Experimental Investigation of Magnetohydrodynamics Effects in Molten Metals and Study of Homogeneity of Radioactive Mercury Amalgams

The high neutrino output demanded for a neutri no factory requests a high power proton beam interacting with a static target. The additional circumstances of limited space and long term stability ask for development of novel concepts for such types of targets. In our working group, part of the Neutri no Factory Working Group (NFWG) of CERN, we are investigating on the proton interaction with the mercury target. This is called the study of proton induced shocks in molten metal. In the US scheme for a neutrino factory the interaction between proton beam and the mercury jet target takes place inside a 20 Tesla solenoidal magnetic field, which serv es as a focusing device for the produced particles. This field of study is refe rred to as Magneto Hydrodynamics (MHD). The high power proton beam deposits a large amount of energy in the small volume of the target, which results in disruption. The aim is to establish experiments to study this phenomenon and to quantify the impact on the overall design of the target area. Shooting a high intensity proton beam into a steady merc ury target is to subsequently observe the effects of the thermal shock induced by th e energy deposition in the material. This experiment is part of a global study over high power proton target, which includes also the experiment performed at BNL [9] in spri ng 2001 to achieve more detailed results and to use the different proton energy of 2.2 GeV. Experiments are requested in order to deliver bench marks for nu merical simulations [34]. The second part of the work aimed to investigate magneto-hydro-dynamic effects occurring in the target area. Injecting the li quid metal target at a speed of more than 10 m/s into a 20 Tesla solenoidal magnetic fi eld causes forces on the liquid. The repulsion and pinching of the liquid jet will be stud ied experimentally. Numerical simulations will be compared with these results [35]. By the superposition of results achieved from these two experiments the feasibility of using a liquid metal target for a neutrino factory will be derived. The third part of the thesis work concerns the development of a technique for radioactive mercury handling and disposal. A final design of a neutrino factory will produce a certain amount of radioactive mercury, which might be destined for disposal/storage. After separation of radioactive merc ury by distillation the radioac tive part could be stored. Storage could only be handled after solidif ication of it. The procedure chosen for solidification is to produce amalgam from th e radioactive mercury. Small quantities for justification of the method ar e available from experiments at ISOLDE. As the quantity of used mercury will be relevant, the procedure developed will become the starting point of a production of industrial scale.