KlyC. The 1D/1.5D large signal computer code for the klystron simulations. User manual.

Almost all the accurate and efficient 2D large-signal codes for the klystron simulations are proprietary and are not freely available to the wide klystron community. The klystron code KlyC1D/1.5D has been developed at CERN recently, as an attempt to bridge the gap between the fast, but approximate 1D models and the time/resource consuming PIC codes. Here the notation 1D/1.5D is related to the fact that in KlyC one can choose between a 1D or 2D map of the electric field (RF cavities and space charge), whilst the particle motion is one-dimensional. KlyC is available in the public domain. This manual should help the users to start with KlyC simulations.