Coil end optimization for the LHC main dipole

The Large Hadron Collider (LHC) requires twin aperture superconducting dipoles of 8.65 T dipole field to guide the proton beams in the existing LEP tunnel. Special attention is paid to the optimization of the coil ends of these dipole magnets as these regions have been the source of training quenches. The objectives for the optimization are small internal stress in the cable due to coil winding, a low integrated multipole content, low enhancement of the peak field in the coil and a homogeneous Lorentz force distribution. The paper describes some features of the computer program ROXIE, which has been developed for these purposes and gives results for the optimized dipole coil end