Advanced Photon Source

A U.S. Department of Energy, Office of Science,
Office of Basic Energy Sciences national synchrotron x-ray research facility

 

Partner User Proposal Abstract

Short Proposal for Limited Scope Partnership User at the Advanced Photon Source; Dedicated Fresnel Coherent Diffractive Imaging Facility at 2-ID-B (PUP-74)

We propose here a Partner User Proposal to establish a novel x-ray imaging capability at APS that combines the advantage of scanning x-ray microscope (SXM) for extended specimens with the high-resolution imaging modality of coherent diffractive imaging (CDI). The key apparatus to be brought to the APS by this international partnership is a state-of-the-art end-station instrument being designed and constructed by Xradia, Inc and La Trobe University, worth ~US$1.5M, containing a full suite of interferometrically controlled in-vacuum stages that will allow high-precision nanometer scale positioning and scanning for CDI of extended nonperiodic specimens with 3D tomography capability. This instrument will be the first of its kind in the world and will substantially advance the state of coherent diffraction x-ray microscopy and enable new scientific applications in biological and materials sciences. We anticipate that launching this new capability, which could be the basis for a permanent facility at APS, will significantly benefit the user community and attract new users to APS. We propose to implement this new instrument at beamline 2-ID-B. The Major Partners behind this proposal have a long history of productive collaboration with the team at 2-ID-B and have, for the last few years, been developing a novel approach to coherent diffractive imaging in which the coherent illuminating wavefront contains a spherical curvature. This approach, called Fresnel Coherent Diffractive Imaging (FCDI), has the following characteristics that will be of value to the scientific program at 2-ID-B:

• reliable and unambiguous image reconstruction;
• an established spatial resolution of ~16nm, with expected sub-5nm resolution using the new instrument;
• a dose efficiency comparable to that of SXM; quantitative phase measurement;
• the ability to image any region within an extended sample with no need for exotic sample preparation; an experimental configuration that is essentially identical to that of scanning x-ray microscopy (SXM).

The last points are unique facets to this proposal as they enables the establishment of a system that offers both a powerful high-resolution imaging capability for extended objects, as well as a very high-quality facility for scanning x-ray microscopy in both transmission and fluorescence modes, providing the potential for the development of a novel combined imaging modality. The Australian Research Council Centre of Excellence for Coherent X-ray Science (CXS) has committed the appropriate funds to the construction and the implementation of this newly developed FCDI microscope. This PUP will see the establishment of this facility at 2-ID-B along with provision of support for visiting experimental groups. The PUP is backed by an outstanding international group of scientists who will work on both the further development of the imaging methodologies and also apply the methods to address many outstanding scientific questions.