Guido Haefeli

CHIPP Workshop on Detector R&D Geneva, 11.-12.June 2008

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

IntroductionAim to maintain and enhance our current expertise in detector technology for the LHCb experiment:

1) Fast DAQ readout electronicsTELL1 board: common 1 MHz readout board for LHCb⇒ increase the readout speed to 40 MHzenabling fully software trigger scheme

2) Precision tracking systemLHCb Inner Tracker: silicon micro-strip detector near beam pipe⇒ move to scintillating fibre with SiPM readoutenabling large surface precision tracking

Current TELL1Digitization (VELO)Synchronization (TTC)Data compression (factor 10)BufferingEthernet 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

Data compression

~10

Vertex LocatorAnalogue links, use digitizer mezzanine cardsInstead of optical receivers.

~300 board to read out almost all sub-detectors in LHCb

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 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 boardStudy 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 InterestCollaboration 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 applicationR&D plan:Study in detail properties of Hamamatsu multi-channel SiPM and optimize the geometry

Study optical coupling between fibres and SiPMTest 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