Efforts for weight reduction in Ecal electronics

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Efforts for weight reduction in Ecal electronics

• HV bricks out of the crates
• Cable length reduction
• Block diagram of the Ecal electronics (new
  revision)

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HV BRICK
3
HV BRICK
4
HV brick (1)

• 19/12/2003 meeting in Firenze with G.
  Castellini, G. Ambrosi, CAEN engineers to discuss
  the removal of the bricks from the crate to gain
  some weight in the crate structure.
• This has been discussed at the Ecal meeting on
  jan 8
• The idea would be to try to move the crate and
  the bricks on 2 sides of the oblique beams ( 2
  or 4 of these)
• This imply
• Limited mechanical modifications to the brick
  structure
• Limited (not strictly necessary) modifications to
  the brick control board
• Thermal and stability studies are necessary

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HV brick (2)
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HV brick (3)

• Mechanical
• The brick is self-consistent no crate is
  necessary
• The card-locks have to be removed
• Some simple supports have to be added
• The control board side is not covered so a wall
  is necessary
• Thermal dissipation even a small contact area is
  enough, but would be better to make a full wall
  contact
• Electronics
• The control board uses a VME like connector to be
  inserted in the backplane. 2 possibilities
• Do not solder the connector. Solder some wires to
  the pads. Bring the cable to a connector in the
  backplane
• Modify the board to add some connectors for
  ribbon cable.

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HV brick (4)

• Thermal
• The heat has to go somewhere thermal studies are
  necessaries
• The bricks are heavy finite elements studies are
  probably necessaries

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HV brick (5)

• If we go in this direction we could take the
  occasion to make other weight and reliability
  gains.
• A good minimal solution could be to distribute
  the bricks through the 4 beams in 2-1-2-1
• A non-minimal solution could imply a complete
  redesign of the bricks to become only 4 , each
  with 324/4 81 channels, one for each beam
  (very costly and time consuming)

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HV brick (6) 2-1-2-1

• HV cables length highly reduced (reduced weight)
  
• Still some channels connected to 2 PMs
• 2 cables (and 2 lecroy bus) from one crate are
  needed

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EDR TRIGGER cabling

• We could reduce also the weight of the data
  cables (EDR to EIBs)
• EDR 3 EIBs (2 Trigger 1 non-trigger)
• Some cables are long, due to the trigger (one
  trigger board for x-view and another for y-view)
• If the crates are moved to the oblique beams, the
  cables could be shorter if we drop the request
  of the same cable for data and trigger
• Besides it would be good, for reliability, to
  partition the system in sectors one brick
  connected to 2 EDRs, to one EPSFE, to one S9057
  etc etc

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EDR TRIGGER cabling now
CR
TRIGGER
CR
DATA
Wires from 1 EIB to EDR 52 (2 cables of 26
wires up to 3m)
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EDR TRIGGER cabling (2)
CR
TRIGGER
CR
DATA
Wires from 1 EIB to EDR 43 (much shorter)
Wires from 1 EIB to ETRG 9
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EDR TRIGGER cabling proposal(3)

• Franck Cadoux is performing exact calculations on
  the mock-up to evaluate the gain in weight due
  to this new architecture.
• We are studying new parts for cables and
  connectors
• Previous results were 14.9 KG for HV cables and
  14.9 KG for dataWe will try to give a new
  estimate at the TIM
• Drawbacks for the splitting
  of the cables
• The trigger board schematics (cPCI) have to be
  changed a lot
• The EIB card needs another connector and the
  actual ones have to reduced in the pin number
• The EDR also needs mods (connectors trigger)

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ECAL electronics block diagram ( half)
backplane
Data power 18 cables
E - CRATE
18x
Trigger 12 cables
Low voltage
Low voltage lecroy
S9054
S9053
EPD
S9057
HV 162 cables
S9057
S9057
HV BRICKS
EIB
28 Volts H/C