Transcript Slide 1

SALTRO16 activities in Lund
Lund University
presented by
Ulf Mjörnmark
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EUDET/LCTPC setup in september 2010
Low voltage Front End Electronics Kapton cables
TPC
Magnet
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ALTRO based Front End Electronics & DAQ
Hardware is based on ALICE TPC readout electronics
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Summary of experiences with the ALTRO
electronics
-Excellent noise, ca 350 electrons on a FEC connected to the chamber
-Operated reliably when taking data in test beams at DESY:
2009: February – March, July, September
2010: September, December
-In September 2010 the system operated with:
7680 channels (60 Front End cards)
3 RCUs, 2 DRORCs
Problems
-Breaking amplifier channels
-Needs compressed air cooling . Not a practical solution for the
future
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Broken channels due to discharges in the GEM system?
Happens too frequently , may in the worst case kill a FEC i.e 128ch.
Has to be solved.
Have emulated with injection of 1mJ in amplifier input.
Kills the internal protection of the channel with same symptoms as real failure.
External diode network as below works as protection for emulated input.
Survives injection of 20mJ.
Will be tested for noise .
Testing on GEM chamber at next DESY test (june 2011).
Evaluate. Final placement?
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Backplane
New design Front End Card
LV
LV
CONTROL
LV
LV
Pad plane
SALTRO16
MCM
Multi Chip Module
16 ch ALTRO PCA16
Kapton cable
PAD plane
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Protoype planning within AIDA time and resource frame
•It has been a working assumption that the final LCTPC will have the readout
electronics mounted directly on the outer face of the pad panel.
•Such a solution has advantages and drawbacks and has to be carefully analysed
and compared to other options.
•For the prototyping with SALTRO16, mounting on the pad panel it is not possible
since the channel density is too low with 16 ch per chip, limiting the pad size
to 1*9mm (Only SALTRO16 on the pad plane, no other circuitry).
•Thus we plan to place the SALTRO16 on a multi-chip-module (MCM) which connects to
the pad panel with the JAE connectors used in the present prototype electronics.
•The so called horisontal mounting as described on the following slides is a viable
option also for the final LC-TPC as it offers many good features compared to direct
mounting on the panel.
•We find that an MCM module with 8 SALTRO16 chips is not a sound starting point
but rather a smaller MCM module should be used.
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Advantages of Multi Chip Module (MCM) compared to all
electronics on the padpanel:
-trace routing from pads to SALTRO16 becomes simpler
- MCM module offers 2 extra layers for components.
- electronics prototyping will be cheaper and easier.
-parallell prototyping possible
-possibility to distribute design and fabrication
-analog and digital functions are well separated,
- minimal heat transport to the TPCendplate
- service by replacement of MCM module.
-simpler endplate construction
-SALTRO16 mounted on padpanel imply 1x9mm pads
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Horisontal FEC-MCM design
FPGA Board CTRL
LV Voltage
regulators
Back plane
LV&ctrl
FEC-MCM
Padpanel
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FEC-MCM
8 SALTRO16
128 channels
Naked Si wirebonded to board
Card size 31.5*23.5mm
Pad pitch 1x5.9 mm possible
Connectors to
LV&CTRL board
Top side
Horisontal design
Below side
4 connectors
to pad board
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On a pad panel.
234 mm
6*6 matrix of FEC-MCM.
Total 4608 channels,
pad size, 1.0*5.9mm possible
170 mm
Connector
FEC-MCM
209 mm
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But in the prototype stage where we are now and a couple of years to come
we think that an FEC-MCM module with 128channels is too risky and expensive
-Risky as long as the broken channel problem is not under control
-Even if we understand this problem, this electronics will be used in tests of
various avalanche chamber prototypes. This is a danger in itself.
Expensive to replace 128 channels if one is broken.
Expensive to manufacture since the chip yield is unknown and the chance of
assembling 8 working but untested chips on a board may be quite low.
The SALTRO16 is a rather large chip. The yield can be as low as 85% (including
bonding). Then only 40% of the modules will be OK if there are 8 SALTRO per
module
As a consequence we think that most prototyping has to be made with a
smaller MCM module.
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VERTICAL 32chMCM with 2 SALTRO
Pad pitch 1x4.6 possible
Bus card
LV&CTRL
32chMCM
SALTRO16
SALTRO16
PAD PLANE
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SALTRO16:
Evaluation at CERN: 201103-201105
MCM:
Specification : 2011/03-2011/06
Design: 2011/09-2011/11
Fabrication: 2011/12-2012/01
Test: 2012/02-2012/04
Redesign and fabrication: 2012/05-2012/08
Test: 2012/09-2012/10
Input protection:
Beam test at DESY: 2011/06
Evaluation: 2011/07-2011/08
PCMAG:
to Japan: 2011/07
back: 2012/07
LV&CTRL/Buscard:
Specification : 2011/03-2011/06
Design: 2011/07-2011/09
Fabrication: 2011/10-2011/11
Test with ALTRO+PCA16/SALTRO16: 2011/12-2012/01
Redesign and fabrication: 2012/02-2012/05
Test: 2012/06-2012/08
Small System test:
MSM/LV&CTRL/Buscard:2012/11-2013/02
Final fabrication: 2013/03-2013/05
Full System test: 2013/06-2013/09
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