Short-range wakefields in an L-shaped corrugated structure

We present analytical and numerical studies of short-range wakefields in an L-shaped corrugated structure. This structure has variable streaking polarization and the quadrupole wakefield component is suppressed when the beam moves with equal distances to both plates. These features provide promising capability in multidimensional beam phase space diagnostic and fresh-slice applications. We first give zeroth-order analytical expressions of the longitudinal and the transverse wake functions using the conformal mapping method. Then we combine these results with the first-order approximate formulas of a single-plate structure to obtain more accurate analytical approximations of the wake functions of the L-shaped structure. In order to confirm the accuracy of the analytical model, we have developed a numerical method based on integral equations in the frequency domain for arbitrarily shaped waveguides with surface impedance boundary conditions.