KU Leuven, Kortrijk, Belgium
TEMF, TU Darmstadt, Darmstadt, Germany
Developing beam dynamics simulation tools using the moment method has advantages in terms of precision and efficiency when interests lie in average or rms dimensions of the beam, projected emittances or total energy. The moment method implemented in the V-Code solves the Vlasov equation by time integration, from an initial particle distribution represented by a discrete set of characteristic moments, accounting for all acting internal and external forces along the particle's path. The moment method delivers highly accurate beam dynamics results within a very small CPU time. This article proposes, illustrates and validates a new beam line element for a radiofrequency quadrupole (RFQ) for insertion in the V-Code. The focus will be on the RFQ cell structure, the electric field distribution and the insertion of the field distribution in the moment code.
KU Leuven, Kortrijk, Belgium
The dependence of the eigenfrequencies of a superconductive cavity on its geometry are represented by a stochastic response surface model. The model is constructed on the basis of both information on the eigenfrequencies as on their sensitivities with respect to the geometry. The eigenmodes are calculated using the 2D or 3D finite element method or finite integration technique. The stochastic representation does not only model uncertainties on the geometrical parameters but also inaccuracies of the eigenmode solvers, e.g. due to remeshing. Variations or optimisations of the geometry are carried out on the surrogate model. The model allows an efficient evaluation of microphoning and Lorentz detuning of accelerator cavities.
