Upgrade of the accelerator for the laser undulator compact X-ray source (LUCX)

We have developed a compact X-ray source based on inverse Compton scattering of an electron beam and a laser pulse, which is stacked in an optical super-cavity, at the Laser Undulator Compact X-ray Source (LUCX) accelerator at KEK. The plan is to upgrade the accelerator and the super-cavity in order to increase the number of X-rays and to overcome the problems that have become clear in the experiments so far. A new RF gun with a high mode separation and a high Q value and a new klystron for the gun will be installed to provide good compensation with a high-intensity multi-bunch electron beam. A new optical super-cavity that consists of four mirrors is also being developed to increase the stacking power in the cavity and to reduce the laser size at the focal point. The final goal is to produce a long multi-bunch electron beam with 8000 bunches/train, 0.5 nC/bunch, and 5 MeV and to generate a soft X-ray with 6.5×107 photons/train after the upgrade. The upgrade plan is reported in this paper.