A5043159124- Optical Coatings and Gratings
- Electromagnetic Scattering and Analysis
- Atomic and Molecular Physics
- Electromagnetic Simulation and Numerical Methods
- Plasma Diagnostics and Applications
- Calibration and Measurement Techniques
- Laser Design and Applications
- Mass Spectrometry Techniques and Applications
- Nuclear Physics and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Laser-Matter Interactions and Applications
- Electron and X-Ray Spectroscopy Techniques
- Laser-induced spectroscopy and plasma
- Advancements in Photolithography Techniques
- Advanced Antenna and Metasurface Technologies
- Thin-Film Transistor Technologies
- Solar and Space Plasma Dynamics
- Nuclear Materials and Properties
- Electromagnetic Compatibility and Measurements
- Photocathodes and Microchannel Plates
- Silicon and Solar Cell Technologies
- Geological Modeling and Analysis
- Nanoparticles: synthesis and applications
- Advanced X-ray Imaging Techniques
- Planetary Science and Exploration
Nevada National Security Site
2023-2025
Vehicle Technologies Office
2025
Sandia National Laboratories
2024
Sandia National Laboratories California
2023
The University of Texas at El Paso
2018-2022
Rice University
2019-2022
Brigham Young University
2006-2021
Systems Engineering Research Center
2020
Provo College
2009
HRL Laboratories (United States)
1986-2002
The application of nanomaterials as a method to overcome plant stress and increase crop yield is relatively new compared the use fertilizers pesticides in agricultural production. In present study, manganese (III) oxide nanoparticles (MnNPs) were investigated nanopriming agent alleviate salinity Capsicum annuum L. during germination at 100 mM NaCl. general, root growth both nonsalt salt-stressed seedlings was significantly improved by MnNPs (0.1, 0.5, 1 mg/L). Scanning electron microscopy...
Abstract Sample return capsules (SRCs) entering Earth’s atmosphere at hypervelocity from interplanetary space are a valuable resource for studying meteor phenomena. The 2023 September 24 arrival of the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer SRC provided an unprecedented chance geophysical observations well-characterized source with known parameters, including timing trajectory. A collaborative effort involving researchers 16 institutions...
The accumulation of engineered nanomaterials (ENMs) will increase as more applications are discovered for their unique properties and characteristics. Additionally, the presence in environment becomes exacerbated consumer products containing nanoparticles approved use. Some examples nano-enabled include cosmetics, plastic packaging, clothing, textiles, paints. Once exposed to natural environmental settings, a variety transformations may occur leading agglomeration, dissolution, or secondary...
Nanotechnology-enabled water treatment technologies have the potential to outperform conventional systems, but we must understand how produce, use, and dispose of these in a safe sustainable way.
We use laser high-order harmonics and a polarization-ratio-reflectance technique to determine the optical constants of copper oxidized in wavelength range 10-35 nm. This measurement resolves previously conflicting data sets, where disagreement on extreme ultraviolet most likely arises from inadvertent oxidation samples before measurement.
We demonstrate that a method of moments scattering code employing high-order methods can compute accurate values for the cross section smooth body more efficiently than standard low-order methods. Use also makes it practical to provide meaningful accuracy estimates computed solutions.
We have used laser-induced fluorescence (LIF) to monitor the charge-exchange ion erosion of molybdenum accelerator electrode in thrusters. This real-time, nonintrusive method was implemented by operating a 30cm-diam ring-cusp thruster using xenon propellant. With at total power 5 kW, laser radiation wavelength 390 nm (corresponding ground state atomic transition molybdenum) directed through extracted beam adjacent downstream surface electrode. Molybdenum atoms, sputtered from this as result...
The results of investigation a capillary discharge plasma, used as source intense VUV radiation and soft X-rays, are presented. plasma was generated during the low-inductance condensers in gas-filled ceramic capillary. Intense line observed broad spectral range (30-400 Å) various gases (CO2, Ne, Ar, Kr, Xe). absolute yield for xenon ~5 mJ (2π sr)-1 pulse-1 within band width 9 Å at 135 Å. Such can be practical applications, such EUV projection lithography, microscopy biological objects 'water...
