(Video: Noemi Caraban Gonzales & Paola Catapano/CERN)

In the video above, Said Atieh of the Engineering department explains some of the unique challenges of welding on the Large Hadron Collider (LHC).

The interconnection regions between adjacent cryomagnets consist of a number of lines spanning from one machine element to another, and each line requires several welds.

With a radial clearance of only 45 millimetres, a machine called an automatic orbital welder closes three main busbars - lines whose main purpose is to conduct electricity. The machine makes two automatic welds to create a leak-tight assembly.

Technicians then check the leak rate between the cold mass of the magnet and the insulation vacuum. The acceptable value is so low that such a leak over 31 years would fill only a cubic centimetre.

Over 10,000 welds will be made on the LHC over the coming year.

See diagram: "The main 2013-14 LHC consolidations"