A CW normal-conductive RF gun for free electron laser and energy recovery linac applications

Currently proposed energy recovery linac and high average power free electron laser projects require electron beam sources that can generate up to ∼ 1 nC bunch charges with less than 1 mm mrad normalized emittance at high repetition rates (greater than ∼ 1 MHz ). Proposed sources are based around either high voltage DC or microwave RF guns, each with its particular set of technological limits and system complications. We propose an approach for a gun fully based on mature RF and mechanical technology that greatly diminishes many of such complications. The concepts for such a source as well as the present RF and mechanical design are described. Simulations that demonstrate the beam quality preservation and transport capability of an injector scheme based on such a gun are also presented.