status of trd chamber and readout electronics integration ken oyama and christian lippmann for the...

Status of TRD Chamber and Readout Status of TRD Chamber and Readout Electronics IntegrationElectronics Integration

Ken Oyama and Christian Lippmann

for the TRD Collaboration

Sep. 26, 2005

TRD status meeting in Cheile Grădiştei, Romania

2005/Sep./25 2

ContentsContents

Investigation for reducing noise.

Remove external noise by good groundings and good H.V. connections.

Testing of new type regulators with charge pump.

Using pre-final power bus bar and its load test. Using prototype water cooling pipes and check noise level with it.

2005/Sep./25 3

Situation TodaySituation Today What is different since before?

1. Power bus bar is there.

2. Cooling pipes are there.

3. Better HV connections.

Recently, TRD test beam stack is mainly operated by M.Gutfleisch with the cosmic trigger, stably.

Study for integration and grounding are mainly done for the stand alone chamber (S.A.C.) outside the stack.

DCS (for CLK, Trig, SCSN) independently powered

single MCM instead of T3 ROBs

L1C0 stand alone chamber (S.A.C.)fully covered by the 6 T4 ROBs

test beam stacktest beam stack

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Load Test of the Prototype Power Bus BarLoad Test of the Prototype Power Bus Bar

A prototype power bus bar with 4 pairs of copper plates ( 0.7 mm x 50 mm each) was tested. 40 A current for each pair is given without cooling (total 160 A).

ResultVoltage drop in 60 cm bar at 40 A load current = 16 ± 1 mV 27 mV/m 0.67 mΩ/m.Expected resistance is 0.5 mΩ/m for pure copper at room temperature while our measurement is 34 % larger.Maximum voltage drop in supermodule will be ~200 mV.The bar had no significant heat (~ human skin) except for around the short cut point.

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(1) Before bus bar installation (2) After bus bar installation

pos0 #261.40

pos1 #251.45

pos3 #271.40

pos2 #281.44

pos5 #231.22

pos4 #241.30

pos0 #261.27

pos1 #251.32

pos3 #271.20

pos2 #281.24

pos5 #231.18

pos4 #241.15

memo: excluded dead or disconnected MCM’s for all measurements.

average1.37

average1.23

( 10 % better )

(3) If we exchange pos 1 and 5 ROB’s

pos0 #261.32

pos1 #231.19

pos3 #271.17

pos2 #281.26

pos5 #251.35

pos4 #241.13

Noise MeasurementNoise Measurement

Noise looks associated to robtype and regulator type.

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T4#0025 with new regulator T4#0023 with old regulator

Noise MeasurementNoise Measurementn

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AC component on 5 V pumped lineon patchworks without capacitors

With two 470 uF capacitorson 5 V pumped line

5V charge pump output (AC cpl.)

PASA output

Noise from Charge PumpNoise from Charge Pump

40 mV

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Two 470 uF for pos5:

pos0 #261.26

pos1 #231.17

pos3 #271.18

pos2 #281.21

pos5 #251.27

pos4 #241.12

Noise Level with Capacitances on Pumped LinesNoise Level with Capacitances on Pumped Lines

Capacitors help but not yet perfect. Turning off of pos3 and pos2 did not help. Extra shielding and battery driving of

charge pump did not help. Increasing connections among ROB’s help

a bit but not yet perfect. Connecting HV GND of filter box to carbon

surface did not help.

2005/Sep./25 9

HV Improving #

pos0 #261.16

pos1 #231.10

pos3 #27OFF

pos2 #28OFF

pos5 #251.06

pos4 #241.04

# direct connection of HV GNDto pos4 ROB GND and better handling of cables.

Improving H.V. ConnectionsImproving H.V. Connections

1. It was found that noise is significantly reduced (> 60 e) if we connect H.V.GND of H.V. filter box to PASA GND on nearest ROB (number above).

2. C.Lippmann found that pos0 noise significantly increased at some point (> to 1.3 LSB). This gave us a hint that handling of H.V. connection from filter box to ROB is really important.

