MEGAPIE at SINQ – The first liquid metal target driven by a megawatt class proton beam

The lead–bismuth liquid metal target MEGAPIE (MEGAwatt Pilot Experiment) was operated at the Swiss Spallation Neutron Source SINQ starting mid-August 2006, for a scheduled irradiation period until 21st of December 2006. The continuous (51 MHz) 590 MeV proton beam hitting the target reaches routinely an average current of ∼1300 μA, corresponding to a beam power 0.77 MW. This article illustrates the main features of the target and the ancillary systems specially needed for the liquid metal target operation. Further, the operational experiences made with this target during start-up and routine operation are summarized, besides the general performance highlighting new beam and target safety devices, and last but not least the neutronic efficiency in relation to the previously operated solid lead target.