High-resolution, fast and radiation-hard silicon tracking station CBM collaboration meeting March 2005 STS working group

Status STS Conceptual design (CDR) First round of simulations (TSR) ITS with 3 pixel planes SIT with 4 equidistant planes, strip technology through out Design iteration (partly in TSR) Optimize configuration Include HitProducers in simulation Physics performance studies for different physics cases Final design (TDP 2006?!) Senors/FE chip, module, support+cooling, readout Technological feasibility (R&D) Full performance simulation To do

Facts after 2 nd round of simulations Beam pipe of 1 cm Ø Fluence above Pixel Strip Depends strongly on the physics case. Alternative configurations for different observables possible. Only strip sensors for stations 4 to 7 (SIT) if micro 2 strips are used close to the beam! First 3 stations (ITS) inside the vacuum! Possibly shielded against good beam vacuum by a foil. Is this the last word

Challenging tasks of the tracking station (I) Micro vertex reconstruction (main task of the ITS) Secondary vertex reconstruction better 50  m (z-coordinate) Extremely high track density Both high resolution and a respectively low material budget are needed. D0→KD0→K

D 0 →K -  + Material budget / plane I. Vassiliev

Challenging tasks of the tracking station (II) Background rejection in low mass dielectron spectroscopy Reconstruction of "incomplete" tracks Needs probably much more redundancy If these are not reconstructed.... those will form a fake open pair

 -electrons are a huge concern Yield in 1 st station: 5/gold ion passing the (1%) target  5000 at frame rates of 10  s and 10 9 ions/s !? P. Koczon

Possible configuration (B-TeV inspired) Outer section of plane 3 outside the vacuum! Highest granularity not needed there Allows using thin vacuum window Detectors can be moved in two halfs. Remove sensors from beam area during focusing Only two different module geometries Optional for MAPS or Hybrids

Generic designs for simulation Hybrid-like Material budget Resolution MAPS-like Radiation hardness Read-out speed

MAPS material budget a first assessment by Michael Deveaux Stacking of sensors due to inactive read-out area Design VELO (LHCb) inspired 0.29 %

MAPS R&D Dense program of chip submission in 2005 MIMOSA 9 →factor 2 lower signal than expected MIMOSA 10 → MIMOSTAR1 first prototype for STAR IT MIMOSA 11 →Various sensor geometries for studying aspects of radiation tolerance MIMOSA 12 →Multiple charge storage on-pixel, aspects of capacitor performance MIMOSA 13 →Current readout faster, better noise immunity Transfer of one test station to Frankfurt Support R&D efforts starting with MIMOSA11 Aspects of cryogenic operation

Assessment for GIGATRACKER NA48: CERN-SPSC (K + →   ) Concept (only small area needs to be covered) High rate: 40 MHz / cm ps time resolution Fluence cm 2 (12 Mrad) 0.13  m envisaged x/X 0 < 0.6%

STS working packages STS ITS MAPS R&D Module design Hybrid R&D Module design SIT Sensor design FEE R&D Module design Overall configuration Readout interface Integration & Infrastructure

Design optimization Design Optimization Mainframe AlgorithmsDigitizers Final configuration Tracking groups STS group MAPS HitProducer (Michael) Strip HitProducer (Valeri) Physics benchmarks: ûOpen charm i.e D 0 /run ûLow-mass dielectrons S/B < 1/5 ?

Towards a Design Proposal Vertex tracker (ITS)Main tracker (SIT) MAPSfall backStrip Design optimization Granularity Resolution Configuration GSI, IReSGSI, IKFObninsk Choice of technology Sensor Readout Module/plane design IReSMSU/MEPHI R&DIReS, IKFMSU/MEPHI Infrastructure/ Environment Management