Transcript R&D at LPHE/EPFL: SiPM and electronics

CHIPP Workshop on Detector R&D
Geneva, 11.-12.June 2008
R&D at LPHE/EPFL: SiPM and DAQ
electronics
Guido Haefeli
Introduction
Aim to maintain and enhance our current expertise
in detector technology for the LHCb experiment:
1) Fast DAQ readout electronics
TELL1 board: common 1 MHz readout board for
LHCb
⇒ increase the readout speed to 40 MHz
enabling fully software trigger scheme
2) Precision tracking system
LHCb Inner Tracker: silicon micro-strip detector near
beam pipe
⇒ move to scintillating fibre with SiPM readout
enabling large surface precision tracking
Current TELL1
 Digitization (VELO)
 Synchronization (TTC)
 Data compression (factor 10)
 Buffering
 Ethernet and IP formatting (framer), physical IF
24 x 1.28 Gbit/s
= 30 Gbit/s
GOL TLK2501
@1.6Gbit/s
4 x 1 Gbit/s
= 4 Gbit/s
Gigabit Ethernet
with IP
~300 board to read
out almost all subdetectors in LHCb
Vertex Locator
Analogue links, use
digitizer mezzanine cards
Instead of optical receivers.
All other sub-detectors use optical links
Requirements for LHCb upgrade
 40 times more data in SLHCb, needs many high speed serial links to cope
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with the necessary data bandwidth, for example 300 Gbit/s input and 40
Gbit/s output bandwidth is required (TELL1 x 10 in bandwidth).
Make use of the future Gigabit Bidirectional Trigger and Data link (GBT)
developed by Cern as interconnect between the FE and the DAQ.
Minimize power consumption as it becomes critical with the dense
integration of serial links, FPGA data processing and memory.
Minimize event building overhead in receiving PC by adaptation of network
protocol (for example use Infiniband with RDMA)
Avoid event based network traffic (all sources send to one destination at the
same time)! Sufficient buffering is needed.
Improve data reduction algorithm in terms of performance but also
implementation of simulation (authomatic c-model generation) .
First level trigger information extraction possibility for intelligent event
selection.
LHCb upgrade FE and DAQ
R&D plan for a new DAQ board
 Study the implementation of the dense high speed
interconnection part of the design and optimize for power
consumption and signal integrity.
 Acquire and extend knowledge of the implementation of
zero-suppression algorithms using FPGAs and higher level
hardware description languages (SystemC, CatapultC…).
Simulation support for algorithm selection.
 Evaluate the performance of different network protocols and
link technologies. Build 4 x10 Gigabit Ethernet and 40
Gigabit Infiniband prototype demonstrator board.
Scintillating fibres read with SiPM
 Scintillating fibres can be used not only for Calorimeters but also for precision
trackers with small 250 µm thick fibres.
 SiPM can be used as a very compact photon detector
⇒need multi-channel SiPM:
Our Main Interest
Collaboration with Hamamatsu commercially available single channel SiPM
and prototype multi-channel SiPMT developed for us.
One readout channel for
20x4 pixels, 32 channels
R&D plan and possible application
R&D plan:
 Study in detail properties of Hamamatsu multi-channel SiPM and
optimize the geometry
 Study optical coupling between fibres and SiPM
 Test fibre tracker prototypes i.e. fibres and SiPM from different
vendors (collaboration with Aachen)
Application:
 Near future, < 5 years
Readout of EM calorimeter for a balloon experiment
(PEBs: measurement of e+ spectrum)
 Medium future, <10 years
Unified Tracker System for SuperLHCb