New experimental test of dispersion law for very slow neutrons

The results of an experiment on transmitting UCN through a rotating disc made of silicon single crystal are reported. They demonstrate that the transmission of the sample remains constant if it moves parallel to its surface. The range of neutron velocities in the system of reference associated with the sample is 6-38 m/s. It is found that the real and imaginary parts of the effective potential are constant to within 3×10−3.