BUTTING technology is being used to help scientists at CERN (Conseil Européen pour la Recherche Nucléaire, Geneva, Switzerland) find out more about anti-matter. Oval beam screen pipes and half shells are being supplied for use in CERN’s most ambitious project so far, the Large Hadron Collider (LHC). The LHC is a 27km-long underground circular tunnel in which protons and ions collide at high energy. The core of the LHC is a beam screen pipe measuring 48.5 x 38.9 x 1000/0.075 mm. This perforated oval pipe in the material grade Böhler P506, the inside of which is lined with the copper material OFE-Cu, was produced at BUTTING on a purpose-built fully automatic continuous production line. The production of 50,000 metres of pipe was finished at the end of 2004. In addition, smaller quantities of pipes were made in five different dimensions, with a wall thickness of 0.6/0.75 mm.
BUTTING is also producing more than 41,000 metres of half shells in AISI 316LN (1.4429) totalling about 3000 tons. These shells have an inside diameter of 550mm, a wall thickness of 10.1mm (+0.9/-0) and a length of 15,450 mm each. They are produced both in a concave and convex shape to form the jacket of the superconducting magnets. For the production of these shells, CERN had prescribed very tight dimensional tolerances. In addition, the stringent tolerances on form and position presented quite a challenge. A lot of effort was required to realize the geometry of the shells to meet the required tolerances. As the tunnel needs to be exactly round, it is necessary to control the prescribed minimal curvature of the shells already at production stage. BUTTING, in co-operation with the customer, was able to find acceptable solutions.
