Some aspects of a time-domain neutron optics experiment

We report on recent progress in the observation of time-dependent matter wave optics with very cold neutrons (VCN). We have performed an experiment where a VCN beam was amplitude modulated by a high-frequency chopper. The resulting diffraction in time was measured with a special time-of-flight spectrometer that achieving an energy resolution of 22 neV. The measured spectra of different cases are discussed qualitatively.