Moving Crystal Slow-Neutron Wavelength Analyser

Experimental proof that a moving single crystal can serve as a slow-neutron wavelength analyser of special features is presented. When the crystal moves with a velocity h/(2 md) (h-Planck constant, m-neutron mass, d-interplanar spacing) perpendicular to the diffracting plane and the analysed neutron beam is parallel to the diffracting plane, then neutrons of different wave-lengths contained in the incident beam are simultaneously diffracted under different reflection angles and recorded by a position-sensitive detector. Special features of this analysing system are briefly discussed.