HZB, Berlin, Germany
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
Invited Talk: The computation of eigenmodes in chains of superconducting cavities with asymmetric couplers is a demanding problem. This problem typically requires the use of high-performance computers in combination with dedicated software packages. Alternatively, the eigenmodes of chains of superconducting cavities can be determined by the so-called State-Space Concatenation (SSC) approach that has been developed at the University of Rostock. SSC is based on the decomposition of the full chain into individual segments. Subsequently, the RF properties of every segment are described by reduced-order models. These reduced-order models are concatenated to a reduced-order model of the entire chain by means of algebraic side constraints arising from continuity conditions of the fields across the decomposition planes. The constructed reduced-order model describes the RF properties of the complete structure so that the field distributions, the coupling impedances and the external quality factors of the eigenmodes of the full cavity chain are available. In contrast to direct methods, SSC allows for the computation of the eigenmodes of cavity chains using desktop computers. The current contribution revises the scheme using the BESSY VSR cavity chain as an example. In addition, a comparison between a direct computation of a specific localized mode is described.
