Focusing Elements and Design Considerations for a Scanning Helium Microscope (SHeM)

Abstract

We describe recent developments in the fabrication of an atom-optical mirror for focusing thermal helium atoms. A bent silicon crystal is, in principle, capable of high intensity, low aberration helium reflection; manipulation of the mirror's macrostructure minimizes optical aberrations in the device whilst chemical control over the mirror's microstructure ensures high intensity reflection. Incorporation of the atom mirror into a novel Scanning Helium Microscope (SHeM) is outlined, in the context of surface-structural studies. In particular, we refer to the expected operation, contrast mechanisms and resolution of such an instrument.