1. The ATLAS detector … … is composed of cylindrical layers: Tracking detector: Pixel, SCT, TRT (Solenoid magnetic field) Calorimeter: Liquid Argon, Tile Muon spectrometer: MDT, RPC, TGC, CSC (Toroid magnetic field).

2. We measure: time charge energy position Particle detection in ATLAS.

3. Trigger and Data acquisition Out of 1 billion proton collisions per second 100 000 have an interesting particularity detected by the dedicated electronics of the Trigger Level 1 For 3000 of them this is confirmed by dedicated processors of the Trigger Level 2 In the end only 200 interesting events are filtered out by 2000 multi-core PCs of the Trigger Level 3 and are finally recorded The particles create electric signals in the detector 1001010010100011001010010100011110010100101000111100101001010001111000 ATLAS writes the equivalent of 1 CD every 3 seconds This is a CD tower of of 7 km height every year. The signals are converted in digital data

4. 4 LHC Computing Grid. Tier-0 (CERN) Data recording First-pass reconstruction Data distribution Tier-1 (11 centres) Permanent storage Re-processing Analysis Tier-2 (>50 ATLAS centres) Simulation End-user analysis

5. The cavern …

6. ATLAS, H.Burckhart, CERN6 Excavation of Cavern UX (10/99).

7. ATLAS, H.Burckhart, CERN7 … the ceiling ….

8. 8ATLAS, H.Burckhart, CERN.

9. The detector …

10. The Globe … The Globe ….

11. Globe 27 m high, 40 m wide Atlas 25 m high, 46 m long … and ATLAS … and ATLAS Helfried Burckhart.

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21. The ATLAS members …

22. The ATLAS Collaboration 37 countries 169 institutions 2800 scientists (incl. 750 PhD students) The data are distributed all over the world.