Realistic Models for RF Cavities

We present realistic models, including fringes, for several standing-wave modes in rf cavities. These models include a simple accelerating mode and a TM-110 (crab) mode. They are useful for the accurate computation of transfer maps% \footnote{D.T. Abell, ``Numerical computation of high-order transfer maps for rf cavities'', \emph{Phys. Rev. ST Accel. Beams} \textbf{9}, 052001, (2006).} as well as for constructing model fields that can be used for testing and comparing a variety of rf cavity codes.