Sorting Approach To Magnetic Random Errors

The problem of defining effective sorting strategies for the random errors of a magnetic lattice is analyzed. The final goal is to define a way of sorting the magnets in order to maximize the dynamic aperture. The proposed method is made up of three steps. First, one defines quality factors based on the perturbative tools of nonlinear maps and normal forms. Second, the best quality factor for the model considered is chosen through tracking analysis. Third, among some permutations of the magnets one chooses the one whose quality factor is better. The effectiveness a posteriori of the sorting strategy is checked through tracking. An application to sort the sextupolar errors of a cell lattice of the Large Hadron Collider is given. Submitted to Phys. Rev. E Geneva, Switzerland November 25, 1997 INFN, Sezione di Bologna, Via Irnerio 46, I-40126 Bologna. 1 INTRODUCTION One of the main issues in the construction of accelerators such as the CERN Large Hadron Collider (LHC) [1] is the effe..