any standard CMOS foundry and are not limited to special silicon processes with limited availability. Also, the sensors have full active area, there are no dead areas between the pixels. This type of sensor does not use electron avalanche type gain, the charge is collected and appears as a voltage on the source follower structure. This voltage is buffered, amplified, and read out.

## MIMOSTAR 2/3 technology

- Grzegorz Deptuch

## IPHC Functional Sensor Development

_**Data Processing in RDO and on chip by generation of sensor.**_

- The RDO system design evolves with the sensor generation.

- 30 x 30 μm pixels
- CMOS technology
- Full Reticule = 640 x 640 pixel array

- _Mimostar 2_ => full functionality 1/25 reticule, 1.7 μs integration time (1 frame@50 MHz clk), analog output. *(in hand and tested)*

- _All sensor families:_

- _Phase-1_ and _Ultimate_ sensors => digital output *(in development)*

**Leo Greiner**

**Notes:**
We are following a sensor development programme in collaboration with our colleagues at Strasbourg. There are two series of sensor that we follow with our mechanical and readout development. The first series is the mimostar series which we plan to use to produce a full prototype detector with analog readout. The characteristics are as shown... The ultimate series is the what we intend to use in the final detector. It has mostly the same pixel and physical characteristics as the mimostar series but with much more processing on chip such as on chip CSD, a much shorter 200 us integration time. Programmable dual discriminators and digital output via LVDS

## Phase 1 / Ultimate technology (MIMOSA8/16/22)

- forward
- bias
- diode

- Discriminator

## IHCP  Marc Winter et al

## IHCP  Marc Winter et al

## IHCP  Marc Winter et al

## IHCP  Marc Winter et al

## Silicon summary, development of STAR pixels

- Understand MIMOSTAR 3 yield issues
- Fab Phase 1 based on MIMOSA16/22 technology (digital output,    no zero suppression)
- Fab Ulitimate based on MIMOSA16/22 and SUZE technology (digital with zero suppression)
- Issues
- Dead center MIMOSTAR 3
- Pursue large area gate oxide hypotheses, change layout
- Radiation hardness (bulk damage)
- Reduce temperature
- Investigate silicon improvements

## Readout program

- LBNL

- _Leo Greiner_
- Xiangming Sun
- Michal Szelezniak
- Thorsten Stezelberger
- Chinh Vu
- Howard Matis

## Prototype 3 Sensor Telescope

- Our goal was to test functionality of a prototype MIMOSTAR2 detector in the environment at STAR in the 2006-2007 run at STAR. We obtained information on:
- Charged particle environment near the interaction region in STAR.
- Performance of our cluster finding algorithm.
- Performance of the MIMOSTAR2 sensors.
- Functionality of our tested interfaces to the other STAR subsystems.
- Performance of our hardware / firmware as a system.
- The noise environment in the area in which we expect to put the final PIXEL detector.

**Notes:**
So, we are doing a significant amount of development and prototyping. We are attempting to put together one stream of our final detector. To this end we are using the functionally correct but smaller mimostar2 chips in a telescope configuration and making a detector and associated readout electronics and placement structures. The goals of this effort are shown here.

## Telescope Infrastructure at STAR

- Magnet Pole Tip

- Insertion tube

- Electronics Box

- Beam Pipe

**Notes:**
This assembly is then mounted in STAR. Here we see the pole tip at the end of the solenoid. The beam pipe is here and we have an insertion tube to allow us to push our telescope head close to the interaction point. The cables run along the insertion tube and into the electronics box here. Fiber optic cables carry the data to the STAR DAQ computers. This is all installed at STAR and ready for use. 

## On the fly cluster finding first used with MIMOSTAR analog chips

## Telescope DAQ

## Distribution of track angles in Mimostar2 telescope

- Xiangming Sun
- Michal** **Szelezniak

## RDO Board(s)

- New motherboard

- Two board System – Virtex-5 Development board mated to a new HFT motherboard

- Xilinx Virtex-5 Development Board

- Digital I/O LVDS Drivers
- 4 X >80 MHz ADCs
- PMC connectors for SIU
- Cypress USB chipset
- SODIMM Memory slot
- Serial interface
- Trigger / Control input

- FF1760 Package
- 800 – 1200 I/O pins
- 4.6 – 10.4 Mb block RAM
- 550 MHz internal clock

- Note – This board is designed
- for development and testing.
- Not all features will be loaded
- for production.

- Leo Greiner

## System Design – Physical Layout

- 1 m –
- Low mass twisted pair

- 3 m - twisted pair

- _System Design – Physical Layout_

- Magnet Pole Face
- (Low Rad Area ?)

