Edward E. Domning

Bio: Edward E. Domning is an academic researcher from Lawrence Berkeley National Laboratory. The author has contributed to research in topics: Beamline & Metrology. The author has an hindex of 14, co-authored 32 publications receiving 964 citations.

A dedicated superbend x-ray microdiffraction beamline for materials, geo-, and environmental sciences at the advanced light source.

Abstract: A new facility for microdiffraction strain measurements and microfluorescence mapping has been built on beamline 12.3.2 at the advanced light source of the Lawrence Berkeley National Laboratory. This beamline benefits from the hard x-radiation generated by a 6 T superconducting bending magnet (superbend). This provides a hard x-ray spectrum from 5 to 22 keV and a flux within a 1 microm spot of approximately 5x10(9) photons/s (0.1% bandwidth at 8 keV). The radiation is relayed from the superbend source to a focus in the experimental hutch by a toroidal mirror. The focus spot is tailored by two pairs of adjustable slits, which serve as secondary source point. Inside the lead hutch, a pair of Kirkpatrick-Baez (KB) mirrors placed in a vacuum tank refocuses the secondary slit source onto the sample position. A new KB-bending mechanism with active temperature stabilization allows for more reproducible and stable mirror bending and thus mirror focusing. Focus spots around 1 microm are routinely achieved and allow a variety of experiments, which have in common the need of spatial resolution. The effective spatial resolution (approximately 0.2 microm) is limited by a convolution of beam size, scan-stage resolution, and stage stability. A four-bounce monochromator consisting of two channel-cut Si(111) crystals placed between the secondary source and KB-mirrors allows for easy changes between white-beam and monochromatic experiments while maintaining a fixed beam position. High resolution stage scans are performed while recording a fluorescence emission signal or an x-ray diffraction signal coming from either a monochromatic or a white focused beam. The former allows for elemental mapping, whereas the latter is used to produce two-dimensional maps of crystal-phases, -orientation, -texture, and -strain/stress. Typically achieved strain resolution is in the order of 5x10(-5) strain units. Accurate sample positioning in the x-ray focus spot is achieved with a commercial laser-triangulation unit. A Si-drift detector serves as a high-energy-resolution (approximately 150 eV full width at half maximum) fluorescence detector. Fluorescence scans can be collected in continuous scan mode with up to 300 pixels/s scan speed. A charge coupled device area detector is utilized as diffraction detector. Diffraction can be performed in reflecting or transmitting geometry. Diffraction data are processed using XMAS, an in-house written software package for Laue and monochromatic microdiffraction analysis.

A beamline for high-pressure studies at the advanced light source with a superconducting bending magnet as the source

Abstract: A new facility for high-pressure diffraction and spectroscopy using diamond anvil high-pressure cells has been built at the Advanced Light Source on Beamline 12.2.2. This beamline benefits from the hard X-radiation generated by a 6 Tesla superconducting bending magnet (superbend). Useful x-ray flux is available between 5 keV and 35 keV. The radiation is transferred from the superbend to the experimental enclosure by the brightness preserving optics of the beamline. These optics are comprised of: a plane parabola collimating mirror (M1), followed by a Kohzu monochromator vessel with a Si(111) crystals (E/{Delta}E {approx} 7000) and a W/B{sub 4}C multilayer (E/{Delta}E {approx} 100), and then a toroidal focusing mirror (M2) with variable focusing distance. The experimental enclosure contains an automated beam positioning system, a set of slits, ion chambers, the sample positioning goniometry and area detectors (CCD or image-plate detector). Future developments aim at the installation of a second end station dedicated for in situ laser-heating on one hand and a dedicated high-pressure single-crystal station, applying both monochromatic as well as polychromatic techniques.

Sub-microradian surface slope metrology with the ALS Developmental Long Trace Profiler

Abstract: A new low-budget slope measuring instrument, the Developmental Long Trace Profiler (DLTP), was recently brought to operation at the ALS Optical Metrology Laboratory. The design, instrumental control and data acquisition system, initial alignment and calibration procedures, as well as the developed experimental precautions and procedures are also described in detail. The capability of the DLTP to achieve sub-microradian surface slope metrology is verified via cross-comparison measurements with other high-performance slope measuring instruments when measuring the same high-quality test optics. The directions of future work to develop a surface slope measuring profiler with nano-radian performance are also discussed.

