Figure 1

(a) A diagram of the five-blade neutron interferometer. The neutron beam enters from the left and is coherently split by the first blade via Bragg diffraction, is diffracted by the following sequence of blades, and finally recombined and interferes at the fifth blade. After passing through the interferometer, the beam is captured by ${}^3\mathrm{He}$ detectors in the O and H beams. By moving cadmium shields up or down we can in situ select the three (MZ) or four (DFS) blade interferometer configuration. (b) A schematic top-view representation of the five-blade beam paths. The upper diagram represents the MZ setup. Here the beam block removes the two central beam paths and leaves the outer paths untouched. When we block the outer paths only we have the four-blade (DFS) setup, as shown in the lower diagram. (c) A schematic diagram of the neutron interferometer facilities at the National Institute of Standards and Technology. This facility has several vibration isolation stages to remove vibrations above 1 Hz. The primary stage consists of a 40-ton table that floats on actively controlled vibration isolation pads. The interferometer is enclosed in a temperature-controlled box. To test the robustness of the interferometers to mechanical vibrations we introduced vibrations by a motor with an off-center mass attached to the table.Reuse & Permissions

Figure 2

(a) Interferograms from the three-blade (MZ) interferometer without vibrations (open circles) and with 8 Hz vibrations (closed circles). We observe a complete loss of contrast with 8 Hz vibrations. (b) Interferograms from the four-blade (DFS) setup at the same conditions as in (a). Within experimental errors there is no loss of contrast from the added vibrations.Reuse & Permissions

Figure 3

Frequency dependence of the contrast with added mechanical vibrations. The dotted line with closed circles is for the three-blade (MZ) setup and straight line with open circles is for the four-blade (DFS) measurements. The inset shows a simulation for rotational vibrations.Reuse & Permissions