WE3A6
PSI, Villigen PSI, Switzerland
One of the performance limiting factors of the next generation of XFELs is the generation of high brightness electron bunches. The current generation of S-band RF photoguns have reached their brightness limit. To continue to push brightness boundaries, a new photogun concept is needed. This contribution presents the design of a novel travelling-wave RF photogun that operates in the C-band regime. Beam dynamics simulations of this photogun illustrate that it can achieve a 5D beam brightness five times greater than the SwissFEL standing-wave gun. With the increased beam brightness, it is expected that intrabeam scattering (IBS) will play a more significant role through increasing the sliced energy spread (SES). Calculations of the IBS-induced SES illustrate that the increase in SES does not completely undo the brightness gain. We present the evolution of the SES over the injector and discuss how it influences the concept of optimising the beam brightness of an injector. Finally, this novel design also offers a path forward into higher repetition rate operation through its low attenuation, travelling-wave philosophy. This opens up the possibilities of operation into the kHz regime.
