Reduced coherence in double-slit diffraction of neutrons

In diffraction experiments with particle beams, several effects lead to a fringe visibility reduction of the interference pattern. We theoretically describe the intensity one can measure in a double-slit setup and compare the results with the experimental data obtained with cold neutrons. Our conclusion is that for cold neutrons the fringe visibility reduction is due not to decoherence, but to initial incoherence.

Figure 1

Comparison between theoretical prediction derived here (solid line) and experimental data taken from [1] (solid circles) for neutron double-slit diffraction. (The unit of intensity is the intensity of the central maximum.)

Figure 2

Comparison between the theoretical prediction derived with our first model for the passage through the grating (solid line) and experimental data taken from [1] (solid circles). (The unit of intensity is the intensity of the central maximum.)