GENEVA, June 15 (Xinhua) -- CERN, the European Organization for Nuclear Research, started on Friday a major upgrading build-up of the world's largest particle smasher, the Large Hadron Collider (LHC), aiming to churn out 10 times more data and help unlock the secrets of physics in the decades to come.
The start of the civil-engineering work for the High-Luminosity LHC (HL-LHC) would become a new milestone in CERN's history, which is expected to considerably improve the performance of the LHC by 2026, by increasing the number of collisions in the large experiments and thus boosting the probability of the discovery of new physics phenomena.
The LHC started colliding particles in 2010. Inside the 27-km LHC ring, bunches of protons travel at almost the speed of light and collide at four interaction points. These collisions generate new particles, which are measured by detectors surrounding the interaction points. By analyzing these collisions, physicists from all over the world are deepening our understanding of the laws of nature.
While the LHC is able to produce up to 1 billion proton-proton collisions per second, the HL-LHC will increase this number which is referred to by physicists as "luminosity," by a factor of between five and seven, allowing about 10 times more data to be accumulated between 2026 and 2036.
That means physicists will be able to investigate rare phenomena and make more accurate measurements. For example, the LHC allowed physicists to unearth the Higgs boson in 2012, thereby making great progress in understanding how particles acquire their mass. The HL-LHC upgrade will allow the Higgs boson's properties to be defined more accurately, and to measure with increased precision how it is produced, how it decays and how it interacts with other particles.
The secret to increasing the collision rate is to squeeze the particle beam at the interaction points so that the probability of proton-proton collisions increases. To achieve this, the HL-LHC requires about 130 new magnets, in particular 24 new superconducting focusing quadrupoles to focus the beam and four superconducting dipoles.
Both the quadrupoles and dipoles reach a field of about 11.5 tesla, as compared to the 8.3 tesla dipoles currently in use in the LHC. Sixteen brand-new "crab cavities" will also be installed to maximize the overlap of the proton bunches at the collision points. Their function is to tilt the bunches so that they appear to move sideways, just like a crab.
Beginning in November 2011, the HL-LHC project, as an international endeavor, involves 29 institutes from 13 countries. It will include major civil-engineering work at two main sites in Switzerland and France respectively, during which more than 1.2 km of the current 27-km LHC will need to be replaced with many new high-technology components such as magnets, collimators and radiofrequency cavities.
