CMS Week Dec 2002 E. Hazen

HF Electronics

Status Report

E. Hazen, J. Rohlf, E. MachadoBoston University

CMS Week Dec 2002 E. Hazen

HF Electronics InstallationPreliminary

J OYCE/ D AYTO N CO RP.

SCREW J ACK

20 TO N CAPACI TY

Fan tray

Heat exchanger

DC Power supply

Cooling air return

Cooling air return

ROB8

QIE

5

ROB

ROB2

QIE

QIE

Rack protection

1

QIE

QIE

QIE

QIE

-ROB-

4

QIE

QIE

QIE

QIE

-ROB-

7

-ROB-

QIE

QIE

QIE

QIE

Cable support

CAL

QIE CCM

2

QIE

QIE

QIE

QIE

3

QIE

QIE

Cable support

QIE CCM

-ROB-ROB

-ROB-5

QIE

QIE

QIE

ROB

QIE

6

QIE

QIE

Cable support

QIE CCM

-ROB-8

ROB9

QIE

QIE

QIE

QIE

QIE

QIE

QIE

ROB2

QIE

Heat exchanger

DC Power supply

Cooling air return

QIE

QIE

QIE

QIE

1

-ROB-

QIE

QIE

QIE

QIE

QIE

QIECCM

QIE

QIE

QIE

QIECAL

QIE

Cable support

Fan tray

Cable support

QIE CCM

-ROB-2

ROB3

QIE

QIE

QIE

QIE

QIE

QIE

Cooling air return

Rack protection

ROB8

5

ROB

QIE

4

-ROB-

7

QIE

QIE

QIE

QIE

-ROB-

Cable support

QIE CCM

-ROB-5

ROB6

8 9

QIE

QIE

QIE

QIE

QIE

QIE

-ROB-ROB

Cable support

Rack protection

Cooling air return

Cable support

Cable support

Cooling air return

DC Power supply

Heat exchanger

Fan tray

-ROB-

-ROB-

-ROB-

QI E

QI E

1

QIE

QI E

4

QIE

QI E

7

CA

L

ROB

QI E

QI E

QI E

2

QIE

ROB

QI E

QI E

QI E

5

QIE

CC

MC

CM

ROB

QI E

QI E

QI E

8

QIE CC

M

QI E

QI E

-ROB-

QI E

QI E

QI E

ROB2

QIE

QI E

3

-ROB-

QI E

QI E

QI E

ROB5

QIE

QIE

6

QIE

-ROB-

QI E

QI E

QI E

ROB8

QIE

QIE

9

HF Readout Boxes24 PMTs each

Cable Route ~5mthrough shielding

Electronics Housedin standard racks(3U card cages)

CMS Week Dec 2002 E. Hazen

HF QIE Crate Proposal

QIE

QIE

QIE

QIE

QIE

QIECC

M

QIE

QIE

QIE

QIE

QIE

QIE

Cable support

8

ROB-ROB-7 9

-ROB-ROB8

QIE Board6 Channels

4 Boards= 1 PMT box Clock and

Control Module(3 boards)

Standard 3Usubrack(custom backplane)

ROB 1 ROB 2 ROB 3 ROB 4CCM

Typically only 3 of 4ROBs used

Calibration module can occupyunused ROB site (up to 5 slots - 10cm)

CMS Week Dec 2002 E. Hazen

PMT Base PCB

Base Supports8 PMTs withHV distribution

Rear detail showing dual coax(signal plus reference)for each PMT

This is fine for current testing butshould probably change to a soldertermination for production.

CMS Week Dec 2002 E. Hazen

HF PMT Cabling

Octal PMT Boards

16 (short) coaxor other option?

12-pair Skew-Clear

6-channel QIE Boards

PatchPanel

Readout Box (24 PMTs)

CMS Week Dec 2002 E. Hazen

PMT to QIE connectionPreliminary

PMT Anode

93Ω coax 100Ω pair

(or multi-coax)

Coax shield groundat each PMT base

Overall shield connectedto QIE ground

Separate Ground foreach PMT

QIE SignalInput

QIE ReferenceInput

PMT Box

Two pairs perPMT channel

Multi-pin shieldedconnectors

CMS Week Dec 2002 E. Hazen

PMT Box Patch Panel

MDR-36 Connector Site

Mini-coaxcompatiblewith existingPMT boards

We plan to make a smallPCB which connects 6 PMTsto one multi-pin connector.

These can be retro-fitted toexisting PMT boxes for thetest beam.

The final box could use a similarPCB or a larger one which wouldhandle 24 PMTs.

