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SALTRO16 activities in Lund

Lund Universitypresented 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, September2010: 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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16 ch ALTRO PCA16 Kapton cable

SALTRO16

PAD plane

Front End CardBackplane New design

MCMMulti Chip Module

Pad plane

LVLV

LV LVCONTROL

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•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 analysedand 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.

Protoype planning within AIDA time and resource frame

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-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

Advantages of Multi Chip Module (MCM) compared to all electronics on the padpanel:

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Back plane

FEC-MCM

LV&ctrl

Padpanel

LV VoltageregulatorsFPGA Board CTRL

Horisontal FEC-MCM design

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FEC-MCM8 SALTRO16128 channelsNaked Si wirebonded to boardCard size 31.5*23.5mm Pad pitch 1x5.9 mm possible

Belo

w s

ide

Top

side

4 connectors to pad board

Connectors to LV&CTRL board

Horisontal design

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On a pad panel. 6*6 matrix of FEC-MCM.Total 4608 channels, pad size, 1.0*5.9mm possible

209 mm

170 mm

234 mm

FEC-MCM

Connector

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But in the prototype stage where we are now and a couple of years to comewe 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 SALTROPad pitch 1x4.6 possible

32chMCM

LV&CTRL

Bus card

PAD PLANE

SALTRO16 SALTRO16

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SALTRO16:Evaluation at CERN: 201103-201105

MCM:Specification : 2011/03-2011/06Design: 2011/09-2011/11Fabrication: 2011/12-2012/01Test: 2012/02-2012/04Redesign and fabrication: 2012/05-2012/08Test: 2012/09-2012/10

LV&CTRL/Buscard:Specification : 2011/03-2011/06Design: 2011/07-2011/09Fabrication: 2011/10-2011/11Test with ALTRO+PCA16/SALTRO16: 2011/12-2012/01Redesign and fabrication: 2012/02-2012/05Test: 2012/06-2012/08

Small System test:MSM/LV&CTRL/Buscard:2012/11-2013/02Final fabrication: 2013/03-2013/05Full System test: 2013/06-2013/09

Input protection:Beam test at DESY: 2011/06Evaluation: 2011/07-2011/08

PCMAG:to Japan: 2011/07back: 2012/07