Compact waveguide distribution with asymmetric shunt tees for the European XFEL

In the European X-ray FEL 32 superconducting cavities (4 cryomodules with 8 cavities per module) are connected to one 10 MW multibeam klystron through a waveguide distribution system. The XFEL tunnel has limited space for the waveguide system and therefore a new more compact waveguide distribution has been developed. The waveguide distribution is based on a binary cell which consists of two circulators connected to a shunt tee with integrated phase shifters. Four binary cells are combined by three asymmetric pretunable shunt tees. The asymmetric shunt tees allow to change the RF power for each pair of cavities and to reach the maximum cryomodule gradient. In this paper we will present the status of the waveguide distribution system and report on the development of the different new waveguide components.