Design and realization of high-gradient C-band standing wave RF gun

To generate ultra-high brightness electron beams it is highly advantageous to use injectors based on Radio frequency photo-guns with very high cathode peak electric field. The current state of the art is the S-band (3 GHz) that allows to obtain cathode field at the level of 100 MV/m. To overcome the limits of this operating frequency a promising approach is to realize RF guns working at the C-band frequency (5712 MHz). In the context of the European I.FAST Project and INFN Commission V, a new C-band RF gun has been designed and realized at the INFN laboratories of Frascati. This RF gun has been fabricated with the brazing-free technology developed at the INFN and already applied to other electron sources. In this paper we present the design, the realization and the first tests performed on this prototype.