Spallation-driven Ultracold Neutron Sources: Concepts for a Next Generation Source

Abstract We present concepts for a next-generation, spallation-driven ultracold neutron source. Our source is based on a 40 liter volume of liquid He held at 1.6 K, with heat removed by “sub-cooled” He technology developed for the Large Hadron Collider's magnet systems. We report on neutronics modeling for two geometries which utilize well-vetted scattering and absorption data developed for the Lujan Center Mark-3 target, as well as promising moderator materials for the cold neutron “pre-moderator” for this source.