Electron microscopes allow imaging and spectroscopy at resolution up to and including atomic resolution, and are key tools for materials characterisation. The highest spatial resolutions are found in the transmission electron microscope (TEM), which makes use of a very thin samples (nanometres or 10s of nanometres thickness) to minimise beam spreading. The term "TEM", actually refers to a range of experimental techniques, including diffraction contrast imaging, high-resolution TEM (HRTEM), scanning TEM (STEM), energy-dispersive X-ray (EDX) spectroscopy mapping and electron energy-loss spectroscopy (EELS). The aim of the current proposal is to procure a Versatile, high-throughput, Analytical TEM (VATEM) at the University of Oxford. The aim of the instrument is that it should be versatile and therefore able to address the widest possible range of materials science problems; it should be high-throughput maximising the science delivery; and it should be relatively easy to use to enable researchers to experience the capabilities of TEM methods and to develop expertise in the field. It will be accessible to researchers ranging from undergraduates performing research projects to experienced academics. The UK has long been a world-leader in TEM method development and application, with substantial investment in world-leading capabilities such as those at SuperSTEM (Daresbury) and ePSIC (Diamond Light Source) and the Rosalind Franklin Institute which provide specific, high-level capabilities. Such facilities are only sustainable with a supporting infrastructure of instruments located at university centres of excellence. The instrument proposed here will form an important part of that infrastructure supporting regional and national research. The VATEM has been specified to study the widest possible range of samples. The portfolio of science that the instrument will address is exemplified in this proposal in the fields of materials for energy storage and conversion, materials for nuclear energy and nanomaterials, but the potential breadth of application is much greater than this. Materials critical for applications in energy storage, photovoltaic, nuclear, catalytic, degradation resistant and semiconductor devices all have key properties controlled by their structure and chemistry at the nanoscale. The imaging and spectroscopy methods available in a TEM can be used to determine structure and chemistry. There are, however, a number of challenges. Many such materials are either air-sensitive, electron-beam sensitive, or both. Developments in MEMS technology further allows nanoscale structure and composition measurements under a variety of environments including cooling, heating, gases, anaerobic, liquids, optical, electrical and mechanical stimuli. The instrument has been designed to address these challenges. The VATEM will be available researchers national and internationally who can demonstrate that the instruments capability will be meet a need in their research.

Internationally leading science requires experimental facilities with state-of-the-art equipment. Advanced materials are a key driver of technological innovation, with widespread benefits for both science and society. In this project, we aim to refresh four facilities with impact across Physics, Electronics, Chemistry and Biology in order to enhance our capability in this area, with maximum usage across the University of York and beyond. We will install new physical and chemical characterisation systems to support a range of challenging new applications, for example, state of the art thin film growth capabilities, and biologically-inspired sensor technologies. Using these new facilities, we will achieve four major milestones for next-generation materials development: 1. Refresh thin film growth capabilities in order to develop next generation materials. 2. Renew electron microscopy facilities to facilitate high spatial resolution mapping of next generation materials. 3. Extend and refresh a capability in molecular characterisation to underpin multidisciplinary activities spanning the physical and life sciences. 4. Refresh, complement and extend the capabilities of the York Centre of Excellence in Mass Spectrometry (CoEMS) by addition of a high-performance Orbitrap Fusion instrument. Through this proposal we will invest in state-of-the-art equipment that will enable us to create, analyse and understand new materials and use them to develop innovative interdisciplinary technologies within the university and with outside collaborators, including key industrial partners such as JEOL and Seagate.

Genomic and proteomic programmes increasingly drive our understanding of complex biological systems; advances in protein science allow us to understand protein form and function in ever increasing detail whilst nanotechnology research programmes are developing tools to study and manipulate systems on the length scale of 1-100nm. The current 'blind spot' is our inability to combine genomic and proteomic data with understandings of molecular mechanism and biochemical pathways in living systems. For instance, we may know the atomic structure of a protein, understand its protein or ligand interactions, how and where it assembles into multi-component structures within the cell. However, we are unable to image any of these processes directly in living cells with the necessary resolution to give a complete and satisfactory understanding of how things work. Recent forums of leading microscopists both in Europe and the UK have highlighted this issue and also the pressing needs to achieve higher resolution multicolour live cell microscopy. While new optical techniques are constantly evolving there still remains a critical gap between what is possible using electron sources and optically based methods. To meet this challenge we propose the development of our novel probes that will eventually result in a live cell, multicolour/component imaging within an Electron Microscope, making an apparent Fluorescence electron microscope (FEM). By combining recent technological advances in both optical and electron imaging with the development of our novel luminescent probes, we believe that this approach will create a technology that will far surpass any other known technique currently being developed and provide the step change required in microscopy to start true multicolour sub-light resolution imaging with few constraints and address this major limitation in biology. This would be a ground-breaking advance in biological imaging. We recognised that any new technology trying to enable sub-light/diffraction limited nanometre resolution imaging is limited by currently available fluorescent/luminescent probes that have all been designed for photoluminescent imaging. Our approach is to encapsulate, or chemically passivate, specially engineered nano-sized (in the region of 10nm) cathodoluminescent materials such as the material used for P43 (in colour TV screen phosphors) for cell labelling. These probes will have the added advantage that they will also be suitable for standard photon excitation and exhibit far better properties compared to most other fluorochromes due to their high electron beam and photo-stability, very narrow emission peaks and inert nature. Taking the advantage of conventional optical microscopy and the use of different luminescent probes to study multiple cellular components in a live environment and the resolution that can be achieved using a scanning electron beam, we will remove the current 'blind spot' in studying living systems. This will have a far-reaching impact on biological and medical research with the elucidation of fine detailed particle maps and the ability to study receptor organisation and interactions. Such interactions are known to play key roles in cell signalling, recognition and other vital cellular functions that are critical for healthy cell function and disease, yet little is understood due to our current inability to visualise live samples. As well as the biological applications, we believe our new luminescent probe technology will impact widely on many other fields, such as polymer research, surface science, micro and nanotechnology. Our probes and FEM will therefore have the widest possible application across many academic and industrial disciplines.

