1. The ATLAS Experiment Getting
Ready for LHC
Physics at LHC, Cracow,
4th July 2006 (P. Jenni, CERN)
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

2. ATLAS Collaboration (As of the March 2006) 35 Countries
158 Institutions
1650 Scientific Authors total
(1300 with a PhD, for M&O share)
New application for CB decision in July
DESY, Humboldt U Berlin (Germany)
SLAC, New York U (US)
Albany, Alberta, NIKHEF Amsterdam, Ankara, LAPP Annecy, Argonne NL, Arizona, UT Arlington, Athens, NTU Athens, Baku, IFAE Barcelona, Belgrade, Bergen, Berkeley LBL and UC, Bern, Birmingham, Bologna, Bonn, Boston, Brandeis, Bratislava/SAS Kosice, Brookhaven NL, Buenos Aires, Bucharest, Cambridge, Carleton, Casablanca/Rabat, CERN, Chinese Cluster, Chicago, Clermont-Ferrand, Columbia, NBI Copenhagen, Cosenza, AGH UST Cracow, IFJ PAN Cracow, Dortmund, TU Dresden, JINR Dubna, Duke, Frascati, Freiburg, Geneva, Genoa, Giessen, Glasgow, LPSC Grenoble, Technion Haifa, Hampton, Harvard, Heidelberg, Hiroshima, Hiroshima IT, Indiana, Innsbruck, Iowa SU, Irvine UC, Istanbul Bogazici, KEK, Kobe, Kyoto, Kyoto UE, Lancaster, UN La Plata, Lecce, Lisbon LIP, Liverpool, Ljubljana, QMW London, RHBNC London, UC London, Lund, UA Madrid, Mainz, Manchester, Mannheim, CPPM Marseille, Massachusetts, MIT, Melbourne, Michigan, Michigan SU, Milano, Minsk NAS, Minsk NCPHEP, Montreal, McGill Montreal, FIAN Moscow, ITEP Moscow, MEPhI Moscow, MSU Moscow, Munich LMU, MPI Munich, Nagasaki IAS, Naples, Naruto UE, New Mexico, Nijmegen, BINP Novosibirsk, Ohio SU, Okayama, Oklahoma, Oklahoma SU, Oregon, LAL Orsay, Osaka, Oslo, Oxford, Paris VI and VII, Pavia, Pennsylvania, Pisa, Pittsburgh, CAS Prague, CU Prague, TU Prague, IHEP Protvino, Ritsumeikan, UFRJ Rio de Janeiro, Rochester, Rome I, Rome II, Rome III, Rutherford Appleton Laboratory, DAPNIA Saclay, Santa Cruz UC, Sheffield, Shinshu, Siegen, Simon Fraser Burnaby, Southern Methodist Dallas, NPI Petersburg, Stockholm, KTH Stockholm, Stony Brook, Sydney, AS Taipei, Tbilisi, Tel Aviv, Thessaloniki, Tokyo ICEPP, Tokyo MU, Toronto, TRIUMF, Tsukuba, Tufts, Udine, Uppsala, Urbana UI, Valencia, UBC Vancouver, Victoria, Washington, Weizmann Rehovot, Wisconsin, Wuppertal, Yale, Yerevan
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

3. Construction, integration and installation progress of the ATLAS detector
ATLAS superimposed to
the 5 floors of building 40
Diameter m
Barrel toroid length 26 m
End-cap end-wall chamber span 46 m
Overall weight Tons
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

4. The Underground Cavern at Pit-1 for the ATLAS Detector Length = 55 m
Width = 32 m
Height = 35 m
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

5. An Aerial View of Point-1
(Across the street from the CERN main entrance)
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

6. ATLAS Tracking (||<2.5, B=2T) : Length : ~ 46 m Radius : ~ 12 m
Weight : ~ 7000 tons
~ 108 electronic channels
~ 3000 km of cables
Tracking (||<2.5, B=2T) :
-- Si pixels and strips
-- Transition Radiation Detector (e/ separation)
Calorimetry (||<5) :
-- EM : Pb-LAr
-- HAD: Fe/scintillator (central), Cu/W-LAr (fwd)
Muon Spectrometer (||<2.7) :
air-core toroids with muon chambers
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

