- Large Hadron Collider
The Large Hadron Collider
Large Hadron Collider (LHC) is the world's largest and highest-energy
particle accelerator. By smashing together sub-atomic particles at close
to the speed of light, it aims to recreate the conditions that existed
just a fraction of a second after the birth of the universe. In doing
so, it is expected to address some of the most fundamental questions
lies in a tunnel 27 kilometres (17 mi) in circumference, as much as
175 metres (574 ft) beneath the Franco-Swiss border near Geneva, Switzerland.
This synchrotron is designed to collide opposing particle beams of either
protons at an energy of 7 tera-electronvolts (7 TeV) per particle, or
lead nuclei at 574 TeV per nucleus. The term "hadron" refers
to particles composed of quarks.
was designed by the European Organisation for Nuclear Research (CERN) with
the intention of testing various predictions of high-energy physics,
including the existence of the hypothesised Higgs boson, and of the
large family of new particles predicted by supersymmetry. It was built
in collaboration with over 10,000 scientists and engineers from over
100 countries, as well as hundreds of universities and laboratories.
2008, the proton beams were successfully circulated in the main ring
of the LHC for the first time – but nine days later its operations were
halted due to a serious malfunction. In November 2009, they were successfully
circulated again, the first recorded proton-proton collisions occurring
three days later at the injection energy of 0.45 TeV per beam. After the
2009 winter shutdown, the LHC was restarted and the beam was ramped
up to half power, 3.5 TeV per beam (i.e. half its designed energy).
In March 2010, the first planned collisions took place between two 3.5
TeV beams – a new world record for the highest-energy particle
collisions. The LHC
will continue to operate at half power until 2015, when it reaches maximum
design capacity of 7 TeV.*
Initially, the experiment
sparked fear among the public that the collisions might produce a doomsday
scenario, involving microscopic black holes or hypothetical
particles known as strangelets. Two CERN-commissioned safety reviews
examined these concerns and concluded that the experiments at the LHC
presented no danger and that there was no reason for concern, a conclusion
endorsed by the American Physical Society.