The ATLAS Detector - Nevis Laboratoriesparsons/teach/ATLAS...ATLAS Inner Detector TRT Pixels SCT...
Transcript of The ATLAS Detector - Nevis Laboratoriesparsons/teach/ATLAS...ATLAS Inner Detector TRT Pixels SCT...
The ATLAS Detector
(see http://atlas.web.cern.ch/Atlas/Welcome.html)
ATLAS
The Large The Large HadronHadron ColliderCollider at CERN (LHC)at CERN (LHC)
7+7 TeV pp collider25 ns bunch spacing≈ 20 int./crossing
at high luminosity⇒ ≈ 800 million pp collisions per second
Example data sets10 fb-1 (one yr. at
low lumi.)6x1012 b-bbar2x109 W5x108 Z8x106 ttbar2x105 H (mH=150)
Scheduled to begin running in 2007
Particle Detection Principles
The ATLAS Detector
Overall length = 42 m, diameter = 22 m, weight = 7000 tons
Components under construction in over 35 countries around the world
ATLAS Underground Cavern
civil engineering finished April 2003installation of detector components is underway
Webcam picture from May 28/2004
ATLAS Inner Detector
TRT
Pixels SCT
Barrelpatch panels
End-cappatch panels
Services
Beam pipe
r = 1.15 m, length = 7 m ( |η| < 2.5 ), 2 T solenoidal magnetic field
3 layers (r = 4, 11, 14 cm) of 50 µm X 300 µm Si pixels (140E6 in total)4 layers of 80 µm X 12.8 cm Si strips (6.2E6 in total)36 layers of 4 mm dia. X 1.5 m (max) straws (420k in total)
Barrel SCT
ATLAS Inner Detector
Integration of SCT into Barrel TRT
ATLAS Inner Detector Performance
ATLAS Barrel Inner DetectorH→bb
–
b
b–
ATLAS Barrel Inner DetectorH→bb
–
b
b–
Low luminosity Design luminosity
ATLAS Inner Detector Performance (cont’d)
0
50
100
150
200
1 10 102
With B-layerWithout B-layer
|η| < 0.25
pT (GeV)
σ(d 0)
(µm
)
0
100
200
300
1 10 102
With B-layerWithout B-layer
|η| < 0.25
pT (GeV)
σ(z 0)
(µm
)
ATLAS Calorimeters
Calorimeters
Calorimeters
Calorimeters
Calorimeters
Hadronic Tile
EM Accordion
Forward LAr
Hadronic LAr End Cap
The ATLAS Liquid Argon Electromagnetic Calorimeter
47 cm
readout electrode absorber
P
leadglue
kapton
outer copper layer
outer copper layer
inner copper layer
stainless steel
HVHV
liquid
argo
n gap
liquid
argo
n gap
(~2 m
m)
0.7%E
10%E
σ(E)⊕≈
The ATLAS Liquid Argon Calorimeter
0
10
20
30
40
0 1 2 3Pseudorapidity
X0
Barrel-Endcap crack
Presampler
Scintillator
ID services+ patch panel
warm flange
cables + passive liquidMaterialin front of Presampler
Materialin front of Accordion
B A R R E L E N D C A P
Materialin front ofAccordion
Material up to the end of active BarrelMaterial up to the end of active Endcap
Total active depth
The ATLAS LAr Barrel Wheel Assembly
The ATLAS Barrel Cryostat and Superconducting Solenoid
The ATLAS Barrel Cryostat Installation
At Columbia, we have designed and are starting production of the readout electronics for the ATLAS LAr calorimeters
LAr Calorimeter Readout Electronics
read out ≈ 170k channels of calorimeterdynamic range ≈ 16 bitsmeasure signals at bunch crossing frequency of 40 MHz (ie. every 25 ns)store signals during L1 trigger latency of ≈ 2.5 µs (100 bunch crossings)digitize and read out 5 samples/channel at L1 rate of ≈ 100 kHz
measure deposited energies with resolution < 0.25%measure times of energy depositions with resolution << 25 ns
high density (128 channels per board)low power (≈ 0.8 W/channel)high reliability over expected lifetime of > 10 yearsfor on-detector electronics, be tolerant of significant levels of radiation due to intense particle collisions
Requirements of ATLAS LAr Readout
functionality includes:receive input signals from calorimeteramplify and shape themstore signals in analog form while awaiting L1 triggerdigitize signals for triggered eventstransmit output data bit-serially over 1.6 Gbps optical link off detector
Overview of ATLAS Overview of ATLAS LArLAr calorimeter calorimeter frontendfrontend board (FEB)board (FEB)
