Leo Greiner 2007-09-11 TC_Int 1

Sensor and Readout Status of the PIXEL Detector

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Talk Structure

• Sensors

• Readout

• Development and Prototyping with test results

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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)

SensorPixels

AnalogSignals ADC /

Disc.CDS

DataSparsification

RDOto

DAQ

Mimostar sensors

Phase-1sensors - 640 us integration time

Ultimate sensors - < 200 us integration time

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HFT PIXEL Readout Functional Goals

• Triggered detector system fitting into existing STAR infrastructure (Trigger, DAQ, etc.)

• Deliver full frame events to STAR DAQ for event building at approximately the same rate as the TPC (1 KHz for DAQ1000).

• Reduce the total data rate of the detector to a manageable level (< TPC rate).

• Reliable, robust, cost effective, etc.

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Mimostar Data Flow

MIMOSTAR

HFT Ladder

I => V conversionand drivers

20 x 50 MHz Analog signalsclock, control, JTAG, power,ground.

10 MIMOSTAR Detectors

cableto motherboard

HFT Motherboard

Daughter Card (x3)

ADCCDS

(FPGA)

RAM

analog data

clock, control, JTAG, power,ground.

ToLadder

Hit dataTo DAQ RORC

Control /Trigger(FPGA)

STAR Clock andTrigger Distribution

Control

Hit finddata red.(FPGA)

SIU

Buffer

System Goal:10 Sensors / Ladder33 Ladders135M Pixel

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8-bit post-CDSdata50 MHz datastream.

18pixel addresscounter

Cluster Finding Saving Address Only

Cluster sensor operateson these 9 pixels

Enable

ToEventBuilder

columnn

columnn-1

columnn+1

row nrow n-1 row n+1

highthresh.

shift register length = 1 column

Data examinedPer clock cycleImplemented in FPGA on daughter card

Raster scan

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Cluster Finder Efficiency

Real Data taken with MIMOSTAR2 detectors by IPHC

Traditional ADC Sum Method 2 Threshold FPGA method

Cut on the central pixel goes from 14 to 8 ADC counts (left to right) every 1 ADC. 1 ADC = 7.1 e-.

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PIXEL Data Rates (1 KHz)

• Rate @ R1 (2.5cm) = 52.9 / cm2

• Rate @ R2 (6.5cm) = 10.75 / cm2

• Rate @ R3 (7.5cm) = 8.76 / cm2 (at L = 1027)• Average event size = 114 KB• Data Rate = 114 MB/sec at 1KHz• 33 fibers• 33 RORC (6 readout PCs)

MIMOSTARSensors

50.7 GB/s

ADCsADCs

ADCs

AnalogSignals

CDS

38 GB/sDAQ EVENTBUILDER

114 MB/secHit

Finder+ address

Phase-1Sensors

3.38 GB/sDAQ EVENTBUILDER

57 MB/secHit

Finder+ address

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Prototype 3 Sensor Telescope

We tested the functionality of a prototype MIMOSTAR2 detector at the LBNL ALS and then in the environment at STAR during the last three weeks of the 2006-2007 run at RHIC. Our goal was to gather 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 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.

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Telescope Electronics / RDO

MIMOSTAR

2

MIMOSTAR

2

MIMOSTAR

2

Motherboard

Analog signalsClock & controlJTAGLU prot. Power

Analog signalsClock & controlCluster FIFOHot Pixel MapMemory Access(for full frame)Trigger infoPower

Stratix

Daughtercard

Trigger, Clockfrom MWPC

Powerfrom MWPC

JTAGx3 for MIMOSTARx1 for daughtercard

Latch upmonitor and reset

powerDDL to Linux PC

serial / ip connection

JTAG

Trigger, ClockCluster FIFOBusy to trigger

PC(WIN)

control conectionto PC in DAQ room

STRATIX

DAUGHTER CARD

RORC SIU

MimoStar2 chips on kapton cables

MOTHERBOARD

Acquisition Server (Linux)

Control PC (Win)

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Telescope Sensors and Mechanical Housing

3 MIMOSTAR2 chips mounted as close together as reasonably possible on low mass kapton cables in a telescope configuration.

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Mimostar2 Telescope test at the ALS

1.2 GeV electrons at the ALS Booster Test Facility

ImportantDue to un-terminated DAC pads on the sensor, our noise level was double the value achieved under ideal conditions at IPHC in France.

IPHC =>11-15 electrons at 30º C LBL => 30-35 electrons at 28º C

MPV = 49 (Standard) and 43 (Radtol) ADC counts at ~230 electrons

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Efficiency and Accidental rates for ALS test

Merged cluster data – typically 2-3 hits per cluster. Increased noise in sensors results in reduced performance.

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Telescope Installed at STAR

Magnet Pole Tip

Electronics Box

Beam Pipe

Telescope head – 1.45 m from interaction point just below beam pipe.

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STAR Prototype Run Results

Typical CDS full frame event in one sensor. Clusters are clearly visible above the noise level.

Measured charged particle flux was ~ 3.9 merged clusters per sensor (1.7 µs integration time, L=81026 cm-2s-1 ).Noise level of system in the STAR environment was 7.48 ADC counts, comparable to laboratory and ALS measurements.Prototype system integrated with STAR Trigger, slow control and run control sub-systems. Events delivered to DAQ standard RDO PC.TLD measured dose at head position, 325 rad over running time. This scales to an integrated dose of several hundred Krad / run.

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Distribution of track angles in Mimostar2 telescope

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Summary for beam runs

• RDO system with data sparsification implemented and functional for Mimostar2 sensors.

• Prototype system characterized, but with increased noise.

• Fully functioning interfaces between our prototype detector and STAR detector infrastructure.

• Completed measurements of detector environment at STAR including induced electronic noise.

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Some tasks and milestones for the next year

• August 2008 – delivery of Phase-1 sensors from the foundry.

• Develop new generation RDO system based on Virtex-5 FPGA.

• Testing of Mimostar2, Mimostar3 and Mimosa22e sensors.

• Prototype low radiation length cable.

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fin