The MERIT High-Power Target Experiment at the CERN PS.

The MERIT experiment was designed as a proof-of-principle test of a target system based on a free mercury jet inside a 15-T solenoid that is capable of sustaining proton beam powers of up to 4 MW. The experiment was run at CERN in the fall of 2007. We describe the results of the tests and their implications. Plans are being discussed for possible future machines which can deliver proton beams with multi-MW beam powers. A prominent application for these powerful beams will be to produce intense secondary beams suitable for investigating important physics issues. Examples include investigations of rare decay processes and neutrino oscillations. The Neutrino Factory and Muon Collider Collaboration [1] has proposed a target system [2, 3] which will be capable of supporting proton beam powers of 4 MW with the purpose of producing and collecting intense muon beams for eventual use in storage rings. The core of this proposed target system consists of a high-Z, free-flowing liquid mercury jet which intercepts the proton beam within the confines of a high-field (15-20 T) solenoid. An important attribute of this system is that the liquid jet target can be replaced for subsequent proton pulses. The experiment described in this paper was designed to provide a proof-of-principle demonstration of this concept. Preparations for this experiment have been previously reported [4].