AVS 57th International Symposium & Exhibition
    In Situ Microscopy and Spectroscopy Topical Conference Wednesday Sessions
       Session IS+BI+AS-WeA

Invited Paper IS+BI+AS-WeA7
Biological Imaging with Coherent X-rays: The Lens-less Approach to High Resolution

Wednesday, October 20, 2010, 4:00 pm, Room Acoma

Session: In Situ Microscopy/Spectroscopy – Biological Interfaces
Presenter: A. Beerlink, Universität Göttingen, Germany
Correspondent: Click to Email

Understanding molecular functions in complex environments such as biological cells or novel composite materials are a prerequisite for the advancement of nano and biomedical sciences. They require a combination of high spatial resolution, quantitative contrast and

full compatibility with environmental conditions, such as aequous media. To this end, the potential of x-ray imaging is not yet fully developed, but currently undergoes rapid progress. While classical x-ray microscopy based on Fresnel zone plates has matured and provides useful structural information in a growing range of applications, this technique is severely limited by the nanostructuring process of the lenses. In

recent years, novel lens-less approaches for imaging have emerged, where the object functions are reconstructed from the measured intensities

either in the far-field regime, or under near-field conditions (propagation imaging). We present experiments using x-ray quasi point sources to illuminate the sample in combination with digital recording of the resulting diffraction patterns. One focus is the applicability towards biological samples, for which the imaging properties of the different coherent microscopy approaches will be compared. In this context, recent results obtained with ultrabright femtosecond pulses provided by the free electron laser FLASH will be presented and accessible information complementary to synchrotron imaging will be discussed.