Genetic Algorithms with Niching for Conceptual Design Studies

The paper describes the use of genetic algorithms with the concept of niching for the conceptual design of superconducting magnets for the Large Hadron Collider, LHC at CERN. The method provides the designer with a number of possible solutions which can then be further optimized for field quality and manufacturability. Two 6 block dipole coils were found and proved to have advantages compared to the standard 5 block version

Genetic Algorithms for the Optimal Design of Superconducting Accelerator Magnets

The paper describes the use of genetic algorithms with the concept of niching for the optimal design of superconducting magnets for the Large Hadron Collider, LHC at CERN. The method provides the designer with a number of local optima which can be further examined with respect to objectives such as ease of coil winding, sensitivity to manufacturing tolerances and local electromagnetic force distribution. A 6 block dipole coil was found to have advantages compared to the standard 5 block version which was previously designed using deterministic optimization methods. Results were proven by a short model magnet recently built and tested at CERN

RF Breakdown in Drift Tube Linacs

The highest RF electric field in drift-tube linacs (DTLs) often occurs on the face of the first drift tube. Typically this drift tube contains a quadrupole focusing magnet whose fringing fields penetrate the face of the drift tube parallel to the RF electric fields in the accelerating gap. It has been shown that the threshold for RF breakdown in RF cavities may be reduced in the presence of a static magnetic field. This note offers a “rule of thumb” for picking the maximum “safe” surface electric field in DTLs based on these measurements

Strategy for allocating the MSI magnets and vacuum chambers

The known aperture limits in the MSI septa, together with the magnet and vacuum chamber geometry measurement, allows an optimisation of the installation regarding magnet and chamber allocation. The improvements are small but significant, of the order of 0.4 mm from allocation of the magnets and 0.7 mm from sorting and orienting the chambers; however, these gains are essentially for free, and should be implemented, since the apertures in these magnets are tight

Strategy for allocating the MSD magnets and vacuum chambers

An analogous strategy as applied for the MSI septum magnets allows an optimisation of the installation of the MSD septa regarding magnet and chamber allocation. Even if the gain in aperture is small, of the order of half a millimetre, it is not negligible and- being essentially for free - should nevertheless be implemented

Integrated design of superconducting accelerator magnets

This chapter introduces the main features of the ROXIE program which has been developed for the design of the superconducting magnets for the Large Hadron Collider (LHC) at CERN. The program combines numerical field calculation with a reduced vector-potential formulation, the application of vector-optimization methods, and the use of genetic as well as deterministic minimization algorithms. Together with the applied concept of features, the software is used as an approach towards integrated design of superconducting magnets. The main quadrupole magnet for the LHC, was chosen as an example for the integrated design process. (17 refs)