CERN set for LHC start-up

By Leon Engelbrecht, ITWeb senior writer

Johannesburg, 08 Aug 2008

The European centre for nuclear research, known as CERN, plans to power up what is touted as the world's largest physics experiment, on 10 September.

The Large Hadron Collider (LHC) is now the coolest place in the universe, colder than even space, at a temperature of 1.9 degrees above absolute zero (-271^0C).

The LHC is a large particle collider, buried under the Franco-Swiss border, just outside Geneva, that generates charged sub-atoms to power a number of experiments. These are expected to generate petabytes of data that will be distributed worldwide for processing, including SA.

To handle and process this data flow, CERN - where the World Wide Web was created in 1989 - has in recent years pioneered grid computing.

The physical device is housed in a 27km-long super-cooled donut-shaped tunnel that also includes a number of detector arrays set up as independent experiments. One of these, the Atlas (A Toroidal LHC ApparatuS) experiment, is 46m long, 25m high, 25m wide and weighs 7 000t. It houses 100 million sensors and includes 1.2 million independent electronic channels.

The control of the collider and the detectors rely on an integrated service-oriented architecture, provided in part by Progress Software.

LHC project leader Lyn Evans says commissioning is already under way. Following the cool-down, completed at the end of July, the testing of the system's 1 600 superconducting magnets commenced.

The next phase in the process is synchronisation of the LHC with the Super Proton Synchrotron accelerator, which forms the last link in the LHC's injector chain.

Timing between the two machines has to be accurate to within a fraction of a nanosecond, says Evans.

A first synchronisation test is scheduled for this weekend of 9 August, with a second to follow in coming weeks.

"Tests will continue into September to ensure that the entire machine is ready to accelerate and collide beams at an energy of 5TeV (teraelectron Volt) per beam, the target energy for 2008. Force majeure notwithstanding, the LHC will see its first circulating beam on 10 September at the injection energy of 0.45TeV," Evans says.

Once stable circulating beams have been established, they will be brought into collision, and the final step will be to commission the LHC's acceleration system to boost the energy to 5TeV, "taking particle physics research to a new frontier", Evans notes.

Experiments at the LHC will allow physicists to jump ahead on a journey that started with British physicist Sir Isaac Newton and his description of gravity. CERN says gravity is ubiquitous since it acts on mass, "but so far science is unable to explain why particles have the masses they have".

Experiments such as Atlas may provide the answer. LHC experiments will also probe the mysterious dark matter and energy of the Universe. They will investigate the reason for nature's preference for matter over antimatter, probe matter as it existed close to the beginning of time and look for extra dimensions of space-time.

Another CERN spokesman, James Gillies, adds: "We know about 4% of the universe. The LHC might teach us about what the remaining 96% of the universe is made of..."