Calculation of Eigenmodes in Superconducting Cavities on Ape–supercomputers Using a Software Interface to Mafia

To design modern accelerators a profound knowledge of eigenmodes of RF-cavities is required. For normal conducting as well as for superconducting cavities MAFIA is a well established tool to determine the eigenmodes by numerical means. However, the 3-dimensional treatment of multicell cavities lacks from available computer power on a usual high end workstation. Therefore the present approach uses a parallel SIMD supercomputer (APE-100) to compute the numerical expensive part of the MAFIA-algorithm. The system matrix, incorporating geometry and material information, is transfered to the APE-100 during a normal MAFIA-session using a command provided by the MAFIA toolkit (MTK). Then, on the APE-100 the lowest eigenvalues and their corresponding eigenvectors of the system matrix are determined by means of a conjugate gradient algorithm [3]. The result of the diagonalization procedure is then read back to the MAFIA host where further data analysis and visualization can be done.