Introduction to CERN F. Hahn / CERN PH-DT1 10. May 2007

A short history of CERN End of the 40’s: “Brain drain” towards the USA December 1949: Louis de Broglie proposes the creation of a European science laboratory. 1952: First Provisional “Conseil Européen pour la Recherche Nucléaire” Geneva site is selected. 29.9.1954: Organisation Européenne pour la Recherche Nucléaire 12 Member-states: B,CH, D, DK, F,GB, GR, I, N, NL, S, YU 40 ha in Meyrin (CH, GE) Building the first two machines: SC and PS F. Hahn / CERN PH-DT1 10. May 2007

CERN in 2007 490ha F, 112ha CH 20 member states: A, B, BU, CH, CK, D, DK, E, F, GB, GR, H, I, N, NL, PL, P,S, SF, SK. F. Hahn / CERN PH-DT1 10. May 2007

CERN a European Institute ? Particles research requires large installation for Accelerators and Detectors. Even the largest European countries could not afford to build a national laboratory for particle physics, that would have similar resources than CERN Today each country spends a small fraction of their gross national for CERN, allowing them to participate in the world’s most advanced physics experiments F. Hahn / CERN PH-DT1 10. May 2007

What is CERN ? CERN is a laboratory where scientists unite to study the building blocks of matter and the forces that hold them together. CERN exists primarily to provide scientists from Europe (and all the world) with the necessary tools. These are accelerators, which accelerate particles to almost the speed of light and detectors to make the particles visible. F. Hahn / CERN PH-DT1 10. May 2007

A few Numbers: Personnel: Scientific Users: 6775 Cost: Staff: 2635 dont: 74 Research physicist 957 applied physicist / engineers 898 technicians 474 clerks and administrative 233 hand workers Autres: 443 Fellows: 246 Scientific Associates: 397 Scientific Users: 6775 Distributed over 520 institutes and universities Belonging to 80 nationalities Cost: Annual budget: 1240 MCHF (2006) Electrical consumption: 700GWh/année F. Hahn / CERN PH-DT1 10. May 2007

The Building Blocks of Matter F. Hahn / CERN PH-DT1 10. May 2007

The “Standard Model” F. Hahn / CERN PH-DT1 10. May 2007

Four Interactions (Forces) Gravitation: Attraction between two masses Planetary Forces Electro-magnetic interaction: Cohesion des atoms Electricity, magnetism, chemistry Strong Force: Nuclear forces Origin of nuclear energy Weak Force: disintegration of neutron F. Hahn / CERN PH-DT1 10. May 2007

How to study Elementary Particles Elementary Particles are extremely small, to see them one needs special tools One needs accelerators, huge machines able to speed up particles to very high energies before colliding them into other particles. Around the points where the particle collisions occur, scientists build detectors which allow them to observe and study the collisions. Computer power F. Hahn / CERN PH-DT1 10. May 2007

The Tools Detectors Accelerators Computers F. Hahn / CERN PH-DT1 10. May 2007

Accelerators (1) Basic Components: A vacuum chamber surrounded by a long sequence of vacuum pumps, Radio-frequency cavities produce pulsed electric fields that accelerate charged particles Magnets: Dipole magnets are used to divert the beam onto a curved orbit Quadropole magnets are to focus the beam (like a lens) F. Hahn / CERN PH-DT1 10. May 2007

Accélérateurs [2] F. Hahn / CERN PH-DT1 10. May 2007

CERN’s machines F. Hahn / CERN PH-DT1 10. May 2007

Detectors Based on the principle of the interaction between charged particles and matter Identification of the resulting particles Measurement of their energy F. Hahn / CERN PH-DT1 10. May 2007

ALICE Detector F. Hahn / CERN PH-DT1 10. May 2007

Computers Theory computations, simulations , ... Controls for accelerator and detectors Data analysis F. Hahn / CERN PH-DT1 10. May 2007

Data Recording and Analysis Example: ATLAS Expected raw data written to tape: 200 events/sec = 320Mbytes/sec ( equivalent to 1 CD every 2 seconds, so 1’800 CD’s / hour That would make 7 km of CD stapled /year Data Analysis will be world Wide (GRID) Data will be exported from CERN to 10 computing centres with a rate of 10 Gbytes/sec. After processing data are distributed to 50 collaborating institutes. F. Hahn / CERN PH-DT1 10. May 2007

CERN at the leading edge of Technology CERN works in close collaboration with industries Examples: (non-exhaustive list) Superconductivity Cancer therapy, medical and industrial imaging radiation processing Electronics Measuring instruments, the WWW F. Hahn / CERN PH-DT1 10. May 2007