X-ray Microscopy with the NSLS Soft X-ray Undulator

Abstract

Soft x-rays are attractive for microscopy because they tend to be less damaging to specimens than charged probes. In addition their interactions with specimens can result in element-specific information and the penetration depth is adjustable by choice of the beam energy. Resolution on the order of 50 nm has been demonstrated, and further improvements are anticipated. The experimental program at the NSLS X1A beamline is dedicated to soft x-ray microscopy. We are developing two types of instruments, both dependent on the remarkable brightness of the undulator source. One of these uses a Fresnel zone plate to focus the beam to a small size. This microprobe is used either to study biological specimens, or, in a different apparatus, to study surfaces by photoelectron microscopy. The other type of instrument makes use of x-rays diffracted by the specimen. In this category we are involved in the development of Gabor holography, Fourier transform holography, and in imaging by soft x-ray diffraction. © 1990 IOP Publishing Ltd.