johann m. heuser gsi helmholtz center for heavy ion research gmbh, darmstadt, germany 3 rd...
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Johann M. Heuser
GSI Helmholtz Center for Heavy Ion Research GmbH, Darmstadt, Germany
3rd International Conference on New Frontiers in Physics , Kolymbari, Crete, Greece, July 2014
Status of the CBM experiment
J. Heuser - Status of the CBM experiment at FAIR 2
Outline
• Compressed Baryonic Matter • Meeting the experimental challenges• The CBM experiment • Development of CBM components• Examples of performance studies• Time-line
ICNFP2014
J. Heuser - Status of the CBM experiment at FAIR 3
The CBM Physics Program
• comprehensive program to explore the phase diagram of strongly interacting matter at highest net baryon densities and moderate temperatures:
“Compressed Baryonic Matter”
• using heavy-ion collisions from 2 – 45 GeV/nucleon (sNN = 1.9 – 9 GeV) and proton-nucleus collisions at FAIR
• observables: excitation functions of yields and phase space distributions ofstrangeness, di-leptons, charm, strange matter
• few or no data at FAIR energies yet
ICNFP2014
Courtesy of K. Fukushima & T. Hatsuda
J. Heuser - Status of the CBM experiment at FAIR 4
Experimental challenges: Rare probes
ICNFP2014
min. bias Au+Au collisions at 25 AGeV (from HSD and thermal model)
SPS Pb+Pb 30 A GeVSTAR Au+Au sNN=7.7 GeV
motivating CBM experimental requirements in precision and rates
particle multiplicity branching ratio
J. Heuser - Status of the CBM experiment at FAIR 5
CBM Detector – Design constraints
High interaction rates• 105 – 107 Au+Au collisions/sec.
Fast and radiation hard detectors
Free streaming read-out • time-stamped detector data• high speed data acquisition
On-line event reconstruction • powerful computing farm • 4-dimensional tracking • software triggers
ICNFP2014
Central Au+Au collision at 25AGeVUrQMD + GEANT + CbmRoot
tracks in the Silicon Tracking System
J. Heuser - Status of the CBM experiment at FAIR 6
CBM experiment set-up
ICNFP2014
• CBM (FAIR MSV Module 1)• Cave fully designed
J. Heuser - Status of the CBM experiment at FAIR 7
CBM experiment set-up
ICNFP2014
HADES
SiliconTrackingSystem
Micro VertexDetector
Dipolemagnet
Ring ImagingCherenkovDetector
Transition Radiation Detector
Resistive Plate Chambers (TOF)
Electro-magneticCalorimeter(parking position)
Projectile SpectatorDetector
Muon Detection System(parking position)
beam dump
beam
Target
J. Heuser - Status of the CBM experiment at FAIR 8
Super-conducting dipole magnet
ICNFP2014
• aperture: 140 cm vertical, 280 cm horizontal
• weight 140 tons• field integral 1 Tm• self protecting coil: Cu/SC = 9
J. Heuser - Status of the CBM experiment at FAIR 9
Silicon Tracking in CBM
ICNFP2014
p+C, 30 GeV
few charged particles
• STS task: track identification + momentum determination - from few charged particles in p+A collisions at SIS100- to hundreds of charged tracks in A+A collisions at SIS100 and SIS300 - at 105 to 107/s collisions per second
• identification of decay topologies within its aperture • links to further detectors: MVD (upstream) and MUCH/RICH (downstream)
central Au+Au, 8 AGeV
~350 charged particles
central Au+Au, 25 AGeV
~700 charged particles
UrQMD + GEANT + CbmRoot
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System concept
ICNFP2014
Aim: a large-aperture, highly granular, low-mass detector capable of high data rates
• 8 tracking stations in dipole magnet: between 0.3 m and 1 m from target.
• Aperture: 2.5° < < 25° (38°).• Double-sided micro-strip sensors arranged
in modules on low-mass carbon-fiber supported ladders.