7. Physics example H  ZZ  4  Z(*) Z mZ e, mg t
Z(*)
H  ZZ  4 
“Gold-plated” channel
for Higgs discovery
at LHC
Signal expected in ATLAS
after ‘early' LHC operation
Simulation of a H   ee event in ATLAS
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

8. Magnet System Central Solenoid 2T field with a stored energy of 38 MJ
Integrated design within the barrel LAr
cryostat
The solenoid has been
inserted into the LAr cryostat
at the end of February 2004,
and it was tested at full current
(8 kA) during July 2004
It is now cold, and has been
successfully tested in situ at
a reduced current (awaiting
the end-caps for field mapping
at full current in August 2006)
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

9. Toroid system Barrel Toroid: 8 separate coils End-Cap Toroid:
Barrel Toroid parameters
25.3 m length
20.1 m outer diameter
8 coils
1.08 GJ stored energy
370 tons cold mass
830 tons weight
4 T on superconductor
56 km Al/NbTi/Cu conductor
20.5 kA nominal current
4.7 K working point
End-Cap Toroid parameters
5.0 m axial length
10.7 m outer diameter
2x8 coils
2x0.25 GJ stored energy
2x160 tons cold mass
2x240 tons weight
4 T on superconductor
2x13 km Al/NbTi/Cu conductor
20.5 kA nominal current
4.7 K working point
Barrel Toroid:
8 separate coils
End-Cap Toroid:
8 coils in a common cryostat
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

10. Barrel Toroid construction
Series integration and tests of the
8 coils at the surface were finished
in June 2005
BT test area
BT5 excitation tests
to 22 kA current
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

11. Barrel Toroid coil transport and lowering into the underground cavern
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

12. The first coil was installed in October 2004
Latest news: the system
is being cooled down in
situ, and current tests
will start in August 2006
The last coil was moved into position on 25th August 2005
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

13. End-Cap Toroids
All components are fabricated, and the assembly is now ongoing at CERN
The ECTs will be tested at 80 K on the surface, before installation and excitation tests in the cavern
The first ECT will move to the pit in October 2006, the second one in early 2007
The first of the two ECT
cold masses inserted into
the large vacuum vessel
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

14. Inner Detector (ID) The Inner Detector (ID) is organized
into four sub-systems:
Pixels
( channels)
Silicon Tracker (SCT)
(6 106 channels)
Transition Radiation Tracker (TRT)
(4 105 channels)
Common ID items
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

15. Pixels
The Pixel project progresses well, but it was affected by two technical problem that require highest
priority recovery actions:
Corrosion leaks in the barrel cooling tubes (now under control, repair ongoing)
Broken low-mass cables for the barrel services (repair/replacement strategy being
put into place)
At this stage the schedule is very tight and on the critical path, but all efforts are made
to have the full system ready for installation in time for May 2007
The installation schedule has been adapted as to accommodate the late availability
(Note that the Pixel sub-system can be installed independently from the rest of the Inner Detector)
Two bi-staves assembled (final) in the L1 half-shell; L1 and L2 assembly proceed in parallel
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

16. The rate for assembled and fully qualified modules meets the needs
for a 3-hit system in time
(1744 modules needed)
Assembly and integration, as well as
preparation of the installation tools,
proceed according to schedule
The first complete end-cap arrived at
CERN few weeks ago, and it will soon
undergo cosmic ray tests in the surface
clean room SR1
Three completed Pixel disks
(one end-cap) with 6.6 M channels
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

17. Silicon Tracker (SCT)
All four barrel cylinders are complete and at CERN
The pictures show different stages of the integration of
the four barrel SCT cylinders
The cylinders have been tested before: 99.7% of all channels
fully functional
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

18. End-cap SCT All disks for the end-caps are finished as well
The first end-cap arrived end of February
2006 at CERN, the second one in April 2006
A completed end-cap SCT disk
(Picture taken by a star-photographer, P. Ginter, as art-work…)
Integration work on one of the end-cap SCT
cylinders
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

19. Transition Radiation Tracker (TRT)
The module construction for the TRT is complete
The barrel integration has been finished since about a year
The first end-cap side (A and B wheels) has been stacked, the second side will be
ready in June 2006, they are now being equipped with services
The first of the two
end-cap TRTs
(A and B type wheels)
fully assembled
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

20. surface clean room facility SR1
Examples of cosmic ray registered in the barrel TRT in the Inner Detector
surface clean room facility SR1
Barrel TRT during insertion of the
last modules (February 2005)
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

