Recent developments towards CW operation of the superconducting XFEL accelerator

• Elmar Vogel (DESY MSL)

A future upgrade of the European XFEL (E-XFEL) foresees an additional CW operation mode. It will increase the flexibility in the photon beam time structure but provide lower beam energy to the undulators than the pulsed operation mode which will be kept. The talk will give an overview on the present development status of the components and items concerned: power sources, power switches, rf control, modules and cavities, power couplers, cryogenics, a new and second photoinjector operating CW, 3rd harmonic RF and beam dynamics studies.

R&D of CBPM prototype for SHINE

• Yongbin Leng (SXFEL and SHINE )

The Shanghai high repetition rate XFEL and extreme light facility (SHINE) under construction is designed as one of the most advanced FEL facilities in the world, which will produce coherent x-rays with wavelengths from 0.05 to 3nm and maximum repetition rate of 1MHz. In order to achieve precise, stable alignment of the electron and photo beams in the undulator, the prototype of the cavity beam position monitors (CBPM) including C-band and X-band have been designed and fabricated for the SHINE. And the requirement of the transverse position resolution is better than 200 nm for a single bunch of 100 pC at the dynamic range of ±100 μm. In this paper, we present the design of the cavity with high loaded Q and the RF front-end with low noise-figure, adjustable gain, single-stage down-conversion and phase-locked with reference clock, and also described the structure and specifications of the home-made data acquisition (DAQ) system. The construction of the experiment platform and preliminary measurement result with beam at Shanghai Soft X-ray FEL facility (SXFEL) will be addressed as well.