The Centre for Advanced Electron Spin Resonance (CAESR) is a collaboration of researchers from the Oxford University Departments of Physics, Chemistry, Materials, Biochemistry, and Pathology. It was founded in 2006 with substantial support from EPSRC and the University to provide modern equipment and an academic focus for Oxford's multi-disciplinary research in electron spin resonance (ESR). CAESR has been spectacularly successful. It has nucleated a world-leading community of ESR spectroscopists in Oxford, and its stakeholders now extend well beyond the original group of co-applicants. It has established a national and international reputation as a centre of excellence in ESR. CAESR's scientific productivity and the research projects that it supports are now significantly constrained by two limitations of the existing equipment: (i) the availability of only two frequencies, 9.5 GHz (X-band) and 95 GHz (W-band); and (ii) a severe shortage of experimental capacity at the "work-horse" X-band frequency. We propose to reinforce CAESR's facilities with a Bruker Elexsys E580 X/Q-band pulsed electron spin resonance spectrometer. It will augment CAESR's facilities with a third frequency (Q-band, 35 GHz), and it will offer the experimental capacity needed by CAESR's growing community of participants. This instrument will significantly enhance CAESR's existing research projects and enable an exciting portfolio of new activities, covering a wide range of EPSRC priority areas and addressing each of EPSRC's Physics and Chemistry Grand Challenges. It will allow CAESR to apply ESR in innovative ways to new scientific problems and to lead methodological developments in ESR. The instrument has two features that will make it unique in the UK: high-power at Q-band, offering the shortest, highest-bandwidth pulses available; and an arbitrary waveform generator, allowing the direct synthesis of complex pulses for the first time in a turn-key ESR system. For 20% of the time, the instrument will be accessible to the wider UK ESR community through collaboration with the CAESR community, and via a contract with the EPSRC National EPR Facility based in Manchester. Young scientists from the Integrated Magnetic Resonance Centre for Doctoral Training (based in Warwick) will have the opportunity to explore the cutting-edge experimental capabilities offered by the arbitrary waveform generator and high-power amplifier incorporated in the new instrument, during annual training sessions at CAESR. The instrument's manufacturer, Bruker, seeks to strengthen links with CAESR by offering salary support for the Technical Manager. Through this interaction Bruker will receive first-hand feedback on instrument limitations, possible upgrades and new technical and methodological developments, and CAESR will receive preferential technical assistance in operating the instrumentation beyond its normal use-cases.

The work we propose in this research is to construct a MASER that can work at room temperature and in the Earth's magnetic field. The MASER (Microwave amplification by the stimulated emission of radiation) is in fact the forerunner of the LASER and was discovered around 50 years ago by Townes, Basov, and Prokhorov who shared the 1964 Nobel Prize in Physics for this work. A LASER can be thought of simply as MASER that works with higher frequency photons in the ultraviolet or visible light spectrum whereas a maser works at microwave frequencies. Both systems rely on a chemical species with an excited energy-level population being stimulated into lower energy levels, either by photons or collisions with other species. Photons are then emitted by the atom or molecule, in addition to the original photons that entered the system. The photons entering the system stimulate the emission of further photons of the same frequency, meaning that a strong beam of monochromatic radiation is produced. Originally the laser was seen as a good idea looking for an application. They were made in small numbers and at one point the US government decreed that every laser should be stamped with a number for military and security purposes - an idea that soon lost its appeal when the market potential for the quantities of the devices became apparent. Today lasers are made in their billions and have found their way into applications in all sectors of industry from DVD players to laser eye surgery. Masers on the other hand are used only in very specialised applications such as atomic clocks and as amplifiers in radiofrequency telescopes. Masers were responsible for the stunning images of the solar system sent by the Voyager spacecraft. So why have masers not been widely applied? There are two key reasons. First masers need cryogenic temperatures and this means the use of either cryogenic liquids or special fridges. Second, they need high magnetic fields and this means the use of bulky magnets that need high power and usually cooling with water, if an electromagnet, or with helium, if a superconducting magnet. This research is aimed at producing a maser that will operate at room temperature and in the earth's magnetic field. This is of course an extremely ambitious project but it is borne out of research in some of the materials that will be used in the project and these are the very high Q resonators. Work on high Q resonators has been carried out by the group for several years and now it appears that a solid state maser can be made using a high Q resonator and quite a low power. Our initial scouting experiments have shown that it is indeed possible to achieve masing at room temperature and earth's field in pulsed mode. The research that will be carried out will explore new materials that will miniaturise the maser and require very low power to achieve the threshold required for masing.

