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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)