• Readout electronics at periphery• Target chamber/MVD/beam pipe.• Thermal enclosure, sensors at -5 ◦C.
STS
2.5°
25°
beam
target
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STS integration concept
ICNFP2014
• 8 stations, volume 2 m3, area 4 m2
• 896 detector modules- 1220 double-sided microstrip sensors- ~ 1.8 million read-out channels- ~ 16 000 r/o STS-XYTER ASICs- ~ 58 000 ultra-thin r/o cables
• 106 detector ladders with 4-5 modules• power dissipation: 42 kW (CO2 cooling)
building block: 4-5 modules per ladder
front-end board: 8 self-triggering
r/o ASICs
sensor
8 tracking stationsladdermech. unit
material budget in physics aperture
[%X0]
ultra-thin r/o cables
1 m
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Development of detector components
ICNFP2014
Silicon microstrip sensors
Module assembly
• 300 µm thick, n-type silicon• double-sided segmentation• 1024 strips of 58 µm pitch• strip length 6.2/4.2/2.2 cm• angle front/back: 7.5 deg• rad. tol. up to 1014 neq/cm2
Micro cables Front-end electronics
STS-XYTER ASIC Front-end board
64 Al lines 116 µm pitch, 10 µm thick 14 µm polyimide, up to 55 cm long
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ROB
FEB
STS Engineering: stations/cabling/cooling
FEB stack 200 Wbi-phase CO2 cooling system
STS electronics total: 42 kW
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Micro Vertex Detector
ICNFP2014
Monolithic Active Pixel Sensors (MAPS)
Pixel size: ~ 20 × 20 μm2
Position resolution: σ = 4 μm
⇒ Vertex res.: 50-100 μm (beam axis)
Radiation hardness: 1013 neq/cm2 (non-ion.), 3Mrad (ion.)Readout time: few 10 μs/frame
System integration• 2-4 stations (5, 10, 15,20 cm)• operation in vacuum • thickness per station: <0.5% X0
current prototypeMIMOSA-26:600 k Pixels104 frames/s50 μm thick
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RICH Detector
ICNFP2014
Electron identificationRadiator box filled with CO2
2 mirror arrays
photon detectors:MAPMTs (H8500,H10966, R11265)MCP-PMTs (XP85012)
e-π-Separation
MAPMT test array
full-size prototype test at CERN PS
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TRD Detector
ICNFP2014
Electron identificationπ-suppression by factor 100 (10) at SIS300 (SIS100)
Achievable with different radiator typesDifferent readout chamber types tested with and w/o (fast) drift region
SIS100:4 layers
SIS300:10 layers
Test beam at CERN-PS
TRD read-out chainSPADIC 1.0 readout chip
Extraction of different signal features in readout chain
J. Heuser - Status of the CBM experiment at FAIR 17
MUCH Detector
ICNFP2014
MUCHMUon CHamber systemMuon identification and tracking
• hadron absorbers • tracking stations
GEM
PSD
Straw tubes
Full set-up for SIS-300: 60 cm C+Pb + (20+20+30+100) cm Fe4 GEM stations + 2 straw tube stations (+ TOF)
Reduced set-up for SIS-100:60 cm C+Pb + (20+20+20) cm Fe3 GEM stations
GEM test COSY 2013
+ TOF
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TOF Detector
ICNFP2014
Test beams atGSI, ELBE/HZDR,CERN-PS,COSY
Particle identificationTime resolution ≈ 60ps
Resistive Plate Chambers (RPC)TOF wall: active area ~ 120 m2
Setupdistance to target: 10m (SIS300), 6 m (SIS100)
Hit rates:10 – 25 kHz/cm2 (2 – 10 kHz/cm2) for inner (outer) section
10 GeV
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Calorimeter Detectors
ICNFP2014
PSDParticipant Spectator Detector
determination of collision centrality and orientation of an event plane
ECALElectro-magnetic CALorimeter
detection of photons and neutral mesons (π0, η) decaying into photons
• “shashlik” type calorimeter • modules of 140 layers of 1 mm lead
and 1 mm scintillator • cell sizes 3 by 3 cm, 6 by 6 cm and 12
by 12 cm. • modules arranged in wall or in a
tower geometry with variable distances from the target.
