Conceptual design of a 2kW cryogenic system for the neutrino superconducting beam line magnet system in the J-PARC 50GeV proton accelerator

摘要

An intense neutrino beam generated by the J-PARC 50 GeV proton accelerator is planned as a second generation long-baseline neutrino-oscillation experiment to study neutrino oscillation. A superconducting magnet system is required for the arc section of the beam line to bend the beam within the available space. One string of 14 cryostats containing two magnets is cooled by supercritical helium (SHE) flow re-cooled by two-phase helium (2PHe) counter flow. The string with a length of 150 m is set in the neutrino beam line tunnel 12m bellow the ground. Cooling flow is supplied by a helium cryogenic system with a capacity of 2 kW at 4.5. The conceptual design of the cryogenic system is described.