Overview of main FEB components
32 SCA 16 ADC 8 Gain Select.
1 Glink
1 Config.2 SCAC
1 SPAC
1 MUX
32 Shaper
1 TTCRx
2 CLKFO
20 Regulators 4 LSB
32 0T
128input
Signalsfm calo
1 fiberTo RODs
8 sumsTo TBB
DMILL
DSM
AMS
COTS
FEB Prototype Results
DAC setting-Equivalent Energy Channel(GeV)
RMS = 50MeV RMS = 500MeV
101
102
103
10-1
100
0 20 40 60 80 100 120 140 160 180 200
100
10-1
10-2
2
5
2
5
Electron Energy (GeV)
Tim
ing
Res
olut
ion
(ns)
/E(%
)σ E 2
5
2
5
Time (ns)
Am
plitu
de (
AD
C c
ount
sx10
00)
200 300 400 500
0.0
-0.5
0.5
1.0
1.5
2.0
ATLAS Tile Hadronic Calorimeter
Doublereadout
Hadrons
zr
φ
3%E
30%E
σ(E)⊕≈
ATLAS Calorimetry Depth and Missing ET
0
5
10
15
20
0 1 2 3 4 5Pseudorapidity
Abs
orpt
ion
Len
gth
Tile barrel
Tileextended barrel Hadronic endcap Forward calorimeter
EM barrel EM endcap
Material in front of Muon System
End of activehadronic
cryostat walls
0
5
10
15
0 100 200 300 400 500ΣET in calorimeters (GeV)
σ(p xm
iss ,
p ymis
s ) (
GeV
)
low luminosity new data
ATLAS Toroidal Muon Spectrometer
2
4
6
8
10
12 m
00
Radiation shield
MDT chambers
End-captoroid
Barrel toroid coil
Thin gap chambers
Cathode strip chambers
Resistive plate chambers
14161820 21012 468 m
3 superlayers of tracking chambers (370k drift tubes, 67k CSC) and trigger chambers (355k RPC, 440k TGC)total detector area > 12k m2
toroidal magnetic field provided by array of air-core toroids
ATLAS Muon Detectors
170 t (90 km) superconductor, 700 t cold masstotal stored energy 1.55 GJ
ATLAS Toroidal Magnet System
0
2.5
5
7.5
10
0 1 2η
∫Bdl
(T
m)
φ = π/8
φ = 0
Barrel region End-cap region
Tran
sitio
n re
gion
ATLAS Barrel Toroid Installation
ATLAS Endcap Toroids
ATLAS Muon Momentum Resolution
Energy loss fluctuationsMultiple scattering
Chamber resol and align.
Muon spectrom.standalone
Inner trackerstand alone
The The muonmuon spectrometer resolution spectrometer resolution dominates for Pt > 100 dominates for Pt > 100 GeV/GeV/cc
ATLAS Status Today
Follow progress on Webcams at Follow progress on Webcams at http://atlaseyehttp://atlaseye--webpub.web.cern.ch/atlaseyewebpub.web.cern.ch/atlaseye--webpub/webwebpub/web--sites/pages/UX15_webcams.htmsites/pages/UX15_webcams.htm