• full compensating modular lead-scintillator calorimeter with high and uniform energy resolution.
• 44 individual modules, with 60 lead/scintillator layers, surface of 20×20 cm2.
• Read-out via wavelength shifting fibers by MAPDs
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DAQ and on-line event selection
ICNFP2014
Free streaming DAQ Time stamped message streams (no trigger!)
Total input data rate: 1 TByte/s; ~1000 input nodes
FLES: High-throughput event building and data analysis by application of massive parallelization to recons-truction algorithms and tasks.
Data reduction by up to a factor of 1000 before storage.
“GreenIT cube”FAIR Tier-0 data center (planned)
6 MW cooling, expandable to 16 MW
FLES prototypes:
LOEWE CIC, Frankfurt
Mini Cube, GSI
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Steps of event reconstruction
ICNFP2014
1. Time-slice sorting of detector hits: First step in “pre-event” definition.
2. Track finding – Cellular Automaton: Which hits in the detector layers belong to the same track? - large combinatorial problem- well to be parallelized - applicable to many-core CPU/GPU systems
3. Track fitting – Kalman Filter: Optimization of the track parameters. - recursive least squares method, fast
4. Event determination Which tracks belong to same interaction?
5. Particle finding: Identify decay topologies and other signatures.
1 2 3 4
t
hits
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Performance of hyperon measurement
ICNFP2014
5·106 central Au+Au collisions, 25 AGeV
5·106 central Au+Au collisions, 10 AGeV
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Di-lepton invariant mass spectra
ICNFP2014
e+e-
μ+μ-
ωφ J/ψ
J/ψφω
central Au+Au collisions at 25 A GeV
J. Heuser - Status of the CBM experiment at FAIR 24
Open charm measurement
ICNFP2014
D0 Kπππ D Kππ
D0 Kπππ D KππD0 Kπ
p+C collisions, 30 GeV (SIS100)
Au+Au collisions, 25 AGeV (SIS300)
1012 centr.
J. Heuser - Status of the CBM experiment at FAIR 25
Technical Design Reports
ICNFP2014
# Project TDR Status
1 Magnet approved
2 STS approved
3 RICH approved
4 TOF evaluation
5 MuCh evaluation
6 PSD evaluation
7 MVD submission 2014
8 DAQ/FLES submission 2014
9 TRD submission 2014
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Time-line
ICNFP2014
2013 2014 2015 2016 2016 2017 2018 2019 2020 2021 2022 2023 2024
construction
Installation
commissioning
expts. at SIS100 ?
expts. at SIS300
cave ready
SIS100 ready
CBM (FAIR MSV Module 1)
series productionprototypes
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CBM as experimental facility
ICNFP2014
• electron-hadron configuration• muon configuration • operation right after FAIR start-up, at SIS-100, at SIS-300 energies
example: three possible muon configurations:
“day-1” SIS-100 SIS-300
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The CBM Collaboration
ICNFP2014
12 countries, 56 institutions, 516 membershttp://www.fair-center.eu/for-users/experiments/cbm.html
Croatia: Split Univ.China:CCNU WuhanTsinghua Univ. USTC Hefei
Czech Republic:CAS, RezTechn. Univ.Prague
France: IPHC Strasbourg
Hungary:KFKI BudapestBudapest Univ.
Germany: Darmstadt TUFAIRFrankfurt Univ. IKFFrankfurt Univ. FIAS GSI Darmstadt Giessen Univ.Heidelberg Univ. P.I.Heidelberg Univ. ZITIHZ Dresden-RossendorfMünster Univ. Tübingen Univ. Wuppertal Univ.
