Reflection High Energy Positron Diffraction from a Si(111) Surface

Abstract

This report details the first observation of reflection high energy positron diffraction. A 20 keV positron beam was irradiated onto a hydrogen-terminated Si(111) surface from the $[1\overline{1}0]$ and $[11\overline{2}]$ directions. The zeroth Laue zone consisting of a specular and diffraction spots with a shadow edge was clearly observed using a microchannel plate at relatively high glancing angles $(\ensuremath{\theta}>3.0\ifmmode^\circ\else\textdegree\fi{})$. The rocking curve of the specular spot showed the primary Bragg peak and the total reflection of positrons.