Abstract

Nearly all classical experiments known from light optics have been performed with matter waves as well. The most direct verifications of the wave nature stem from interference experiments. Different kinds of neutron interferometers based on wave-front and amplitude division have been tested in the past [1–4]. The perfect crystal interferometer — first tested in 1974 at our 250 kW TRIGA reactor — provides highest intensity and became the most frequently used neutron interferometer due to its wide beam separation and its universal availability for fundamental-, nuclear- and solid-state physics [5]. It represents a macroscopic quantum device with characteristic dimensions of several centimeters . The basis for this kind of neutron interferometry is provided by the undisturbed arrangement of atoms in a monolithic perfect silicon crystal [6,2]. An incident beam is split coherently at the first crystal plate, reflected at the middle plate and coherently superposed at the third plate