We use a laser high-harmonics-based extreme-ultraviolet (EUV) polarimeter to determine the optical constants of elemental uranium in wavelength range from 10 47 nm. The are extracted measured ratio p-polarized s-polarized reflectance thin film deposited situ. thickness is inferred spectroscopic ellipsometry measurement sample after complete oxidation room air. Uranium has been used as high-reflectance material EUV. However, difficulties with prevented its careful characterization previous...
We present the measured reflectances (Beamline 6.3.2, ALS at LBNL) of naturally oxidized uranium and nickel thin films from 2.7 to 11.6 nm 5°, 10°, 15° grazing incidence. These show that uranium, as UO<sub>2</sub>, can fulfill its promise highest known single surface reflector for this portion soft x-ray region, being nearly twice reflective in 5-10 region. This is due large index refraction coupled with low absorption. Nickel commonly used applications astronomy synchrotrons....
To maintain high, broad-band reflectance, thin transparent fluoride layers, such as MgF 2 , are used to protect aluminum mirrors against oxidation. In this study, we present, for the first time, combined X-ray photoelectron spectroscopy (XPS) and spectroscopic ellipsometric (SE) studies of oxidation a function overlayer thickness (thickness 0-5 nm). Dynamic SE tracks extent oxide growth every ca. 2s over period several hours after evaporated Al + bilayer is removed from deposition chamber....
Measurements of the differential cross sections for $^{4}(\ensuremath{\gamma}$,n${)}^{3}$He and $^{4}(\ensuremath{\gamma}$,p${)}^{3}$H reactions have been performed photon energies in 100--360 MeV region. Results were obtained nucleon center-of-mass angles close to 60\ifmmode^\circ\else\textdegree\fi{}, 90\ifmmode^\circ\else\textdegree\fi{}, 120\ifmmode^\circ\else\textdegree\fi{} by detecting recoiling nuclei with a magnetic spectrometer. Both (\ensuremath{\gamma},p) (\ensuremath{\gamma},n)...
The fast multipole method (FMM) dramatically reduces the time and memory required to compute radar cross sections antenna radiation patterns compared dense matrix techniques. We have implemented FMM in a of moments (MoM) program electromagnetic scattering from large bodies arbitrary shape. compare using that for direct iterative solutions impedance matrix.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
The reported optical constants of uranium differ from that vacuum significantly more than other elements do over the range about 150 to 350 eV. This suggests could be used produce high reflectance imaging mirrors for many soft x-ray applications. Elemental is too chemically active as a front surface mirror without protection. We computed expected carbon-coated films and uranium-nickel alloys low-angle reflectors. Carbon mostly transparent below its K absorption edge at 283 10 degrees grazing...
We have developed a new family of EUV multilayer mirror coatings using uranium. Using this approach we coated set six mirrors for the Imager, component IMAGE mission. This mission is Medium Explorer (MIDEX) program, which scheduled launch early in 2000. The Imager will study distribution He<SUP>+</SUP> Earth's plasmasphere by detecting its resonantly scattered emission at 30.4 nm (41 eV) and produce images structure dynamics cold plasma on global scale. There is, however, bright 58.4 (21...
Inclusive photoproton cross sections for the reaction $\mathrm{Cu}(\ensuremath{\gamma},p)X$ have been measured a photon energy of 300 MeV at proton angles 45\ifmmode^\circ\else\textdegree\fi{}, 90\ifmmode^\circ\else\textdegree\fi{}, and 135\ifmmode^\circ\else\textdegree\fi{}, 150 45\ifmmode^\circ\else\textdegree\fi{}. The data are compared with an intranuclear-cascade calculation Ni(${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$,$p$) data. angular distribution is analyzed to obtain...