Shape optimization of RF cavities: PhD progress report

by Ms Marija Kranjcevic

Thursday 19 Apr 2018, 13:00 → 14:00 Europe/Zurich

E13 (OHSA)

Abstract: Radio frequency (RF) cavities are elements in which an oscillating electric field is used to accelerate charged particles. The shape of an RF cavity determines the admissible eigenmodes, which can then be excited to obtain the accelerating electric field. The accelerating frequency, the shape of the corresponding eigenfield, as well as the properties of the entire spectrum, have a direct influence on the performance of the accelerator and should therefore be carefully tuned. With an appropriate parameterization of the cavities, this can be formulated as a multi-objective shape optimization problem. A possible optimization goal could be to minimize the peak electric field on the cavity surface and maximize the quality factor, with the constraint that the cavity shape must generate the desired accelerating frequency. In this presentation, a multi-objective evolutionary algorithm and a multi-objective gradient-based local search will be discussed and applied to the problem of optimizing the shape of the RF cavity of the Swiss Light Source (SLS), focusing in particular on the parallelization and the simulation results.