Design of a high duty cycle, asymmetric emittance RF photocathode injector for linear collider applications

One of the attractive features of the superconducting approach to linear collider design is that the transverse emittances demanded are much larger than in normal conducting schemes. For TESLA design parameters, the damping rings appear to be relatively large and expensive, and it is therefore of some interest to look into alternative sources. For electrons, a promising source candidate is an RF photocathode. In this paper, we present conceptual design work towards development of an asymmetric emittance RF photocathode source which can operate at the TESLA repetition rates and duty cycle, and is capable of emitting beams with the required emittances and charge per pulse