Ultra Cold Neutron Production with Medium Energy Proton Accelerater

UCN production in a medium-energy-proton beamline is proposed. UCNs are produced upon neutron-phonon collision in superfluid helium. Produced UCNs are vertically extracted from the superfluid helium to an experimental chamber for neutron β decay asymmetry or EDM experiment through a strong magnetic field of solenoids, which works as a siphon. UCNs are almost completely polarized upon passage through the magnetic siphon.