2005/Sep./25 10

pos0 #261.04

pos1 #231.03

pos3 #xxOFF

pos2 #28OFF

pos5 #251.05

pos4 #241.03

Last steps were:

All HV cables from filter box to anode segments were cut to appropriate length (25 cm for row0 and 1). And well gathered and taped so that loop area is minimized.

Red (final) HV cables from HV distribution box to filter box with length similar to that in the super-module, SHV connectors of filter box replaced by soldering. This gives little bit less noise but not significant.

With these connections, noise level does not increase significantly even if you switch back to using charge pump (less than 20 e contribution).

No additional shielding by aluminum foils around chamber is necessary.

The Best Situation Till NowThe Best Situation Till Now

average: 1.038

2005/Sep./25 11

Pos0 ResultsPos0 Results

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2005/Sep./25 13

Although small excess is at 8 o’clock Sep.12,noise level is very stable in ±10 electrons.

Long Term Stability of Noise LevelLong Term Stability of Noise Level

2005/Sep./25 14

Result Average RMS for MCMs under the pipes• without pipe : 1.08 LSB (1.08 for

Pos1)• no grounding of pipe : 1.09 LSB (1.08 for

Pos1)• grounding to L-profile : 1.10 LSB (1.09 for

Pos1)• grounding to PASA GND : 1.08 LSB (1.08 for Pos1)

Conclusion• No significant effect due to pipes but grounding to

PASA GND looks the best. Probably It is safer to have this option.

Testing with Water Cooling Pipe Made by A. MarinTesting with Water Cooling Pipe Made by A. Marin

Cooling water pipes & plates on only MCM0-7

on Position 0 ROB

Grounding by copper strip to ROB

PASA GND

2005/Sep./25 15

ADC-PASA noise measurements(2)ADC-PASA noise measurements(2)

David Muthers, Kaiserslautern

http://www-alice.gsi.de/trd/meetings/status/050425/venelin_20050425.ppt

2005/Sep./25 16

PAD Capacitance Measurement by D.EmschermannPAD Capacitance Measurement by D.Emschermann

L1C1

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without padconnections

(0.64 in avg.)

Pad C are from D.Emschermann’s measurements on L1C1 chamber, and scaled for L1C0 chamber using difference of PAD sizes (80 / 75 and 90 / 75 for row 0 and 1, respectively). In addition, 3.5 pF due to connectors, balls, and traces on ROB and MCM is added. Measurement from D.Muthers and I.Rusanov were multiplied by 1000/1200 because ADC range setup is different between their measurement and our S.A.C.

measurement on L1C0S.A.C (1.04 in avg.)

Note: Fit result for ROB on Chamber thru ADC is: 0.020 * C + 0.577 LSB’s. Line width show 2 sigma deviation.Chi2 / NDF= 2.2 / 473.

Pad Capacitance DependencePad Capacitance Dependence

2005/Sep./25 18

ConclusionsConclusions

Noise level is significantly improved from ~1.37 LSB (1560 e) to ~1.04 LSB (1250 e).

Finalizing grounding method and H.V. connections were almost done but still maybe we can improve (900 e nolse contribution might be still there).

We can investigate whether the noise level stays like now in LSB if we vary gain setup of ADC, and check what is the dominant source is 900 e noise.

Testing of power bus bar was done.

Basic test of water pipe was done and there was no significant effect in noise level.

2005/Sep./25 19

Backup SlidesBackup Slides

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2005/Sep./25 23

Current per bus bar:

Digital 3.3V 　 8 A + ~5 A TRAP + OASE Digital 1.8V 35 A ADC Analog 　 1.8V 38 A ADC Analog 　 3.3V 29 A PASA

Digital and Analog should not be mixed:

Digital 48 A Analog 67 A

* Analog should be closer to the cooling water pipe* PASA can not be touched to digital

so …

Digital 3.3V ~13 ADigital 1.8V 35 AAnalog 　 1.8V 38 AAnalog 　 3.3V 29 Acooling

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2005/Sep./25 25

Noise Measurements 2Noise Measurements 2

strong effect of badly routed pre-trigger line.

But most of them have no problem.

2005/Sep./25 26

No Correlation between with and w.o. PADsNo Correlation between with and w.o. PADs

2005/Sep./25 27

status of trd chamber and readout electronics integration ken oyama and christian lippmann for the...

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