A differential time-of-flight spectrometer of very slow neutrons

A time-of-flight spectrometer of neutrons with energies of 0.05–2.50 μeV is described. This spectrometer has been tested by measuring the total and differential neutron cross sections for a number of materials—aluminum, copper, silicon, zirconium, polyethylene, 6 LiF, and fluoropolymers—that are essential for experiments in physics of ultracold neutrons.