Are you familiar with piping icing onto cakes? Would you be surprised to know that our understanding of many of the flow processes taking place whilst you lay down beads are not actually fully understood? Wherever a fluid is "strained" - slid, squashed, or changed in shape, it responds with a force, or "stress". Studying fluid response to straining is known as "rheology". These forces influence how the rest of the fluid nearby moves, making it vital information to computationally model fluid flow problems: models that inform processing molten plastic into everyday objects, or our understanding of how a spider spins it's silk. Colloquially, rheology describes how "thick" a fluid is, but fluids can have hugely varying behaviours, all dependent on microscopic interactions occurring in the fluid. The flow and straining occurring through a piping nozzle is quite complicated. Near the nozzle walls, icing is mainly undergoing a "shearing" flow, where fluid layers slide over one another - this flow type is well understood and measurable in a lab. Near the centre, the fluid is experiencing "extension", where fluid packets are stretched in the flow direction and squashed in other directions. The nozzle tapering causes this. This extensional flow is less well understood or measureable, but in the last 50 years our understanding has improved, mainly because of the plastics industry. Between the location of the wall and the centre of the flow, simultaneous shear and extension exists - we call this a "kinematically mixed" flow. Not stirred, but mixed as in more than one type of straining present. To date, our only approach to validate models in this region has been to measure fluid velocity (for example) and see if our mathematical model predictions agree - models based on data from pure shear or extensional flows. Until now there hasn't been a way to unambiguously isolate and measure separate stresses within the middle of such flows, something that depends, via microscopic interactions in the fluid, on both shear and extension together. Making the situation even more complex, icing is an example of a "suspension", a class of fluids that display what is called a "yield" stress - it only flows when an applied stress exceeds some threshold. This allows icing to flow when the piping bag is squeezed, but means it resists flow under gravity after being deposited on a cake. The behaviour of suspensions under extension is particularly poorly understood at this time, versus what we know for plastics, let alone their behaviour under kinematically mixed flows. Not just icing cakes is affected. 3D printing cement to build novel houses is conceptually the same process, scaled up, and must handle much more stress without flowing. Depositing solder paste in electronics manufacture has similarities, as does processing graphene fibres into next-gen high performance materials. Plastics processing, a mixed flow, is not perfectly understood, and even lubricant flow in engine bearings is mixed. In fact, few flows are purely shear or extensional, and lacking a method to directly see how fluid stresses are responding under these mixed flows is detrimental to being able to accurately model and predict them. This impacts our ability to design industrial processes around it, and perhaps in the future, to use it to engineer new materials with exacting flow responses for specific applications. This fellowship will develop a new experimental technique that allows us to measure what shearing stress is occurring throughout a kinematically mixed flow by using magnetic resonance imaging - the same technology used in hospitals - and critically, makes whether a fluid is clear or opaque unimportant. With members of the modelling community interested in the project and a "round table" planned, benchmark experiments will be conducted to inform new fluid model development, and thereby facilitate a wide range of next generation materials and manufacturing processes.