- DAQ Room

- Power
- Supplies

- Platform

- 30 m

- 100 m - Fiber optic cables

- Leo Greiner

## Data Rates - Parameters

- Rates as per Jim Thomas, L = 3 x 1027 for Phase-1, L = 8 x 1027 for Ultimate.
- 2.5 hits / cluster.
- 1 kHz average event rate.
- 10 inner ladders, 30 outer ladders.
- Factor of 1.6 for event format overhead (can be lowered).
- No run length encoding.

| 61.5 | 6.0 |
| --- | --- |
| 157.0 | 15.0 |

- _R = 2.5_

- _R = 8.0_

- _200 us_

- _640 us_

**Hits / Sensor at L = 8 x 10****27****.**

**Integration**
**Time**

**Radius**

- Leo Greiner

## Data Rates

- Ultimate  => 49.7 MB / s raw addresses.
- 			  => **79.5 MB / s data rate**.
- Phase–1 => 59.6 MB / s raw addresses
- 			  => **95.4 MB / s data rate.**

- The dead-time is primarily limited by the number of externally allocated readout buffers!

- Leo Greiner

## Mechanical Program

- Eric Anderssen, LBNL engineer working on ATLAS pixels is phasing into our pixel program – full time in January 2008 (carbon composite expert)
- Contracted ARES company for analysis on cooling, precision mount design and refinement of ladder stability.
- Phone meetings weekly
- First results –
- we will need a sub ambient cooling system
- simplified precision mount
- First stage report due in January
- Addressing two items:
- Cylinder modifications for integration of GEMS, IST and Pixels
- Pixel mechanical design

## Cut Apart Current Cones August 2009

- Old East Cone and most of Beams to be reused to support New West Cone
- Old West cone refurbished into New East Cone in Berkeley
- Cut Carbon Elliptical Beams avoiding  Al Insert

*Send to Berkeley*

*Keep at Brookhaven*

- Eric Anderssen

## Modified East Cone and Install with New West Cylinder

- View as Temporary Fix—Should be ACAP (as cheap as possible)
- Supports end of New West Cone/FGT
- Replicates Old Beam Pipe Interfaces
- Includes SSD if required
- Only for summer ’09 to ‘10
- Wholly Machined/Bonded Solution
- Tooling to locate Buck Plate while bonding is required...

*Buck Plate aimed for*
*Easy Swap of replacement*

*Some Tooling Required...*

*~1.5m*

- Eric Anderssen

## Goal—Swap-in Replacement and Install pixels – summer 2010

*Should Be*
*Same Length*

*New East Cone with Cylindrical Shell made from Old West Cone*
*Swap in by matching Bolted Interface to New West Cone...*

*Modification*
*Will Take Up*
*Length...*

*Include SSD interface On Shell*

- Eric Anderssen

## Inner Support Cylinder  (ISC)

- ISC fits inside and is supported by the cone

- ISC supports IST on outside

- ISC

- ISC supports pixel and beam pipe inside

## Pixel support structure – changes and progress

**2.5 cm radius**

**8 cm radius**

**Inner layer**
**Outer layer**

**End view**

**ALICE style carbon support beams (green)**

## cable bundle

| connection type | number of pairs | allocated pair diameter |
| --- | --- | --- |
| Analog power | 1 | 6mm |
| Digital power | 1 | 6mm |
| signal  | 40 | .64mm |
| sync | 1 | .64mm |
| clk | 1 | .64mm |
| marker | 1 | .64mm |
| Jtage (5 conductors) | 3 | .64mm |

## Conceptual mechanical design

## Pixel placement concept

- Detector assembly slides in on rails
- Parallelogram hinges support the two detector halves while sliding
- Cam and follower controls the opening of the hinges during insertion and extraction
- Detector support transfers to kinematic dock when positioned at the operating location

**pixel support hinges**

**spring loaded cam followers and linear cam**

**slide rails**

**sliding carriage**

## Hinge analysis

## Slide 34

## Slide 35

## Two sector patch installation – summer 2010

## Final installation, complete cylinders Aug 2011

**End**

## yearly dose numbers

- Au + Au
- RHIC II luminosity: 7X1027 1/(cm2 sec)
- Weeks per year operation: 25
- Fraction of up time: 60%
- radius: 2.5 cm
- pion dose: 73 kRad
- UPC electron dose: 82 kRad
- Total dose: 155 kRad
- TLD measured projection: 300 kRad
- radius: 8 cm
- pion dose: 7 kRad
- UPC electron dose: 2 kRad
- Total dose: 9 kRad
- TLD measured projection: 29 kRad

## Grzegorz Deptuch

## MIMOSA8, Yavuz Degerli et al  IRes/LEPSI  DAPNIA/SEDI 

**MIMOSA8, Yavuz Degerli et al  IRes/LEPSI  DAPNIA/SEDI **