X-ray ultramicroscopy using integrated sample cells

Dachao Gao,Tim E Gureyev,Peter R Miller,Stephen W Wilkins,David J Parry,Eric Hanssen

doi:10.1364/oe.14.007889

Abstract

The X-ray ultramicroscope (XuM), based on using a scanning electron microscope as host, provides a new approach to X-ray projection microscopy. The right-angle-type integrated sample cells described here expand the capabilities of the XuM technique. The integrated sample cell combines a target, a spacer, a sample chamber, and an exit window in one physical unit, thereby simplifying the instrumentation and providing increased mechanical stability. The XuM imaging results presented here, obtained using such right-angle integrated sample cells, clearly demonstrate the ability to characterize very small features in objects, down to of order 100nm, including their use for dry, wet and even liquid samples.

Highlights

X-ray microscopy is a non-destructive technique that can provide information about internal structure of optically opaque objects
The right-angle-type integrated sample cells described here expand the capabilities of the X-ray ultramicroscope (XuM) technique
We are well outside the resolution level where radiation damage would be expected to be a problem for imaging of, say, frozen hydrated samples of biological cells [10]

Summary

Introduction

X-ray microscopy is a non-destructive technique that can provide information about internal structure of optically opaque objects. The ISC does not require special sample preparation such as coating or staining, and the sample may be imaged in its native state It has the advantage over the conventional XuM approach [6, 7] that few mechanical components are required and much greater mechanical stability is achievable. Our current XuM is based around a FEI XL-30 SFEG SEM [6, 7] It utilises a ‘rightangle’ geometry, that is, the X-ray source-detector axis is at right-angle to the electron beam. In order to demonstrate the ISC technique proposed in [8] and to be compatible with the current ‘right-angle’ geometry of the XuM, right-angle ISCs for high-resolution XuM imaging of very small objects including dry, wet and liquid samples have been developed. Two types of ISCs are described and XuM images collected using these ISCs are presented in this paper

Integrated sample cells

Experimental results and discussion

Infected Blood cells

Conclusions and future prospects