Supermirror

A neutron supermirror is a highly polished surface used in connection with neutron beams.

Supermirrors are produced by depositing and polishing large numbers of layers of a reflecting substance, such as silicon, nickel, titanium or nickel/titanium composite, on a substrate. In this way, the critical angle of total reflection becomes ${\displaystyle n\cdot \theta _{c}}$, where ${\displaystyle n}$ is the number of layers and ${\displaystyle \theta _{c}}$ the angle of total reflection for a single layer.

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