Abstract
A plane mirror rotatable about two orthogonal axes has been developed for imaging low‐energy electron diffraction(LEED) spots into a photometer tube. The mirror is driven by stepping motors and controlled by a PDP 11 computer. Using a sequence of primary‐beam energy values in steps of 2 eV the acquistion time for the normalized intensity data from one diffraction beam between 30–200 eV takes approximately 10 s.