NMR spectroscopy is arguably the most widely employed tool in materials, chemical and biomolecular research sciences for the study of atomic structure and behaviour. It has a uniquely powerful ability to probe the chemical structure at atomic level, combined with sensitivity to their motions and changes in chemical environment. The importance of NMR spectroscopy has been recognised by the UKRI's recent and largest-ever investment of £20 M in NMR spectroscopy in a UK-wide network of NMR spectroscopy facilities in 2018 which was matched by substantial provision of ongoing support through expert personnel and specialist infrastructure by the host institutions. Together these and previous significant capital investments made by UK research intensive universities, research councils and medical charities position the UK at the forefront of NMR technologies and will enable a very wide range of scientific investigations with a depth that was previously impossible. To ensure that we maximise the value of this capital investment, this proposal aims to establish a national NMR network in the physical and life sciences, Connect NMR UK, integrating the three main existing interdisciplinary communities (UK solid-state NMR; liquid-state, biological NMR; UK NMR managers group) and two learned societies (Royal Society of Chemistry NMR Discussion Group; Institute of Physics Magnetic Resonance Group) and connecting all of these NMR facilities through a central web portal, annual discussion forum, workshops and training scholarships. This will ensure we link the NMR solutions provided by the latest instrumentation and personnel, centred around the very- and ultra-high field NMR facilities, with the challenges being tackled by the UK's leading scientists. Providing these scientists with access to the cutting edge capabilities, sharing knowledge from the experts in these NMR facilities with the wider UK scientific community and exchanging best practice between the experts will ensure maximum value is obtained from the UKRI research council investment.

To support the development of challenging, difficult to manufacture products, increased reliance is placed on techniques to allow accurate dimensional measurement of parts and components. New measurement systems are needed that provide data quickly with higher levels of accuracy and precision than is currently possible. Currently high accuracy measurements are made using dedicated expensive instrumentation in temperature controlled labs. The wide range of measurement challenges mean there is no single instrument available to suit all needs. In fact, the range of lab based instrument systems required to meet the measurement needs of industry continues to grow. It includes techniques ranging from contact measurements made using a mechanical probe, to non-contact measurements which use light, lasers, or X-ray based measurement methods. The main drawback of these systems is that they are usually slow to set-up, and significant time is required to take measurements. This means that although they are very accurate they are less useful for the control and improvement of challenging manufacturing processes, where data must be collected and analysed quickly. Improved measurement systems are required which provide higher speed measurements, at lower cost, without compromising accuracy. Currently two approaches address this need. One approach uses on machine sensors to provide high-speed measurements, while the other approach is to position instruments closer to the manufacturing environment to reduce the time required to transfer work to the measurement lab. Both approaches have obvious benefits as they provide faster data; however, they are also less accurate as a result of the unwanted disturbances experienced on the factory floor. These limitations result in a trade-off: the user can either have high accuracy, or high speed measurement, but not both at once. The research undertaken within this Fellowship will develop a new way of collecting and effectively processing critical measurement data. Instead of a reliance on high accuracy instruments, this approach will provide a new way of thinking with respect to how measurement systems are designed and implemented. The goal will be to allow different types of lower accuracy data to be combined in a beneficial way. For example, computer simulations of a machine, product, and process will be combined with sensors that monitor environmental conditions. In addition sensors used to take high speed measurements of parts during the manufacturing process itself will be used. Through a collaborative process these data will be combined to provide fast high quality data. To verify and further improve the system a small quantity of accurate feedback data from high accuracy instruments in temperature controlled labs will be used. In effect the approach will be to combine slow accurate data, with fast less reliable data, to produce enhanced accuracy fast measurements. For example, if a batch of high precision components must be produced, the components must also have their geometry verified and corrected if required. On machine sensors may be used to verify geometry, but accuracy is limited due to environmental effects such as temperature and humidity. To compensate for these errors a collaborative measurement system will initially make measurements using both on-machine sensors as well as off-machine lab instruments. It will blend these data sets in addition to data from on-machine environmental monitoring sensors, and computer simulations to correct for errors and therefor enhance the accuracy of the measurements. The system will automatically adapt to changing environmental conditions by triggering the need for more lab-based data which will allow an improved error correction to be made. In this way the system will adapt and optimise the measurement process to suit the current manufacturing conditions.