The cooling-water circulation equipment for the horn magnets at K2K experiment

摘要

The horn magnets for a long-baseline neutrino oscillation experiment (K2K) were installed in the neutrino beam line in February 1999 and have been operated since March 1999. In this experiment, the 44 observations were caught by the Super-Kamiokande detector until now. These two horn magnets were designed to be excited at pulsed high currents of up to 250 kA. The thermal load of the horn magnets is about 5.66 kJ and 0.86 kJ, respectively. Both horn magnets have a common system of a sprayed cooling system. The sprayed water becomes extremely radioactive due to flowing on the production target. Therefore, the water flow of two closed circulators was employed. Moreover, this equipment is considering the work that suppresses decline in the cooling efficiency by corrosion as oxidization.