Status of the Silicon Tracking System
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Transcript of Status of the Silicon Tracking System
J.M. Heuser − Status of the Silicon Tracking System 1
Status of the Silicon Tracking Status of the Silicon Tracking SystemSystem
Johann M. Heuser, CBM Collaboration Meeting, GSI, 28.2.2008
News and update on
Layout studies, realistic detector response
Radiation environment
Prototyping of detectors and components
R&D Cooperations, Tasks
J.M. Heuser − Status of the Silicon Tracking System 2
STS detector layoutSTS detector layout8 stationsdouble-sided silicon micro-strip detectors, thickness 300m
Building block is a low-mass ladder structure
Support made of carbon boxes
Cables represented as capton boxes, thickness 200m
Readout electronics: thick layers of silicon and aluminium
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Sectors: 6cm wide, 2 - 18 cm high
Station layoutStation layout
About 1.2 million channels total. Occupancy reaches 5.7% in central Au+Au collisions at 25 AGeV.
Station 1
Station 8
(R. Karabowicz)
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Tracking resultsTracking results
OLD SETUP WITHOUT ADDITIONAL MATERIAL
tracking eff. 96.18 %
mom. resol. 1.3 %
NEW SETUP WITHOUT ADDITIONAL MATERIAL
tracking eff. 90.3 %
mom. resol. 1.6 %
OLD SETUP WITH ADDITIONAL MATERIAL
tracking eff. 93.8 %
mom. resol. 1.7 %
NEW SETUP WITH ADDITIONAL MATERIAL
tracking eff. 87.9 %
mom. resol. 1.6 %
(R. Karabowicz)
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Realistic detector response (I)Realistic detector response (I)
Sector view:Front strips in blueBack strips in greenMC points in circlesReconstructed hits: stars
Size of plot [cm]Position in STS:XYZ
Front strips’ ADC distributionBack strips’ ADC distribution
Simple Event Display
(R. Karabowicz)
so far: single strips underneath Geant hits activated
now: charge chared by several strips
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Realistic detector response (II)Realistic detector response (II)
Problem:
wide, overlapping clusters in the most upstream stations
To be answered:
Do we require pixel detectors in the first STS stations?
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Tracking results - incl. clusteringTracking results - incl. clusteringClustering included
tracking eff. 74.5 %
mom. resol. 1.6 %
Work in progress: DIGITIZER: TOO SIMPLEHIT FINDER: TOO SIMPLE
Station 1 Station 8
(R. Karabowicz)
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Radiation environmentRadiation environment
DPM
UrQmd
iFluka framework (D. Bertini) 1-MeV neutron equivalent fluences in CBM cave
(beam dump)
(interaction in target)
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Radiation assessment in CBM (I)Radiation assessment in CBM (I)
per min. bias UrQMD event, 25 AGeV
(D. Bertini)
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MUCH scoring planes
MDV+STS Scoring planes
Radiation assessment in CBM (II)Radiation assessment in CBM (II)
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Dose in 6 years of CBM running:
~ 3 1014 nequiv.
Very Significant !!
Neutron fluence in STSNeutron fluence in STSSTS 5 STS 6
STS 7 STS 8
back scattering from MUCH absorber
~ 1 nequiv. per min. bias interaction
min. bias UrQMD @ 25 AGeV
(D. Bertini)
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Ionizing dose Ionizing dose Calculated with GEANT for 6 years* of CBM running.
*1 year = 2 months at 107 int/s
Station 8, z =100cmStation 4, z =50cm
Station 1, z =30cm
comparable result with FLUKA
(R. Karabowicz)
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Geometry composed of 28 stationsFirst station has vertical stripsSecond station has stereo strips 0.5 cm distance between stations.
Digitizer developedIdeal hit finder combining strips belonging to one track.Modified L1 tracking
STS built from single-sided strip detectorsSTS built from single-sided strip detectorsWhy to study
Technology "radiation hard" May be easier to construct
Tracking efficiency ~ 80 %no advanced features included (e.g. no computing speed optimization)
a b
a
b
First trials: (R. Karabowicz) (I. Kisel)
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Microstrip detector Microstrip detector prototype CBM01, 8/2007prototype CBM01, 8/2007
4" wafer, 285 µm Si Test sensors
Double-sided, double-metal, 1024 strips per side, 50 µm pitch, 15º stereo angle, full-area sensitive, contacts at top + bottom edge, size: 5656 mm2
Double-sided, single-metal, 256256 strips, orthogonal, 50(80) µm pitch, size: 1414 (22 22) mm2
Main sensor
CBM01
CBM01B1
CBM01B2
Designed to explore CBM-specific connectivity
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Towards 2Towards 2ndnd design iteration design iterationCIS activity in frame of german BMWI project INNOWAT -“SPID“
L. Long and R. Rolf, CIS
Test wafer to explore primarily
radiation tolerance
Full detectors
7 pixel detectors; 18 strip detectors.