21. at the surface with cosmics
End of February 2006 the barrel SCT was inserted into the barrel TRT, and this component
will be ready for the final installation in ATLAS in August 2006 after further commissioning
at the surface with cosmics
Integrations of the two end-caps (SCT and TRT) are ongoing for installation end of 2006
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

22. Cosmics in the barrel TRT plus SCT
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

23. Inner Detector services (cables and pipes) installation in the inner bore of
the barrel cryostat
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

24. LAr and Tile Calorimeters
Tile barrel
Tile extended barrel
LAr hadronic
end-cap (HEC)
LAr EM end-cap (EMEC)
LAr EM barrel
LAr forward calorimeter (FCAL)
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

25. LAr EM Barrel Calorimeter Commissioning at the Surface
After many years of module constructions, the barrel EM calorimeter was installed in the cryostat,
and after insertion of the solenoid, the cold vessel was closed and welded early 2004
A successful complete cold test (with LAr) was made during summer 2004 in hall 180 at CERN
(dead channels much below 1%)
LAr barrel EM calorimeter module at one
of the assembly labs
LAr barrel EM calorimeter after insertion into the
cryostat
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

26. End of October 2004 the cryostat was
transported to the pit, and lowered
into the cavern
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

27. Barrel LAr and Tile Calorimeters A cosmic ray muon registered
in the barrel Tile Calorimeter
The barrel LAr and scintillator tile calorimeters have
been since January 2005 in the cavern in their ‘garage
position’ (on one side, below the installation shaft)
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

28. November 4th 2005: Calorimeter barrel after its move into the
center of the ATLAS detector
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

29. Latest news: Cool-down completed, filled with LAr, in-situ
commissioning started...
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

30. LAr End-Caps The surface cold tests with LAr are finished, with
very good results (dead channels well below 1%)
FCAL A before insertion
End-Cap cryostat A before the
insertion of the FCAL and closure
End-Cap A during the surface cold tests
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

31. End-Cap LAr and Tile Calorimeters
The end-cap calorimeters on side C were assembled in the cavern by end of
January 2006, and then moved partially into the ATLAS detector centre, in order
to free the space under shaft C for muon end-cap installation
The mechanical installation of the second end-cap is finished now as well
Completed end-cap calorimeter side C, just before, and after, the partial insertion into the detector
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

32. Calorimeter electronics
LAr FE crate
The installation of the LAr Front End (FE) electronics on
the detector, as well as of the Back End (BE) read-out
electronics in the control room, is proceeding to plans
A particular concern are still the in-time availability of
the low and high voltage LAr power supplies
For the Tile Calorimeter, a control problem for the low
voltage supplies has been understood, and a corrective
action is being implemented
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)
LAr barrel ROD system in USA15

33. EM beam test results: Energy resolution
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

34. Impact on Higgs mass resolution
Simulations, mH=130 GeV
Events
H  4 e
H  
Resolution: 1% (low lum)
1.2% (high lum)
Acceptance: 80% within ±1.4 
H  4e
Resolution: 1.2% (low lum)
1.4% (high lum)
Acceptance: 84% within ±2 
Mass(GeV)
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

35. Muon Spectrometer Instrumentation
The Muon Spectrometer is instrumented with precision chambers and fast trigger chambers
A crucial component to reach the required accuracy is the sophisticated alignment measurement and monitoring system
Precision chambers:
- MDTs in the barrel and end-caps
- CSCs at large rapidity for the
innermost end-cap stations
Trigger chambers:
- RPCs in the barrel
- TGCs in the end-caps
At the end of February 2006 the huge and long effort of series chamber production in many sites
was completed for all chamber types
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

36. Barrel MDTs Installation of barrel muon station (40% done)
A major effort is spent in the preparation and
testing of the barrel muon stations (MDTs and
RPCs for the middle and outer stations) before
their installation in-situ
The electronics and alignment system
fabrications for all MDTs are on schedule
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

37. First cosmics have been registered in situ for barrel chambers
In December 2005 in MDTs and in June 2006 in RPCs
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

38. End-cap muon chamber sector preparations 72 TGC and 32 MDT ‘Big-Wheel’
sectors have to be assembled
‘Big Wheel’ end-cap MDT sector
This work is in full swing in the Hall 180 where previously the Barrel Toroid and the LAr integration and tests were done
‘Big Wheel’ end-cap TGC sectors
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

