A5077149325- Advanced X-ray Imaging Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced X-ray and CT Imaging
- Advanced Electron Microscopy Techniques and Applications
- Electron and X-Ray Spectroscopy Techniques
- Advancements in Photolithography Techniques
- Medical Imaging Techniques and Applications
- Laser Design and Applications
- Laser-Matter Interactions and Applications
- Dental materials and restorations
- Laser-induced spectroscopy and plasma
- Atomic and Molecular Physics
- Advanced Surface Polishing Techniques
- Advanced MRI Techniques and Applications
- Dental Radiography and Imaging
- Optical Coatings and Gratings
- Laser-Plasma Interactions and Diagnostics
- Enzyme Structure and Function
- Radiomics and Machine Learning in Medical Imaging
- Radiation Dose and Imaging
- Integrated Circuits and Semiconductor Failure Analysis
- Forensic Anthropology and Bioarchaeology Studies
- Crystallography and Radiation Phenomena
- Near-Field Optical Microscopy
- Particle Accelerators and Free-Electron Lasers
University Of Bristol Dental Hospital
2024
King's College London
1992-2022
Guy's Hospital
2021-2022
University Dental Hospital on Cardiff University
2018
AREA Science Park
2011
University of Cambridge
1997-1998
King's College Hospital
1989-1993
The King's College
1991
University of London
1982-1988
King's College - North Carolina
1988
Exploring the dynamics of matter driven to extreme non-equilibrium states by an intense ultrashort X-ray pulse is becoming reality, thanks advent free-electron laser technology that allows development different schemes for probing response at variable time delay with a second pulse. Here we report generation two-colour ultraviolet pulses controlled wavelengths, intensity and timing seeding high-gain harmonic multiple independent pulses. The potential this new scheme demonstrated evolution...
To investigate the threshold and accuracy of intraoral scanning in measuring freeform human enamel surfaces.Software softgauges, ranging between 20 160 µm depth, were used to compare four workflow analysis techniques measure step height on a surface; with or without reference areas combination surface-subtraction establish which produced most accurate outcome. Having established optimum combination, 1.5 mm diameter, individual depths from 11 81 created separately 14 unpolished samples then...
The feasibility of a transmission x-ray microscope operating in the 3-7 keV photon energy range using phase zone plates (ZPs) has been tested. It demonstrated that, at 4 keV, structures smaller than 150 nm can be resolved with good contrast exposure times second to minute range. A large diameter gold ZP was used as condenser and tungsten an outermost width 128 high spatial resolution imaging objective lens. Images field size 10×10 μm2 were acquired charge coupled device camera optically...
This in-vitro study investigated limitations of intra-oral scanners (IOS) in capturing palatal defects at decreased mouth openings. The trueness and precision composite 3D-printed models from Cone-Beam Computed Tomography (CBCT) IOS were measured.
The aim for this pilot study was to investigate the effect of a sodium fluoride varnish on step height measured by profilometer from human enamel worn healthy volunteers with novel in situ/ex vivo erosion design.
SUMMARY A brief description is given of the eight image signals that can be simultaneously recorded in digital form using an appropriate data recording system and high resolution STEM; this involves a set detectors covering bright dark field. Details are provided collection manipulation for STEM, including on‐line estimation off‐focus distance, assessment astigmatism, signal to noise ratio any or all detectors; examples three procedures given. The use discussed together with some aspects...
A VG HB5 STEM has been modified to allow computer controlled contamination writing on thin Carbon substrates. Line widths of 20 nM and height width aspect ratios better than 5:1 can be drawn. This used fabricate Fresnel zone plates. patching process is involved with registration an accuracy 2.5 nM. Methods techniques have developed compensate for non-linearity the field scans together specimen drift. Zone plates 50 NM diameter outer 40 con-structed.
A scanning transmission x-ray microscope has been used to form images with 380-eV x rays on the undulator beamline at Daresbury synchrotron radiation source. resolution of 80 nm achieved using Fresnel zone-plate focusing optics and reasonable signal-to-noise ratios can be acquired in less than 30 min.
The time-integrated spatial coherence of neonlike germanium x-ray laser radiation has been studied with a new dispersing diagnostic. Angle-dependent data are recorded by sampling the diverging beam at each lasing wavelength in several directions simultaneously. Measurements coherence, and hence effective source sizes, relevant to output beams from double-slab targets for J=2–1 spectral lines wavelengths 28.6, 23.6, 23.2 nm J=0–1 line 19.6 show differences, which indicate different conditions...
An imaging microscope, comprising a Schwarzchild condenser and zone-plate optical arrangement, has been established on the Vulcan Nd:glass laser system at Rutherford Appleton Laboratory. Magnified images of simple test structures have taken in x-ray transmission single subnanosecond shot by using doublet radiation 23.2 23.6 nm from collisionally pumped Ne-like germanium. Image resolutions ~0.15 μm measured. The results are proof principle demonstrate that potentially suboptical resolution...
A scanning transmission x-ray microscope with Fresnel zone-plate focusing optics has been used to form images monochromatic 400 eV x-rays. In initial experiments on the undulator beamline at SERC Daresbury Laboratory's synchrotron radiation source, a resolution of about 150 nm achieved focused flux more than 104 photons per second.
The spatial coherence of a nanosecond pulsed germanium collisionally excited x-ray laser is measured experimentally for three target configurations. diagnostic based on Young's slit interference fringes with dispersing element to resolve the 23.2- and 23.6-nm spectral lines. Target configurations include double-slab target, known as injector, geometries in which injector image relayed seed either an additional single-slab or second target. A special feature this study observation change...
We have been involved in all aspects of nanofabrication for many years. This includes zone plates, calibration test objects, gratings, Young's slits, and nanohole arrays, both ordered random. Most our nanostructures are fabricated tungsten, a material very well suited wide range x‐ray energies, with the added advantage that it is closest thermally matched to usual Si3N4 substrate. Alternative materials used when there clear advantage; example, we can fabricate optics EUV operation molybdenum...
Abstract A scanning x‐ray microscope has been built at the Daresbury synchrotron radiation source and used to obtain images soft wavelengths (∼2–4 nm). The focusing element of is a zone plate, fabricated by contamination writing process developed King's College. Zone plates with finest widths, hence theoretical resolutions, below 20 nm have in this way. material carbon, as such unsuitable for high‐efficiency focusing. In order increase plate efficiency, shadowing pattern transfer replicate...
Tungsten is a material well suited for the fabrication of diffractive optics intended use at high (multi KeV) X-ray energies. It however particularly difficult to deposit, especially when relatively thick (>500 nm) films on thin membranes are needed. In such case, deposition stress and granularity lead membrane deformation or destruction. We have devoted lot time effort in identifying controlling critical parameters, we now position successfully deposit up 1 μm films, which can be processed...