In Situ Structural Observation of a Substrate- and Peroxide-Bound High-Spin Ferric-Hydroperoxo Intermediate in the P450 Enzyme CYP12
The data will soon be made available.
LCLS↗
SEARCH · Engineering Papers
Results for “LCLS”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Ionization by XFEL radiation produces distinct structure in liquid water
Please check the README file for more information about the dataset.
CXI↗
Enzyme intermediates captured “on the fly” by mix-and-inject serial crystallography
Not Available
59 BASIC BIOLOGICAL SCIENCES↗
Materials laboratories of the future for alloys, amorphous, and composite materials
In alignment with the Materials Genome Initiative and as the product of a workshop sponsored by the US National Science Foundation, we define a vision for materials laboratories of the future in alloys, amorphous materials, and composite materials; chart a roadmap for realizing this vision; identify technical bottlenecks and barriers to access; and propose pathways to equitable and democratic access to integrated toolsets in a manner that addresses urgent societal needs, accelerates technological innovation, and enhances manufacturing competitiveness. Spanning three important materials classes, this article summarizes the areas of alignment and unifying themes, distinctive needs of different materials research communities, key science drivers that cannot be accomplished within the capabilities of current materials laboratories, and open questions that need further community input. Here, we provide a broader context for the workshop, synopsize the salient findings, outline a shared vision for democratizing access and accelerating materials discovery, highlight some case studies across the three different materials classes, and identify significant issues that need further discussion.
36 MATERIALS SCIENCE↗
Analysis strategy for ultrafast X-ray photon correlation spectroscopy
We explain an analysis strategy for ultrafast X-ray photon correlation spectroscopy, a technique enabled by X-ray free electron lasers to probe nano- and atomic-scale dynamics in complex systems on nanosecond timescales or faster. Central to the technique is the methodology for extracting contrast in coherent X-ray diffraction patterns, known as speckle patterns. Guided by simulations, we analyze common challenges and examine errors encountered in contrast extraction. A method for accurately determining contrast amid shot noise across a wide range of count rates is presented.
36 MATERIALS SCIENCE↗
Brochure on the 2024 ASCR Workshop on Energy-Efficient Computing for Science
Large-scale computing has enabled numerous scientific discoveries, including ground-breaking achievements facilitated by the US Department of Energy (DOE) supercomputers and advances in applied mathematics and computer science. While important advances were made in energy efficiency to enable exascale computing, continued efforts are needed to dramatically improve the energy efficiency of the next generation of high-performance computing (HPC) systems and, more broadly, AI data centers. Without substantial improvements in energy efficiency, the energy consumption associated with computing could become a limiting factor for future scientific discovery, national security, and technological advancement.
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
Report for the 2024 ASCR Workshop on Energy-Efficient Computing for Science
In September 2024, the US Department of Energy’s Advanced Scientific Computing Research pro gram convened a Workshop on Energy-Efficient Computing for Science to address the critical research challenges and opportunities in this field. The workshop brought together experts from academia, government, and industry to explore innovative approaches to improve energy efficiency across the computing stack over the next two decades. Participants identified five priority research directions (PRDs) that emphasize the need for a holistic approach.
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
X-ray Spectroscopic Studies of a Solid-Density Germanium Plasma Created by a Free Electron Laser
The generation of solid-density plasmas in a controlled manner using an X-ray free electron laser (XFEL) has opened up the possibility of diagnosing the atomic properties of hot, strongly coupled systems in novel ways. Previous work has concentrated on K-shell emission spectroscopy of low Z (<= 14) elements. Here, we extend these studies to the mid-Z(=32) element Germanium, where the XFEL creates copious L-shell holes, and the plasma conditions are interrogated by recording of the associated L-shell X-ray emission spectra. Given the desirability of generating as uniform a plasma as possible, we present here a study of the effects of the FEL photon energy on the temperatures and electron densities created, and their uniformity in the FEL beam propagation direction. We show that good uniformity can be achieved by tuning the photon energy of the XFEL such that it does not overlap significantly with L-shell to M-shell bound-bound transitions, and lies below the L-edges of the ions formed during the heating process. Reasonable agreement between experiment and simulations is found for the emitted X-ray spectra, demonstrating that for these higher Z elements, the selection of appropriate XFEL parameters is important for achieving uniformity in the plasma conditions.
70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
An Energy Tunable X-Ray Delay Device
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43 PARTICLE ACCELERATORS↗
Experiment Provides the Best Look Yet at 'Warm Dense Matter' at Cores of Giant Planets
In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as it transitions into a superhot, highly compressed concoction known as “warm dense matter.”
36 MATERIALS SCIENCE↗
Scientists Get First Glimpse of a Chemical Bond Being Born
Scientists have used an X-ray laser at the Department of Energy’s SLAC National Accelerator Laboratory to get the first glimpse of the transition state where two atoms begin to form a weak bond on the way to becoming a molecule.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Ultrafast Electron Diffraction: How It Works
A new technology at SLAC uses high-energy electrons to unravel motions in materials that are faster than a tenth of a trillionth of a second, opening up new research opportunities in ultrafast science.
43 PARTICLE ACCELERATORS↗
Interview with Ryan Coffee – What is a Femtosecond?
Ryan Coffee, scientist at SLAC's Linac Coherent Light Source X-ray laser, explains, “What is a femtosecond?”
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Minimization of thermal deformation in crystal optics for high repetition-rate FEL
Minimizing thermal deformation in X-ray crystal optics is crucial for preserving coherence and wavefront in high-repetition-rate free-electron lasers (FELs). This study presents two approaches to reduce pulse-by-pulse transient thermal deformation in diamond crystals used in cavity-based X-ray FELs (CBXFELs): (1) cryogenic cooling with liquid nitrogen (LN₂), and (2) second-order correction via focusing optics. We revisit the temperature-dependent thermal-mechanical properties of diamond and silicon, implement a finite-element analysis (FEA) method to accelerate convergence to a quasisteady-state regime. Results show that LN₂-cooled diamond crystals meet the stringent deformation requirement of less than 15 pm RMS for the pulse at mJ scale at 1 MHz repetition frequency, and up to 1.5 mJ for 100 kHz. Second-order correction by using focusing elements within the cavity can reduce the impact of thermal deformation for both liquid nitrogen and water cooling.
free electron laser↗