39. Preparations for the Big Wheels installation in the underground cavern have started
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

40. aspects, with sample series chamber station in the SPS H8 beam
The large-scale system test facility for alignment, mechanical, and many other system
aspects, with sample series chamber station in the SPS H8 beam
Shown in this picture is the end-cap set-up, it is preceded in the beam line by a barrel sector
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

41. Example of tracking the sagitta measurements, following the day-night variation due to thermal
variations of chamber and structures, and two forced displacements of the middle chamber
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

42. Trigger, DAQ and Detector Control
Calo MuTrCh
Other detectors
40 MHz
40 MHz
75 kHz
~2 kHz
~ 200 Hz LV L1 D E T
R/O
Read-Out Drivers
FE Pipelines
Read-Out Sub-systems
Read-Out Buffers
Read-Out Links
2.5 ms
LVL2
~ 10 ms
ROIB
L2P
L2SV
L2N
RoI
RoI data = 1-2%
requests
Lvl1 acc = 75 kHz
ROD
ROD
ROD
120 GB/s
~ 300 MB/s
~2+4 GB/s
ROS
GB/s
ROB H L T D A T F L O W
RoI Builder
L2 Supervisor
L2 N/work
L2 Proc Unit EB
SFI
EBN
DFM
Lvl2 acc = ~2 kHz
Event Building N/work
Dataflow Manager
Sub-Farm Input
Event Builder
EFN
SFO
Event Filter
EFP
~ sec
~4 GB/s
EFacc = ~0.2 kHz
Event Filter N/work
Sub-Farm Output
Event Filter
Processors
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

43. ATLAS Trigger / DAQ Data Flow
LVL2
Super-
visor
SDX1
CERN
computer
centre
DataFlow
Manager
Event
Filter
(EF)
pROS
~ 500
~1600
stores
output
dual-CPU nodes
~100
~30
Network
switches
Event data
pulled:
partial events
@ ≤ 100 kHz,
full events
@ ~ 3 kHz
Event rate
~ 200 Hz
Data
storage
Local
Storage
SubFarm
Outputs
(SFOs)
farm
Network switches
Builder
Inputs
(SFIs)
ATLAS
detector
Read-
Out
Drivers
(RODs)
First-
level
trigger
Read-Out
Subsystems
(ROSs)
UX15
USA15
Dedicated links
Timing Trigger Control (TTC)
1600
Links
Gigabit Ethernet
RoI
Builder
pROS
Regions Of Interest
VME
~150
PCs
Data of events accepted
by first-level trigger
Event data requests
Delete commands
Requested event data
stores
LVL2
output
Event data ≤ 100 kHz,
1600 fragments of ~ 1 kByte each
Second-
SDX1
USA15
UX15
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

44. Level-1
The level-1 system (calorimeter, muon and central trigger logics) is in the
production and installation phases for both the hardware and software
The muon trigger sub-system faces a very tight schedule for the on-chamber
components, but is now proceeding satisfactorily
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

45. HLT/DAQ/DCS
The High Level Trigger (HLT), Data Acquisition (DAQ) and Detector Control System (DCS)
activities have continued to proceed according to plans
Large scale system tests, involving up to 800 nodes, have further demonstrated the required
system performance and scalability
Scalability is particularly important for staging needs during the initial running of ATLAS
A major emphasis was put on all aspects of the HLT and DAQ software developments
Example of performance optimization
Components of the DCS are in fabrication or already finished (ELMB), and are already widely used, and the s/w components are available
The DCS is one of the first systems already in operation at Pit-1
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

46. Almost 1/3 of the final Read Out System (ROS) has been installed and commissioned in the underground control room USA15
The infrastructure at Point-1 is now fully active (including central file server and a number of local service machines with standard DAQ software, system administration, and networking)
ROS racks for the LAr
The pre-series of the final system at Point-1 (10% of final dataflow) is now in operation at Point-1
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

