Ferracin, P Scandale, Walter Todesco, Ezio Wolf, R Modeling of random geometric errors in superconducting magnets with applications to the CERN Large Hadron Collider Phys. Rev. Spec. Top. Accel. Beams 122403 3 Estimates of random field-shape errors induced by cable mispositioning in superconducting magnets are presented and specific applications to the Large Hadron Collider (LHC) main dipoles and quadrupoles are extensively discussed. Numerical simulations obtained with Monte Carlo methods are compared to analytic estimates and are used to interpret the experimental data for the LHC dipole and quadrupole prototypes. The proposed approach can predict the effect of magnet tolerances on geometric components of random field-shape errors, and it is a useful tool to monitor the obtained tolerances during magnet production. eng 2000

http://documents.cern.ch/cgi-bin/setlink?base=generic&categ=public&id=cer-002237717; http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=aps&id=PhysRevSTAB.3.122403; http://cds.cern.ch/record/483940/files/PhysRevSTAB.3.122403.pdf; http://cds.cern.ch/record/483940/files/cer-002237717.pdf;

Imported from Invenio. Aleksa, Martin Russenschuck, Stephan Völlinger, Christine Parametric Quadrilateral Meshes for the Design and Optimization of Superconducting Magnets The program package ROXIE [1] has been developed at CERN for the design and optimization of the superconducting magnets for the LHC.The necessity of extremely uniform (coil dominated) fields in accelerator magnets requires very accurate methods of .eld computation. For this purpose a coupled boundary-element/ finite-element technique (BEM-FEM) is used [2]. Quadrilateral higher order finite-elements are used for the discretization of the iron domain.This is necessary for the accurate modeling of the iron contours and is favorable for 3D meshes. A new quadrilateral mesh generator using geometrically optimized domain decomposition which was developed at the University of Stuttgart, Germany [3] has been implemented into the ROXIE program providing fully automatic and user friendly mesh generation.The frequent application of mathematical optimization techniques requires parametric models which are set-up using a feature-based approach.The structure of the magnet cross-section can be modeled using parametric objects such as holes of different forms, elliptic, parabolic or hyperbolic arcs, notches, slots,etc. Investigations of the speed-up of the computations due to geometrically optimized meshes will be presented. For sensitivity analysis, point based morphing algorithms are applied to the generated mesh. eng 2000

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=lhc-project-report-448; http://cds.cern.ch/record/480812/files/lhc-project-report-448.pdf; http://cds.cern.ch/record/480812/files/lhc-project-report-448.ps.gz;

Imported from Invenio. Russenschuck, Stephan Aleksa, Martin Bazan, M Lucas, J Ramberger, S Völlinger, Christine Integrated Design of Superconducting Magnets with the CERN Field Computation Program ROXIE The program package ROXIE has been developed at CERN for the field computation of superconducting accelerator magnets and is used as an approach towards the integrated design of such magnets. It is also an example of fruitful international collaborations in software development.The integrated design of magnets includes feature based geometry generation, conceptual design using genetic optimization algorithms, optimization of the iron yoke (both in 2d and 3d) using deterministic methods, end-spacer design and inverse field calculation.The paper describes the version 8.0 of ROXIE which comprises an automatic mesh generator, an hysteresis model for the magnetization in superconducting filaments, the BEM-FEM coupling method for the 3d field calculation, a routine for the calculation of the peak temperature during a quench and neural network approximations of the objective function for the speed-up of optimization algorithms, amongst others.New results of the magnet design work for the LHC are given as examples. eng 2000

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=lhc-project-report-446; http://cds.cern.ch/record/480810/files/lhc-project-report-446.pdf; http://cds.cern.ch/record/480810/files/lhc-project-report-446.ps.gz;

Imported from Invenio.