A new 3-D electromagnetic solver for the design of arbitrarily shaped accelerating cavities

We present a new algorithm well suited for the modal analysis of arbitrarily shaped cavities filled with a lossless, isotropic and homogeneous medium. The electric-wall condition is enforced on the field produced by an unknown current sheet, distributed over the cavity wall, and the resulting Electric Field Integral Equation (EFIE) is solved using the method of the moments (MM). Thanks to the special form of the kernel of the EFIE, the algebraic problem can be rearranged to yield the resonating frequencies and the associated currents as eigenvalues and eigenvectors of a standard linear eigenvalue problem. The algorithm yields all resonances up to the maximum frequency of interest by a single evaluation of the MM matrices. For this reason CPU times are reasonably short, even in finding many resonances of quite complicated cavities. The cavity shape is modelled using triangular patches and the code is interfaced with a commercial mechanical CAD