47. Inner detector Calorimetry Muon system Trigger
Channels
No. ROLs
Fragment size - kB
Pixels
0.8x108
120
0.5
SCT
6.2x106 92
1.1
TRT
3.7x105
232
1.2
ATLAS total event size = 1.5 MB
Total no. ROLs = 1600
Calorimetry
Channels
No. ROLs
Fragment size - kB
LAr
1.8x105
764
0.75
Tile
104 64
Muon system
Channels
No. ROLs
Fragment size - kB
MDT
3.7x105
192
0.8
CSC
6.7x104 32
0.2
RPC
3.5x105
0.38
TGC
4.4x105 16
Trigger
Channels
No. ROLs
Fragment size - kB
LVL1 56
1.2
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

48. ATLAS Computing Timeline
2003
POOL/SEAL release (done)
ATLAS release 7 (with POOL persistency) (done)
LCG-1 deployment (done)
ATLAS complete Geant4 validation (done)
ATLAS release 8 (done)
DC2 Phase 1: simulation production (done)
DC2 Phase 2: intensive reconstruction (re-scheduled)
Combined test beams (barrel wedge) (done)
Computing Model paper (done)
Computing Memorandum of Understanding (done)
ATLAS Computing TDR and LCG TDR (done)
Start of Computing System Commissioning (in progress)
Physics Readiness Documents (re-scheduled: early 2007)
Start cosmic ray run
GO!
2004
2005
2006
2007
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

49. goals, preconditions, clients and quantifiable acceptance tests
The computing and software suite has progressed on a very broad front, with a
particular emphasis to make it as accessible as possible to the user community
Examples: GRID production tools
Software infrastructure
Detector Description and graphics
Framework and Event Data Model
Simulation
Tracking (ID and Muons) and calorimeters (LAr and Tiles)
Database and data management
Reconstruction and Physics Analysis tools
Distributed analysis
Computing System Commissioning along sub-system tests with well-defined
goals, preconditions, clients and quantifiable acceptance tests
Examples: Full Software Chain
From generators to physics analysis
Tier-0 Scaling
Calibration & Alignment
Trigger Chain & Monitoring
Distributed Data Management
Distributed Production (Simulation & Re-processing)
(Distributed) Physics Analysis
General ‘rehearsal’ of TDAQ/Offline data flow and analysis
ATLAS computing is fully embedded in, and committed to, the LCG framework
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

50. Input from 350 k jobs 138 sites in 29 countries
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

51. ATLAS Installation Schedule Version 8.0
- Beam pipe in place end of August 2007
- Restricted access to complete end-wall muon chambers and global commissioning until mid-Oct 2007
- Ready for collisions from mid-October 2007
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

52. Figure 2 Operation Model (Organization for LHC Exploitation) CB
(Details can be found at )
Executive Board
ATLAS management: SP, Deputy SP, RC, TC
Collaboration Management, experiment execution, strategy, publications, resources, upgrades, etc.
Publication
Committee,
Speaker
Committee CB
Detector Operation
(Run Coordinator)
Detector operation during data taking, online data quality, …
Trigger
(Trigger Coordinator)
Trigger data quality,
performance, menu tables, new triggers, ..
Data Preparation
(Data Preparation Coordinator)
Offline data quality,
first reconstruction of physics objects,
calibration, alignment
(e.g. with Zll data)
Computing
(Computing Coordinator)
Core Software, operation of offline computing, …
Physics
(Physics Coordinator)
optimization of algorithms for physics objects, physics channels
Figure 2
(Sub)-systems:
Responsible for operation and calibration of their sub-detector and for sub-system specific software
TMB
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

53. ATLAS is highly motivated, and on track, for first collisions in 2007
Conclusions
Many important milestones have been passed in the construction, pre-assembly,
integration and installation of the ATLAS detector components
Very major software, computing and physics preparation activities are underway as
well, using the Worldwide LHC Computing Grid (WLCG) for distributed computing
resources
Commissioning and planning for the early physics phases have started strongly
ATLAS is highly motivated, and on track,
for first collisions in 2007
(ATLAS expects to remain at the energy frontier of HEP for the next 10 – 15 years, and
the Collaboration has already set in place a coherent organization to evaluate and plan
for future upgrades in order to exploit future LHC machine high-luminosity upgrades)
(Informal news on ATLAS is available in the ATLAS eNews letter at
Physics at LHC, Cracow, July-2006, P. Jenni (CERN)

54. Physics at LHC, Cracow, 4-July-2006, P. Jenni (CERN)

55. Physics at LHC, Cracow, 4-July-2006, P. Jenni (CERN)