This research proposal is about new investigations to be carried out at York concerned with the physics and applications of a very recent development, namely the controlled creation of electron vortex (EV) beams. EV beams are a brand new type of electron beams which differ from common electron beams in that they are endowed with a twisting (vortex) property vaguely akin to a tornado vortex. They bear resemblance to optical vortices (OVs), which have been much researched over the last two decades or so. OVs have found applications in optical tweezers and spanners and have other potential applications as, for example, in quantum information processing. Associated with the twisting property in both OVs and EVs is a physical property called orbital angular momentum (OAM). However, EVs differ significantly from OVs in that an electron carries electric charge and mass and possesses another intrinsic twisting property, called spin, which can be vaguely visualised as a rotation about its own axis. Furthermore, as electrons also possess wave properties, their wavelength is much smaller than that of visible light. It is this feature that makes them potentially superior in their ability as EVs to enable much better images in an electron microscope to be taken than currently possible. It is also this same property that makes an EV an excellent probe of tiny matter at the sub-nanoscale and EVs in general are expected to be excellent probes of matter at the individual molecular and atomic levels. The electron spin has been utilised in probing the properties of magnetic materials, but the orbital angular momentum content of EV beams presents new properties. The electron orbital motion relative to a nucleus has been vital in understanding the electronic motion within atoms and molecules, but, until recently, has not been considered to be a property normally associated with electron beams such as those existing inside cathode ray tubes and in electron microscopes. This proposal aims to take advantage of the recent technological advance of EVs to explore the extensive properties of such electron beams and to carry out investigations in both fundamental studies and practical applications. Specifically, we will develop ways to fabricate filters and convertors to generate various kinds of EV beams inside electron microscopes and to study their potential in fundamental research and ways of tailoring them for practical applications. We plan to investigate a number of many, as yet, unexplored phenomena associated with the processes of the quantized transfer of orbital angular momentum between the orbital angular motions of the EV beam and that of the sample to explore the chiral specific properties of materials, such as magnetic and plasmonic transitions. We will explore the phenomena of electron vortices residing in the phase structure within the beam to develop new electron microscopic methods for revealing phase structures such as biological molecules. We will exploit the interesting 'diffraction-free' effect of the Bessel beams, i.e. pencil-like narrow beams, to develop 3D scanning microscopy tomography of nanostructures with better resolutions. We will also explore the complex structured intensities of the EV beams to develop efficient atom trapping and nanolithographic tools.

The central issues of our current research are the cellular mechanisms that contribute to the function and modification of individual central synapses. For over 20 years we have utilised high-resolution transmission electron microscopy (TEM) and 3-dimensional (3-D) reconstructions of neural ultrastructure in the hippocampus of the central nervous system, mainly of rodents, following use a several learning and plasticity paradigms. The TEM methods used have advanced considerably in recent years with application of computer controlled stage positioning, while the use of film to capture images has been supplanted via application of high resolution digital cameras on electron microscopes. This has enabled production of digital images where the resolution is at least the equal of film derived prints and thus has facilitated rapid acquisition of a much greater number of images. However, while advances in computing power have enabled more rapid processing of images, the process of making 3-D reconstructions remains a very time intensive process with little automation of the processes being feasible. Alternative approaches in the ability to study connections between synapses and spines have been suggested by optical advances in at light microscope level but because of resolution limitations these do not permit with any precision, measurements of the contacts between nerve cells - synapses. Scanning electron microscopes (SEMs) are much more suited to automation than TEMs and can easily work with much larger samples. It has already been shown that field emission (FE)-SEMs working in back scattered electron (BSE) imaging mode with conventionally prepared and stained TEM sections can produce excellent resolution and contrast images, comparable to TEM images. Our strategy will therefore be to develop a novel method to make montages, and reconstructions of a large area of serial sections of mouse or rat hippocampal tissue. Our study will be a collaborative effort using state of the art facilities at JEOL UK (SEM and TEM manufacturers). The key of the new method to make such a gigantic montage is the automatic image acquisition system with very accurate stage control of the SEM (in position terms). Software would automatically acquire multiple images from each of a number of sections. Images from each section can be montaged to form single, large montages of each section, which can then be combined into a large-scale 3-D reconstruction. We believe that this methodology can then be applied to our regular studies of synaptic and dendritic plasticity.