The hard X‐ray undulator beamline for micro‐ and nanobeams – NanoMAX – will enable imaging applications exploring diffraction, scattering and fluorescence methods. A major consideration for the construction of NanoMAX is to utilize MAX IV’s exceptional low emittance, high brilliance and coherence properties of the x‐ray beam. This should make the NanoMAX beamline a flagship beamline for MAX IV showcasing the full potential of the ring and introducing a variety of new tools for many different research communities in Sweden, as also evidenced by the strong and broad support for the beamline.
X‐ray imaging approaching the low nanometer range is one of the most rapidly and strongly developing areas at all modern synchrotrons, e.g., ESRF, Petra3, APS, Soleil or NSLS II. A central reason is that applications of micro‐ and nanobeams can be found in all major natural science fields, such as materials science, life science, earth science, nanoscience, as well as in other fields of physics, chemistry and biology. In addition, modern 3rd generation synchrotrons are extremely well suited for this type of beamlines – in particular MAX IV. A unique quality of this new imaging toolbox is the opportunity for direct in‐situ, in‐vivo and in‐operando experiments exploring very challenging physical environments and giving direct correlation between structure and physical properties. It also allows 2D and 3D mapping of structure, strain and morphology within complex natural or man‐made structures. Finally, the unique properties of MAX IV should make coherent imaging techniques an interesting application at the NanoMAX beamline.
Many Swedish and international groups with different scientific backgrounds both with and without previous experience with synchrotron radiation have expressed interest in using NanoMAX for their research. This includes projects related to, for example, materials, IT, life science, and energy. Major groups are located at the Royal Institute of Technology (KTH), Uppsala University (UU), Swedish Agricultural University (SLU), Linköping University (LiU), Chalmers, Stockholm University (SU) and Lund University (LU), many with leading roles in identified Swedish strategic research areas, Linné centers and a variety of other strong research structures. In addition, researchers from Scandinavia and Western Europe, with strong experience in methods to be explored at NanoMAX, have expressed interest in the beamline. Amongst them are the researchers from the Technical University of Denmark –DTU and the University of Copenhagen. Scientists from the French national synchrotron facility ‐SOLEIL have expressed interest in close collaborations with NanoMAX.
Three main research topics have been identified:
Direct imaging inside complex heterostructures
A significant part of inorganic and materials chemistry is aimed at substances and materials that contain nano‐sized building blocks or particles. Nanofocus on a high brilliance synchrotron source will become an efficient tool to determine the internal arrangement of atoms and defects in nanostructures inside complex heterostructures. The high photon flux available will also allow time‐resolved measurements to study the dynamics of systems in evolution. Performing X‐ray fluorescence (XRF) raster scans will allow mapping localized compositional variations across individual nanostructures. Reciprocal space mapping will provide information about crystal structure and strain development. For in‐situ studies on an evolving system, a beam size of 50‐100 nm appears to be adequate. The exceptional beam coherence properties of the MAX IV source will provide new opportunities for coherent diffraction imaging experiments (CDI). Indeed, experiments on single gold clusters with a 200 nm beam [C.G. Schroer et al. Phys Rev Lett 101 090810 (2008)] have shown that an electron density projection can be obtained with about 5 nm spatial resolution. Ptychographic coherent diffraction raster techniques are well suited to the study of extended heterogeneous specimens and allow distributing of radiation dose for biological matter.
Bio functionalization, fibers, composites and life science
Nanobiology combines the tools, ideas and materials of nanoscience and biology; it addresses biological problems that can be studied and solved by methods from nanoscience and nanotechnology; it devises ways to construct molecular devices using biomacromolecules; it attempts to build molecular machines utilizing concepts seen in nature. The interest in basic biomass understanding is increasing rapidly due to the emergence of biofuels and biomaterials as important developments towards a sustainable society. Issues related to the onset of degradation and the evolution of the cellulose cells can be studied at NanoMAX. Sectioning of polymeric and biopolymeric materials into different directions can be used to extract structural information on specific morphological features (e.g. skin/core) in a raster scan experiment. Bio‐ and nano‐fluidics is an important area of growth. Indeed, the majority of proteins and in particular membrane proteins have until now not been crystallized and analyzed with atomic resolution by crystallographic techniques. The miniaturization of interaction volumes should allow reducing the timescale for studying protein conformational changes or biochemical reactions at reaction interfaces to the lower μs‐ and possible sub‐μs range. Microfluidic demonstration experiments have been performed at ESRF with no signs of radiation damage due to the continuous flow geometry. A very active area of research in Sweden is the study of biocompatibility of bio‐nano‐interfaces. One of the aims is developing nanostructured interfaces for cell adhesion and immobilization to allow further studies of physical and biochemical properties. The empirical approach of establishing biocompatibility by observation of cell growth could be complemented at the nano‐beamline at the level of single cells by raster XRF studies on the biochemistry of substrate‐cell interactions. High resolution XRF studies are of interest for a multitude of problems in environmental science such as the compositional variations of fly‐ash particles or the localization of nanoparticles in tissues and cells. It will offer fascinating possibilities for localizing nanoparticles acting as carriers for drugs or functional proteins within single cells.
In‐situ materials synthesis and processing
Modern materials science, the basis of many future and present day technologies, is to a large extent driven by the ability to reliably synthesize or process complex objects from microns down to a few hundred atoms often with novel properties and structures not found in the bulk. The formation, characterization and device incorporation of such structures are studied at virtually all Swedish universities with a very significant impact world‐wide. Here an especially intriguing possibility will be in‐ situ analysis of individual structures during the growth and processing by determining the evolution of structure, strain and chemistry with high resolution. Studies during high temperature annealing and curing of materials are also highly important for example for development or new alloys. Here also 3D imaging will be highly relevant. In many energy related systems such as solar cells or car catalysts, oxidation and reduction catalysts are required and, apart from being often in the form of nanoparticles, they are often combined with different kinds of nanostructured materials, such as nanostructured semiconductors or oxides. To investigate the structure of catalysts and the interaction of catalysts with nanostructured materials in solution and on surfaces, synchrotron radiation can provide unique insights and will play an important role in this research field. The imaging should be combined directly with photoelectrochemistry or gas phase reactions.