CMS Week Dec 2002 E. Hazen

HF QIE Digitizer Board

Change to 36 pin MDR Connector(12 pairs, each with GND)

Optical Outputs changeto Honeywell ST connectorVCSEL (but still near rear)

Electrically identical to HCAL version3U Eurocard form factor

CMS Week Dec 2002 E. Hazen

Amphenol Skew-ClearTM Cable

● High-performance, compact● Available in zero-halogen

version (ATLAS, CMS)● Terminates to convenient

Mini-D connectors withoverall metal shell

CMS Week Dec 2002 E. Hazen

Skew-Clear Cable Drawing

Will supply zero-halogen version on request

OD = 10mm (28AWG) or 12mm (24AWG)

CMS Week Dec 2002 E. Hazen

MDR Connector Proposed Pinout

Ref Signal

Ref Return Signal Return

Shield

Shield

12-pair Skew-Clear cable handles 6 QIE channelsEach channel has:

Pair 1: Signal, Signal Return, ShieldPair 2: Reference, Reference Return, Shield

Overall Shield connected to metal connector backshell

CMS Week Dec 2002 E. Hazen

PMT + Cable + QIEPedestal (noise) measurement

HV=1100 V

50 Ω rms = 0.74

100 Ω rms = 0.53

As expected, 100 ohm cableimproves noise by sqrt(2)

CMS Week Dec 2002 E. Hazen

Coax Cable Noise vs Length

0 1 2 3 4 5 60.4

0.4250.45

0.4750.5

0.5250.55

0.5750.6

0.6250.65

0.6750.7

0.7250.75

0.7750.8

RG-174 Coax

Noise

Length(m)

QIE

ra

w (

rms)

CMS Week Dec 2002 E. Hazen

Skew-Clear Cable Noise vs Length

0 1 2 3 4 5 60.35

0.375

0.4

0.425

0.45

0.475

0.5

0.525

0.55

0.575

Skew-Clear 8 pair 24AWG

Noise

Length (m)

QIE

raw

(rm

s)

Scatter due toinconsistent results(probably a badconnection)

CMS Week Dec 2002 E. Hazen

HF Noise Test Summary

● PMT Test setup comissioned with QIE/HTR/DCC chain.

● Extensive testing done with two cable types, lengths from 1-6m:– Dual RG-174 coax with overall braid shield– Amphenol Skew-Clear(tm) 100Ω shielded pair

● Noise performance is excellent:– 9500e rms (1.5fC) for 6m skew-clear cable– 12500e rms (2.0fC) for 6m RG-174 coax cable

(single pe is 8fC for PMT gain of 5E4)

CMS Week Dec 2002 E. Hazen

QIE Response to Pulser

4m RG-174

1m RG-174

CMS Week Dec 2002 E. Hazen

PMT Pulse Examples

fC

~ 125 pe

PMT pulsed usingNichia blue LEDand avalanche pulser

Coupled through 2mRG-174 coax

QIE Samples (30ns each)

~ 35 pe

CMS Week Dec 2002 E. Hazen

Cable Matching Issues

● Problems with impedance matching:– RG-174 coax okay, but overall braid lowers

impedance --> reflections– Paired cable (like skew-clear) is 100 ohm differential impedance only... single-ended impedance to ground is lower... not well matched to high-impedance setting of QIE.

● 93 ohm ribbon coax may be the best choice

CMS Week Dec 2002 E. Hazen

HF Front-End Status Summary

Item Responsible Status To Do

PMT Base Fermilab Prototyped Update design for paired cableReview grounding, test crosstalk

PMT Box Fermilab / TTU Prototyped Design patch panel, test EMC+Iowa State and crosstalk

Cable Boston Univ. Selection Prototype multi-channel cable(s)evaluate coax vs pair; choose type

QIE Board Fermilab Prototypedmulti-channel connector

QIE Crate B.U. / Fermilab Prototyped Settle slot layoutFinalize backplane design

LV Power Fermilab conceptual Prototype rad-tol designdesign test and evaluate

Build 2nd prototype with

CMS Week Dec 2002 E. Hazen

Critical Issues for FE● Cable / Connector:

– Pair vs coax issue still open: must settle ASAP so new QIE prototype can proceed. Need proper PCBs to make meaningful measurements of dispersion, crosstalk.

– ROBOX design follows: PMT board, patch panel.● Crate issues:

– Backplane design

– Power & Cooling● LVPS

– How best to utilize 'common LV' schemewithout compromising performance

CMS Week Dec 2002 E. Hazen

Web Page for HF Front-Endhttp://ohm.bu.edu/~emachado/HF

New web pagewith cable/connectordocumentation.

Will be expandedas more documentsbecome available...

CMS Week Dec 2002 E. Hazen

HF Electronics Meeting Proposal

● Start with video conferences● Follow up with 'workshop' style meeting at

Boston or Fermilab (late Jan or early Feb)