Test structures:
3 Pad diodes, 4 Gate diodes,
6 PDTF, 2 SIMS, 2 SDM.
Process status 2/2008:
First active implant finished.
poly silicon bias structures
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Characterization of CBM01 at CISCharacterization of CBM01 at CIS
IV and CV characterization of CBM01B1, CBM01B2, CBM02 (W. John et al.)
reported at CBM Meeting September 2007
U [V]
I [µ
A]
U[V]
I [µ
A]
U [V]
1/C
2 [p
F-
2]
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Find application in various activities of Find application in various activities of beginning detector module R&Dbeginning detector module R&D
Only currently available CBM-specific microstrip detectors. Very important for STS prototyping!!
GSI: Test board (CBM01B2, preparation, report A. Lymanets)
Test beam tracking module (planned)
KINR Kiev: Pre-prototype module & CBM01B1 detector tests (electrical, diode laser, radioactive source) (report V. Pugatch)
Kharkov/JINR: Test board with microcable fanout structure (planned)
Cracow: n-XYTER-SUCIMA board with CBM01B2 (planned)
+ many new ideas around
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Detector test board, GSIDetector test board, GSI
produced 2/2008
(A. Lymanets, J. Heuser)
test global detector characteristics
e.g. IV, CV
access both detector sides
contact a few strips for detailed measurements, including n-XYTER readout
do all this as quickly and as simple as possible to start work
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DDetector module etector module pre-pre-prototypeprototypes, KINR Kiev s, KINR Kiev
CBM01-B1 detector:
p-side on test board
CBM01 detector, chip cable on carbon fibre support
(V. Pugatch)
J.M. Heuser − Status of the Silicon Tracking System 20 HV = 50 V HV = 70 V
Mapping of inter-strip charge charing with laser positioning system
CBM01-B1226 Ra from p-side, p-strips 5@6
CBM01 – first measurements at KINR CBM01 – first measurements at KINR
ES
trip
E Strip+1
0 10 20 30 40 50 60 700
0.1
0.2
0.3
0.4
0.5
0.6
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0.8
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1
Voltage, V
Cu
rren
t,
A
VA - characteristic
Vitya (16.02.08 am)Sasha (21.02.08)V.O. (16.02.08 pm)
U [V]
I [µ
A]
Current-Voltage behaviour
(V. Pugatch)
Charge collection near surface
µm
ES
trip
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Analog readout cable.
55 cm long, 1024 lines, 100 µm pitch55 cm long, 1024 lines, 100 µm pitch
14 µm Al on 10 µm Kapton14 µm Al on 10 µm Kapton
(V. Borshchov et al.)1024 strips50 µm pitch2 cm long
Readout cables, SE SRTIIE KharkovReadout cables, SE SRTIIE Kharkov
first pre-prototypes produced
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R&D cooperations, tasksR&D cooperations, tasksISTC project:
“CBM Silicon Tracker“ (GSI, KRI St. Petersburg, MSU Moscow, IPHC Strasbourg)
HadronPhysics2 I3 JRA:HadronPhysics2 I3 JRA: 9/2007 9/2007Proposal: “Ultra-thin silicon tracking and vertex detection systems“
... decision in 2008 ...CBM STS Consortium: 2008 - 2010
JINR-SINP-KRI-SPbSU-SESRITIIE-BTI-(IHEP)-GSI
GSI R&D cooperations:
GSI-Kiev Inst. for Nucl. Research
Finnland: FAIR member, in-kind contribution to CBM
"single-sided rad-hard microstrip detectors"
project under preparation
To build and test a prototype(s) of the CBM STS Ladder
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SummarySummarySTS still in conceptual design phase.
Progress with essential details, missing so far, is being made, including:
Realistic detector response (signal sharing, clusters)
Hit densities: - Strip technology in most upstream stations? - Are pixel detectors required?
Radiation study: How harsh are the operation conditions?
Deep consequences for the detector technologies and operating scenario.
Explore technologies: Double/single-sided strip detectors, AC/DC coupling...
Detector module concept: Very challenging design in mind, motivated by the low-mass requirement of our physics. Doable?
Risk management: Identify potential failures, redundant approaches, conservative and aggressive technical solutions.
Detector R&D: Essential. Becomes lively! Teams are forming. Preparations of test systems, test beams!
To aid this: Latest insights/results will be compiled in a technical document.