Spectroscopy Village

Figure 4: The new electron microscopy facility and I14 building under construction.

The Core EXAFS beamline B18 covers a wide energy range (2 to 35 keV), which means all elements heavier than phosphorus (P) in the periodic table can be studied. The experiments are run using a continuous energy scanning mechanism (QEXAFS), that allows a very efficient use of beamtime and is ideal for in situ experiments, so that time-dependent phenomena can be studied with a temporal resolution of a few seconds. In addition, as considerable value is added by combining techniques, provision has been made for wide angle X-ray diffraction studies to be incorporated into the beamline architecture. The combination of good flux and of effective detection systems allows collecting data on samples dilute to the mMol region. The instrument offers a variety of sample environments and the flexibility to integrate set-ups designed by the users. Hence, B18 is contributing to research programs across a wide range of scientific disciplines, e.g. solid state physics and materials, catalysis, chemistry, soft matter, surfaces and biomaterials.

I18 is the Microfocus Spectroscopy beamline where X-ray beams as small as 1/40th the width of a human hair are used to probe the chemistry of materials across the whole range of science. Much of the work on the beamline is within the geosciences and biosciences. An example of the crossover between these fields is the research into the biochemistry of fossils by teams led by Professors Phil Manning and Roy Wogelius of the University of Manchester, who have published four papers featuring I18 work investigating both animal and plant fossils in the last year.

The STFC-developed detector read-out electronics have been installed for the silicon drift detectors on I18. This system enables the two detectors to be used at about three times the count rate possible with their previous readout system. This allows the beamline to take better advantage of its high photon flux, and also now enables larger samples to be chemically mapped. The beamline has also upgraded its X-ray diffraction camera with a faster CMOS-based device, once again improving the speed of each measurement. This has proved particularly useful for 3D-imaging experiments, an area where the beamline has progressed considerably in the past year.

2014 has been a very challenging year for the Versatile X-ray Absorption Spectroscopy beamline, I20. The user programme on the Scanning branch had to be suspended when instabilities developed in the performance of the beamline’s four bounce monochromator. Significant efforts have been made to try to resolve the issues and restore the beamline to operational status. This is expected to happen before the end of 2015.

On a more positive note, work to bring the Dispersive branch of I20 into user operation has progressed well, with it seeing its first user experiment in April 2015. The modifications made to the polychromator have allowed the required spectral bandpass to be achieved. The ancillary sample environment and associated timing electronics and control software have been integrated into the beamline to permit the performance of time resolved experiments on microsecond and longer timescales. To take further advantage of the small focal spot delivered by the energy dispersive spectrometer, a diamond anvil cell has been purchased for the beamline to perform experiments at high pressure. To complete the suite of detectors that are required to cover the anticipated experimental programme, a FReLoN camera has been purchased from the European Synchrotron Radiation Facility (ESRF). This detector is particularly well suited to the study of chemical reactions on timescales slower than the millisecond.

I08-SXM is the Scanning X-ray Microscopy (SXM) beamline for morphological, elemental and chemical speciation on a broad range of organic-inorganic interactions in a 250-4400 eV photon energy range, which is unique for an SXM facility. I08-SXM offers versatile imaging modalities such as absorption, phase contrast and dark-field imaging as well as XRF and Near Edge X-Ray Absorption Fine Structure (NEXAFS) spectroscopies. A year ahead of the original project plan, the beamline welcomed first users in July 2014 and performed a series of successful experiments on environmental and earth sciences, material science, bio- and nanotechnology as well as medical applications. Although still in optimisation phase, the beamline already offers the full photon energy range to users with a spatial resolution better than 40 nm for some acquisition modes. A unique capability for a soft X-ray SXM, cryogenic cooling of radiation-sensitive specimen is available as standard for user experiments on the beamline. The I08 team reinforced their effort for establishing a second facility for soft X-ray diffraction imaging (ptychography), pushing the lateral resolution and chemical speciation to new frontiers not achievable with conventional SXM.

I14, the Hard X-ray Nanoprobe beamline, is 185 m long, designed to deliver nanoscale X-ray beams (<50 nm) for elemental, chemical and structural studies of a wide range of materials. Constructing a long beam requires optics hutches within the synchrotron building to condition the X-rays and an experimental endstation housed in an external building to focus the beam and provide the experimental facilities needed to conduct nanoscale studies.

The construction of the external building, which will house the beamline end station, support labs and new electron microscopy facilities, is now well underway with building completion due in September 2015. The I14 team has been busy this year completing the optics hutches and installing the mirrors, monochromator, diagnostics and slits that need to be in place before the X-ray beam is extended to the external building. Over the next year the optics hutch equipment will be extensively tested and commissioned while preparing to build and install the nanoprobe experimental end station. First light is expected in spring 2016 and first users in spring 2017.

The I21 beamline is a dedicated Inelastic X-ray Scattering (IXS) facility at Diamond, focusing on the soft X-ray energy range (250 – 3000 eV) with unprecedented energy resolving power (a few tens of thousands at 1 keV). The beamline will be 81 m long, with its end station and spectrometer accommodated in an external building adjacent to the Diamond ring. By studying the energy and momentum differences between the incident and the outgoing X-rays, users of I21 will be able to investigate the electronic, magnetic and lattice dynamics of novel materials of interest in both condensed matter physics and material science. Systems with strong electronic interactions and new functional materials such as Mott insulators, high-temperature superconductors, oxide heterostructures, catalysts, and carbon-based materials. The beamline construction has made significant progress, with the completion of the internal hutches in June 2014 and the completion of internal cabins and services in March 2015. First light is expected in February 2016 and I21 will welcome its first users in spring 2017.