A setup with a mechanical chopper for monochromating neutrons and shortening a neutron flux from a pulsed neutron source

A spectrometric setup for studying the resonance structure of the total and partial neutron cross sections at energies below 10 keV has been created. The setup consists of two rotor-type mechanical neutron choppers with dc motors, an electronic system for stabilizing the rotation of rotors and phasing the moment of opening slits along a neutron beam with a neutron pulse, collimators, and neutron detectors. The angular rotational velocity of rotors changes from 0 to 6000 rpm, and their synchronization with the neutron pulse is provided with an accuracy of 10 μs at a minimum time of opening slits along the neutron beam of 20 μs. The setup is transported easily and can be placed on any neutron beam of the ИБР-2 fast pulsed reactor or other neutron sources. The values of the measured basic characteristics of the spectrometer agree with the calculated values within the experimental errors.