1 (Gerard Visser – STAR Integration Meeting 5/16/2008)

STAR Forward GEM Tracker Readout/DAQ Integration

G. Visser

Indiana University Cyclotron Facility

5/16/2008

2 (Gerard Visser – STAR Integration Meeting 5/16/2008)

Modular readout crate architectureModular readout crate architecture

backplane

AR

C

AR

M

AR

M

AR

M

AR

M

AR

M

AR

M

Optical fiber to D-RORC

7 pair cable or optical fiber from STAR TCD

ALICE SIU (mezzanine board)

Signal & Power cables, ≈ 8.3 m, to APV Connector/Motherboards

Remote regulated DC power

• Two crates, each handles 12 cables, 10 APV’s per cable, a total of 15360 detector channels per crate

• ARM (APV Readout Module): 20 ADC channels and data processing FPGA’s (zero suppression, pileup rejection); power for APV on ARM or separate new board (4/crate)

• ARC (APV Readout Controller): control FPGA’s, STAR clock/trigger interface and ALICE SIU (data/control link)

• Connected by passive backplane, 30 MHz synchronous 24 bit datapath

• Uses commercial hardware (6U crate, VME P1 backplane)

• Crates mounted on west end ring of STAR magnet, e.g., in former location of SVT crate; magnetic field tolerant design

3 (Gerard Visser – STAR Integration Meeting 5/16/2008)

FGT DC Power and GroundingFGT DC Power and Grounding

read

out c

rate

ba

ckpl

ane

Isolated dual DC supply (Wiener PL-508)

4x 4AWG

sense lines 4C 18AWG

+6 V @ 36 A, -6 V @ 22 A

Quasi-isolated output +/-1.8V regulator

Low-dropout low noise regulator +/-1.25V

3x 20AWG APV25 ASIC’s

20AWG

FEE GND OPTION JUMPER

+1.8 V @ 0.90 A, -1.8 V @ 1.56 A

STAR GND (magnet steel)

GEM bias divider / bypass caps

STAR GND (TPC structure)

Non-isolated HV DC supply

PREFERRED FEE GND OPTION

ARM (only 1 shown here)APV Motherboard assy. (1 of 24 shown here)

8.3 m

24 m

Local loads, not detailed here

HV coax, shown here as two lines for clarity

south platform 2nd level readout crate (only 1 shown here)

POWER SUMMARY (ENTIRE FGT LV)

240 APV CHIPS 74 W

FEE (MOTHERBOARDS) TOTAL 106 W

READOUT CABLES 25 W

READOUT CRATES 577 W

DC INPUT CABLES 137 W

DC SUPPLY LOSSES 173 W

OVERALL TOTAL 1019 W

Inside, at detector

4 (Gerard Visser – STAR Integration Meeting 5/16/2008)

(Stock) Cables from ARM to ACB/AMB(Stock) Cables from ARM to ACB/AMB• Power & ground, 7C #20 AWG – Belden #5405FE, 5.1mm dia., 56.7 g/m

• +1.8 V force

• +1.8 V sense

• power return “ground” force

• ground sense

• -1.8 V force

• -1.8 V sense

• detector ground connection

• foil shield w/ #22 AWG drain wire

• Control & signal, 18Pair (3 unused) #28 AWG – Alpha #6398 or Belden #9819, 9.8mm dia., estimated 112 g/m

• CLK to ACB/AMB

• CLK loopback from ACB (arrives at ADC automatically in time w/ signals)

• TRG

• APV signals to RDO (10 pairs)

• I2C SDA/GND

• I2C SCLK/GND

• foil shield w/ #28 AWG drain wire, and tinned copper braid (rather not have it)

• Total cross-section passing last FGT disk: 19.2 cm2 (20 power & 20 signal cables), total mass about 5.5 kg

5 (Gerard Visser – STAR Integration Meeting 5/16/2008)

APV analog output driving a long cableAPV analog output driving a long cable

Noise level <0.7 mV RMS, i.e., >11.5 bit dynamic range

1 1 1 0 1 0 1 0 1 0 0 1

With equalization, full swing is restored, sample-sample crosstalk almost completely cancelled, within 1 sample time (56 ns)

Remaining <1% sample-sample crosstalk may be robustly removed with FIR digital filter

APV ONLY – NO CABLE – 110 Ω LOAD 19 m PVC CABLE IN/OUT (DOUBLE TERMINATED, AD8129 RECV.)

In contrast to CMS, we will send the APV analog signals a considerable distance (8.3 m) from the detector, with no buffering or optical conversion at the detector.

CABLE OUT (DOUBLE TERMINATED, AD8129 RECV., EQ.)The APV “digital” header provides a convenient test pattern

Works fine, even in this test w/ more than double the planned length (ok we could even consider to allow longer cable if we must… I’d like to know this soon!)