summary sts working group design optimization sts (strip) layout r&d (maps) working packages
TRANSCRIPT
Summary STS working group
Design optimizationSTS (Strip) layout
R&D (MAPS)Working packages
Manpower
! STS activities momentarily not backed by EU funding
FP6 I3 (SOSDET) R&D on monolithic (MAPS, amorphous Si) and
ultra-thin hybrid (Giga-tracker) sensors. not funded in favor of diamond → standard technologically!!
FP6 Design close call STS foreseen for second round (i.e. 2005) now cancelled in favor of proposals from first round
Total manpower in STS project of O(1 FTE)
Generic simulation
Design as of now: 7 stations at 5,10,20,40,60,80,100 cm from target 100 mm (1,2) and 200 mm (3-7) thick 10, 20 m resolution in both coordinates
Needed for proposal Simulation including pad, strip structure Optimized configuration
Design optimization
Design Optimization
Mainframe
Algorithms Digitizers
Final configuration
Tracking groups
STS group
MAPS:Michaels talk
Strip:Tatianas talk
Valery
Si strip STS_4 Layout Si strip STS_4 Layout
Basic Elements: Inner : 6x2 cm Middle : 6x4 cmOuter : 6X12 cm
-20 cm
+20 cm
Read out
Valery Savielev,Obninsk State Univ.
Si strip STS_6 Layout Si strip STS_6 Layout
Basic Elements: Inner : 6x4 cm Middle : 6x12 cmOuter : 6X20 cm
+40 cm
-40 cm
Read out
+4cm
- 4cm
Valery Savielev,Obninsk State Univ.
Digitization result
number of zone
num
ber
of h
its
3-d STS 4-th STS 5-th STS
6-th STS 7-th STS
T.Galatyuk October 6-8 2004 CBM collaboration meeting 9
MC hits (points)
reconstructed hits
Tatiana Galatyuk,GSI/Kiev
R&D
MAPS; IReS, LEPSI, (GSI) radiation tolerance readout speed
Driven by common interest between NLC and CBM community
Strip detectors; MEPHI, MSU Thin double-sided sensors Read-out (FEE) chip
no activity yet due to missing funding
100 200 300 400
1000
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5000
6000
100 200 300 400
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1000
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Successor1 before and after 1MRad X-Rays
Observations (Priliminary):
No significant influence on gain
Charge collected in 1 pixel [ADC]
Charge collected in 9 pixels [ADC]
T = -15°C t = ~ 200µs
No significant charge loss
CBM collaboration meeting, GSI Darmstadt, 6-8 Oct 2004, Michael Deveaux ([email protected])
Michael Deveaux, GSI/IReS
• Control and address Electronics
• Fast signal processing and data sparsification Signal digitalisation
• Storage threshold values needed during data sparsification
• Surface ratio (B2/B1) must be as small as possible
Matrix of Pixel
Control ELN
Sparcification
Memori-sation
Smart Detector Reticle
Band Height of non-sensitive part B2
Sensitive part
Control and processing partADC
Band Height of sensitive part
B1
Hayet Kebbati,GSI/IReS
Towards a Design Proposal
Vertex tracker Main tracker
MAPS fall back Strip
Design optimization Granularity Resolution Configuration
GSI Obninsk
Choice of technology Sensor Readout
IReS MSU/MEPHI
R&D IReS MSU/MEPHI
Infrastructure/Environment
Management
The end ...
Choice of technology
Availability Minimize own development effort (manpower)
LHC silicon trackers needed 800 man years R&D Conservative fall-back solutions for future technology
options
Problems / Open questions Material budget increase to balance position resolution! identification of conversion electrons
Efficiency?
Realistic simulation for track fragment reconstruction Efficiency Fake rate
Magnetic field Close pair recognition in the inner tracking section
Efficiency? -electrons
Vertex reconstruction fast station needed in vacuum?
Oleg Rogachevski, conformal mapping
5,10,20,40,60,80,100 cm, 3 first stations in vacuum, 100 mm (1-2) and 200 mm (3-7) thickness.
no delta electrons Hit multiplicity for secondaries peaks at 1-2
hits, 40 % of the hits in the first two stations have no other hits and cannot be reconstructed
Efficiency drops from 0.95 to 0.7 below 10 GeV, efficiency > 95 % if 7 hits are observed.
Matching with inner track segments, which are incomplete, problematic!!!
Sascha Ierusalimov, STS track fitting
Generic simulation Uniform field used 100 m thickness throughout, 20 m resolution best resolution between 1 and 10 GeV ~ 0.7 – 1 % if all hits
are present. Vertex reconstruction
small systematic shifts < 1 m ~ 16-21 m
Results from realistic simulation (GEANT-3) Problems
broken tracks 2-hit tracks? close tracks?
G. Osakov, track reconstruction a la LIT
Old geometry used on average 1.62 ghost tracks efficiency around 80-90 % only
Pavel Akishin, Polynominal approximation
Best resolution reached in this approach. 0.4 %
Pavel Zrelov, Kalman filtering
2-dimensional projection Very precise starting points needed 20 m resolution assumed Parabola used as track model between the
detector stations 5-7
Joachim Gläß, Fast tracking
Fast Hough transform used Efficiency only above 1 GeV (cut) amounts to ~0.95 Large ghost rate Needed clock cycle 150 MHz Total number of processing units 200