A superconducting accelerating test module for the European Spallation Neutron Source

In 1993 a multinational study group started to evaluate the feasibility for a next generation pulsed European Spallation Neutron Source (ESS). The beam is specified to have an average power of 5 MW at the target point with a repetition rate of 50 Hz. The final energy of the accelerated negative Hydrogen ions is 1334 MeV. The high energy part of the accelerator will consist of 168 5-cell cavities arranged in 7 groups in the beta range from 0.37 to 0.91. For the high beta cavities a superconducting option is planned [2]. A first superconducting accelerating module was designed and is currently under construction at ACCEL Instruments. The objective is to study the performance of the cavity and the cryomodule. The completed module will be delivered ready for cryogenic RF testing at Forschungszentrum Julich (FZJ) in the summer of this year. At present the cryogenic and RF supply for the test area is installed at FZJ. Besides the measurement of the cavity performance it is planned to study the influence of microphonics on the cavity and the RF stabilisation in pulsed mode operation. In a second step the RF equipment for high power coupler tests will be installed