India:Aligarh Muslim Univ.Bose Inst. KolkataB.H. Univ. VaranasiGauhati Univ.IOP BhubaneswarIIT IndoreIIT KharagpurPanjab Univ. Rajasthan Univ.Univ. of Jammu Univ. of KashmirUniv. of CalcuttaVECC Kolkata
Russia:IHEP ProtvinoINR TroitzkITEP MoscowKRI, St. PetersburgKurchatov Inst., MoscowLHEP, JINR DubnaLIT, JINR DubnaMEPHI MoscowObninsk State Univ.PNPI GatchinaSINP MSU, Moscow St. Petersburg P. Univ.
Ukraine: T. Shevchenko Univ. KievKiev Inst. Nucl. Research
Korea:Pusan Nat. Univ.
Romania: NIPNE BucharestUniv. Bucharest
Poland:AGH Krakow Jag. Univ. KrakowSilesia Univ. KatowiceWarsaw Univ.Warsaw TU
23rd CBM Collaboration Meeting, GSI, April 2014
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Back-up slides
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Detector acceptance
ICNFP2014
Au+Au 25 AGeV
Au+Au 6 AGeV ybeam = 1.28
ybeam = 1.98
J. Heuser - Status of the CBM experiment at FAIR 31
Track reconstruction performance in STS
ICNFP2014
track reconstruction efficiency momentum resolution
• realistic detector geometry, material budget and response functions• cellular automaton and kalman filter algorithms
J. Heuser - Status of the CBM experiment at FAIR 32ICNFP2014
In-beam test of a prototype STSlow-mass STS module • silicon microstrip sensors
- double-sided, 300 µm thick- 1024 strips of 58 µm pitch - front/back side strips, 7.5 deg angle- radiation tolerant up to 1014 n/cm2
• micro r/o cables (partial read-out)• self-triggering electronics
proton beam, COSY, Jülich
Results• signal amplitudes • cluster sizes • spatial resolution
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CBM online data flow
First-level Event Selector
copper ca. 0.5 m
optical some 10 m
optical 100s m
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STS-XYTER ASIC
ICNFP2014
STS-XYTER ASIC
• purely data driven read-out• time-stamped data elements
channels 128, polarity +/-
noise 900 e- at 30 pF load
ADC range 16 fC, 5 bit
clock 250 MHz
power < 10 mW/channel
timestamp < 5 ns resolution
out interface 4(5) × 500 Mbit/s LVDS
v1.0 produced(v2.0 under design) UMC 180 nm CMOS
every channel is divided into two sub-channels:
• fast branch: time-stamp• slow branch: signal digitization
noise minimization in self-triggering system:
effective two-level discrimination
• trigger to the timestamp latch is vetoed if ADC-LSB generated no signal
• no transmission of data then
CBM-NET
(v1.0 )
GBT(V2.0)
LSB veto
ts = 30 ns
ts = 80 ns
r/ologic
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STS Read-out electronics
ICNFP2014
STS-XYTER ASIC
GBTx chip-set (CERN):3 GBTx, 1 VTRx, 1 VTTx, 1 SCA
42 E-links à 320 Mb/s 3 GBT optical uplinks à 4.48 Gb/s
Front-end Board Read-Out Board
Data Processing Boardtime-slicing
FLES farmonline event computing
• purely data driven read-out• time-stamped data elements
8 STS-XYTER chips1/2/5 LVDS links out
separate power boards
channels 128, polarity +/-
noise 900 e- at 30 pF load
ADC range 16 fC, 5 bit
clock 250 MHz
power < 10 mW/channel
timestamp < 5 ns resolution
out interface 4(5) × 500 Mbit/s LVDS
v1.0 produced(v2.0 under design) UMC 180 nm CMOS
data combiningtime-stamped data