Suite of three protein crystallography beamlines with single superconducting bend magnet as the source

Abstract: At the Advanced Light Source (ALS), three protein crystallography (PX) beamlines have been built that use as a source one of the three 6 Tesla single pole superconducting bending magnets (superbends) that were recently installed in the ring. The use of such single pole superconducting bend magnets enables the development of a hard x-ray program on a relatively low energy 1.9 GeV ring without taking up insertion device straight sections. The source is of relatively low power, but due to the small electron beam emittance, it has high brightness. X-ray optics are required to preserve the brightness and to match the illumination requirements for protein crystallography. This was achieved by means of a collimating premirror bent to a plane parabola, a double crystal monochromator followed by a toroidal mirror that focuses in the horizontal direction with a 2:1 demagnification. This optical arrangement partially balances aberrations from the collimating and toroidal mirrors such that a tight focused spot size is achieved. The optical properties of the beamline are an excellent match to those required by the small protein crystals that are typically measured. The design and performance of these new beamlines are described.

Modular soft x-ray spectrometer for applications in energy sciences and quantum materials.

Abstract: Over the past decade, the advances in grating-based soft X-ray spectrometers have revolutionized the soft X-ray spectroscopies in materials research. However, these novel spectrometers are mostly dedicated designs, which cannot be easily adopted for applications with diverging demands. Here we present a versatile spectrometer design concept based on the Hettrick-Underwood optical scheme that uses modular mechanical components. The spectrometer's optics chamber can be used with gratings operated in either inside or outside orders, and the detector assembly can be reconfigured accordingly. The spectrometer can be designed to have high spectral resolution, exceeding 10 000 resolving power when using small source (∼1μm) and detector pixels (∼5μm) with high line density gratings (∼3000 lines/mm), or high throughput at moderate resolution. We report two such spectrometers with slightly different design goals and optical parameters in this paper. We show that the spectrometer with high throughput and large energy window is particularly useful for studying the sustainable energy materials. We demonstrate that the extensive resonant inelastic X-ray scattering (RIXS) map of battery cathode material LiNi1/3Co1/3Mn1/3O2 can be produced in few hours using such a spectrometer. Unlike analyzing only a handful of RIXS spectra taken at selected excitation photon energies across the elemental absorption edges to determine various spectral features like the localized dd excitations and non-resonant fluorescence emissions, these features can be easily identified in the RIXS maps. Studying such RIXS maps could reveal novel transition metal redox in battery compounds that are sometimes hard to be unambiguously identified in X-ray absorption and emission spectra. We propose that this modular spectrometer design can serve as the platform for further customization to meet specific scientific demands.

Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry

Abstract: A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.

Coupling between oxygen redox and cation migration explains unusual electrochemistry in lithium-rich layered oxides

Abstract: Lithium-rich layered transition metal oxide positive electrodes offer access to anion redox at high potentials, thereby promising high energy densities for lithium-ion batteries. However, anion redox is also associated with several unfavorable electrochemical properties, such as open-circuit voltage hysteresis. Here we reveal that in Li1.17-x Ni0.21Co0.08Mn0.54O2, these properties arise from a strong coupling between anion redox and cation migration. We combine various X-ray spectroscopic, microscopic, and structural probes to show that partially reversible transition metal migration decreases the potential of the bulk oxygen redox couple by > 1 V, leading to a reordering in the anionic and cationic redox potentials during cycling. First principles calculations show that this is due to the drastic change in the local oxygen coordination environments associated with the transition metal migration. We propose that this mechanism is involved in stabilizing the oxygen redox couple, which we observe spectroscopically to persist for 500 charge/discharge cycles.

Synchrotron X-ray Analytical Techniques for Studying Materials Electrochemistry in Rechargeable Batteries

Abstract: Rechargeable battery technologies have ignited major breakthroughs in contemporary society, including but not limited to revolutions in transportation, electronics, and grid energy storage The remarkable development of rechargeable batteries is largely attributed to in-depth efforts to improve battery electrode and electrolyte materials There are, however, still intimidating challenges of lower cost, longer cycle and calendar life, higher energy density, and better safety for large scale energy storage and vehicular applications Further progress with rechargeable batteries may require new chemistries (lithium ion batteries and beyond) and better understanding of materials electrochemistry in the various battery technologies In the past decade, advancement of battery materials has been complemented by new analytical techniques that are capable of probing battery chemistries at various length and time scales Synchrotron X-ray techniques stand out as one of the most effective methods that allow for near