To better understand the LHC and how the basic physics it studies can benefit society, join experts at swissnex San Francisco for LHC 101. Malika Meddahi, a physicist at CERN, describes what the collider is and how it works. Ian Hinchliffe, the US physics coordinator for the ATLAS detector, explains what scientists hope to discover from the LHC, including the illusive Higgs Boson particle. Elizabeth Clements, a senior science communicator at Fermilab, explains how the LHC and other particle accelerators contribute to innovation and therefore to the world economy in unexpected ways by advancing electronics, data storage, magnets, even tunneling technology

1. The Large Hadron Collider Malika Meddahi – CERN

2. Switzerland Lake Geneva LHC Accelerator (about 100m underground) SPS CERN CERN is the leading European institute for particle physics It is close to Geneva across the French Swiss border There are 20 CERN member states, 5 observer states, and many other states participating in research http://public.web.cern.ch/public/ CERN European Center for Nuclear Research

3. CERN accelerator complex CERN : produce many particles of different types and accelerate them to very high energies

4. The Large Hadron Collider LHC proton-proton collider 7 TeV per beam Circumference ~ 27 km 2 rings

6. Energy, mass and temperature 1 electron Volt (eV) ~ 1.8 x 10 -36 kg ~ 11.600 ºC 1 Tera electron Volt (TeV) ~ 10 16 ºC Comparison : Sun: outside temperature: 6’000 o C inside temperature: 15-20 10 6 o C

7. The Big Bang LHC : going back in time towards the big bang!

9. Fastest racetrack on the planet: Particles will race around the LHC ring at the speed of light, traveling at almost 300’000 km/s . In 1 second they will have travelled ~11’000 times the LHC ring. The fastest racetrack on the planet! 10 hours of LHC travel 100 times the distance between the earth and the sun!

11. ... to 7 TeV? LHC circular machine with energy gain per turn some MeV Synchrotron: circular accelerator and many passages in RF cavities

12. The accelerating cavity system … 4 cavities/module - 2 modules/beam - 16 MV (5.5 MV/m)

13. … installed in the LHC tunnel R.Schmidt - AAPT 2008

15. What makes LHC so special? The very large magnetic field Example: Magnetic field : Earth: 5x10 -5 T MRT: 2-3 T Accelerator Circumference Energy Magnetic field SPS 7 km 450 GeV 1.9 T LHC 109 km !! Too expensive… 7000 GeV 1.9 T LHC 7 km 7000 GeV 30 T ! Not possible LHC 27 km 7000 GeV 8-9 T Conventional magnets : NO Superconducting magnets: YES

18. What makes LHC so special? R.Schmidt - AAPT 2008 A total number of 1’232 dipole magnets, 15 m long, are required to close the 27’000 m long circle The number of magnets : ~ 10‘000

19. Tons to transport and install Installed in the tunnel: 50’000 t Transported over Europe: ~150’000 t

20. … .installation phase LHC dipole magnet lowered into the tunnel

21. Transport in the tunnel with an optical guided vehicle Magnet installation in the tunnel

22. Magnet installation in the tunnel

23. Checking and checking again…

24. Soudage des interconnexions cryogéniques Magnet interconnection brazing

25. 3 km long arc cryostat

26. Why is the LHC so special? The hottest spots in the galaxy: Collision of two beams of protons  generate temperature >100’000 hotter than the heart of the sun, concentrated within a minuscule space ( 0.020 mm diameter, 7 cm long ) Not 1 proton but 2808 bunches of 10 11 protons each!!! By contrast, the cryogenic distribution system which circulates super fluid helium around the accelerator ring, keeps the LHC at a super cool temperature of -271 C Extreme hot and cold!

27. The power stored in the LHC 360 MJoule: the energy stored in one LHC beam corresponds approximately to… 90 kg of TNT 8 litres of gasoline 15 kg of chocolate With so much stored energy.... ...HOW TO STOP THE BEAM? The energy of an 200 m long fast train at 155 km/hour corresponds to the energy of 360 MJoule stored in one LHC beam 20’000 tons British aircraft carrier at 12 knots

28. The only component that can stand a loss of the full beam is the beam dump block, all other components would be damaged about 8 m concrete shielding beam absorber (graphite) about 35 cm max 800 0 C How do we “kill” the LHC beam?