Ultracold neutron turbine for the advanced neutron source

The paper describes a design for an ultracold neutron turbine source which has been developed for the planned Advanced Neutron Source at Oak Ridge. An “S”-shaped neutron guide transports very cold neutrons from a horizontal Cold Source to the turbine location. For the design neutron velocity of 40 m/s, this guide approaches the efficiency of a straight guide, while it filters strongly against neutrons with velocities above 60 m/s. The proposed turbine is designed for operation at a peripheral velocity of 20 m/s. This design speed, slower than that of existing turbines, has been chosen to minimize the effect of the circular turbine motion. The lower speed, coupled with the use of 58Ni as the turbine blade material, allows a significant increase in performance with fewer blades.