Inauguration Symposium Held for LHC

摘要

The Large Hadron Collider (LHC) under construction at CERN will be the largest scientific instrument in the world (Figure 1). From 2008 onwards, it will bring into collision high-intensity beams of protons and ions, accelerated at very high energy, in order to probe the structure of matter at the Terascale, i.e. that of the quarks and gluons constitutive of nucleons, and to try and answer fundamental questions such as the asymmetry between matter and antimatter, the nature of "dark matter" and "dark energy" which constitute 96% of the mass-energy of the Universe, or the unification of gravity with the other forces. The LHC and its large particle detectors make intensive use of superconducting magnets and cryogenics, and the LHC helium cryogenic system is the largest and most complex in the world, with more than 160 kW equivalent at 4.5K (Figure 2) and 20 kW at 1.8K.