J. L. White
A5055904289- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Hydrogen Storage and Materials
- Laser-Matter Interactions and Applications
- Spectroscopy and Quantum Chemical Studies
- Plant Virus Research Studies
- High-Energy Particle Collisions Research
- Particle Accelerators and Free-Electron Lasers
- Advanced Chemical Physics Studies
- Superconductivity in MgB2 and Alloys
- Nuclear physics research studies
- Boron and Carbon Nanomaterials Research
- CO2 Reduction Techniques and Catalysts
- Electron and X-Ray Spectroscopy Techniques
- Ammonia Synthesis and Nitrogen Reduction
- Mass Spectrometry Techniques and Applications
- Advanced NMR Techniques and Applications
- Particle Detector Development and Performance
- Particle accelerators and beam dynamics
- Hybrid Renewable Energy Systems
- X-ray Spectroscopy and Fluorescence Analysis
- Atomic and Subatomic Physics Research
- Plant Disease Resistance and Genetics
- Fuel Cells and Related Materials
- Crystallography and Radiation Phenomena
Sandia National Laboratories California
2016-2020
University of Alaska Fairbanks
2020
Lawrence Livermore National Security
2016-2018
Sandia National Laboratories
2017-2018
Princeton University
2012-2016
Stanford University
1996-2014
SLAC National Accelerator Laboratory
1995-2014
Mitchell Institute
2013
Texas A&M University
2013
Pulse Biosciences (United States)
2011
The spin structure function of the neutron gn1 has been determined over range 0.03<x<0.6 at an average Q2 2 (GeV/c)2 by measuring asymmetry in deep inelastic scattering polarized electrons from a 3He target energies between 19 and 26 GeV. integral is found to be F10gn1(x)dx=-0.022±0.011. Earlier reported proton results together with Bjorken sum rule predict F10gn1(x)dx=-0.059±0.019.Received 1 April 1993DOI:https://doi.org/10.1103/PhysRevLett.71.959©1993 American Physical Society
The reduction of CO2 on tin cathodes was studied using in situ attenuated total reflectance infrared spectroscopy (ATR-IR). Thin films a mixed Sn/SnOx species were deposited onto single-crystal ZnSe ATR crystal. Peaks centered at about 1500, 1385, and 1100 cm–1, attributed to surface-bound monodentate carbonate species, consistently present under conditions which takes place. It shown that these peaks are only potentials where is observed. Moreover, disappear if the pH reaction too low or...
Measurements are reported of the proton and deuteron spin structure functions ${g}_{1}^{p}$ ${g}_{1}^{d}$ at beam energies 29.1, 16.2, 9.7 GeV, ${g}_{2}^{p}$ ${g}_{2}^{d}$ a energy 29.1 GeV. The integrals ${\ensuremath{\Gamma}}_{p}={\ensuremath{\int}}_{0}^{1}{g}_{1}^{p}{(x,Q}^{2})dx$ ${\ensuremath{\Gamma}}_{d}={\ensuremath{\int}}_{0}^{1}{g}_{1}^{d}{(x,Q}^{2})dx$ were evaluated fixed ${Q}^{2}=3(\mathrm{GeV}{/c)}^{2}$ using full data set to yield...
The interactions of CO2 with indium metal electrodes have been characterized for electrochemical formate production. electrode oxidation state, morphology, and voltammetric behaviors were systematically probed. It was found that an anodized stabilized production over time compared to etched bearing a native oxide in applied potential range -1.4 -1.8 V vs SCE. In addition, it observed is the major product at unprecedentedly low overpotentials surface. A surface hydroxide species suggesting...
We have measured the ratio $\frac{{g}_{1}^{p}}{{F}_{1}^{p}}$ over range $0.029<x<0.8$ and $1.3<{Q}^{2}<10$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$ using deep-inelastic scattering of polarized electrons from ammonia. An evaluation integral $\ensuremath{\int}{0}^{1}{g}_{1}^{p}(x, {Q}^{2})\mathrm{dx}$ at fixed ${Q}^{2}=3$ yields 0.127\ifmmode\pm\else\textpm\fi{}0.004(stat)\ifmmode\pm\else\textpm\fi{}0.010(syst), in agreement with previous experiments, but well below Ellis-Jaffe sum...
The neutron longitudinal and transverse asymmetries A1n A2n have been extracted from deep inelastic scattering of polarized electrons by a He3 target at incident energies 19.42, 22.66, 25.51 GeV. measurement allows for the determination spin structure functions g1n(x, Q2) g2n(x, over range 0.03<x<0.6 an average Q2 2 (GeV/c)2. data are used evaluation Ellis-Jaffe Bjorken sum rules. function is small negative within our measurement, yielding integral ∫0.030.6g1n(x)dx=−0.028±0.006 (stat)±0.006...
We report on a high-statistics measurement of the deuteron spin structure function ${g}_{1}^{d}$ at beam energy 29 GeV in kinematic range $0.029<x<0.8$ and $1<{Q}^{2}<10$ (GeV $/c$${)}^{2}$. The integral ${\ensuremath{\gamma}}_{1}^{d}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\ensuremath{\int}{1}^{}{g}_{1}^{d}\mathrm{dx}$ evaluated fixed ${Q}^{2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}3$ $/c$${)}^{2}$ gives...
The first time-resolved x-ray/optical pump-probe experiments at the SLAC Linac Coherent Light Source (LCLS) used a combination of feedback methods and post-analysis binning techniques to synchronize an ultrafast optical laser linac-based x-ray laser. Transient molecular nitrogen alignment revival features were resolved in time-dependent x-ray-induced fragmentation spectra. These find temporal overlap pump probe pulses. strong-field dissociation generated quasi-bound dications was establish...
The Linac Coherent Light Source free electron laser is a source of high brightness x rays, 2×1011 photons in ∼5 fs pulse, that can be focused to produce double core vacancies through rapid sequential ionization. This enables vacancy Auger spectroscopy, an entirely new way study femtosecond chemical dynamics with electrons probe the local valence structure molecules near specific atomic core. Using 1.1 keV for x-ray ionization impulsively aligned molecular nitrogen, we observed rich...
Nanoparticles of indium, indium hydroxide, and oxide were synthesized evaluated for their electrocatalytic abilities in the reduction CO2 to formate. These nanoparticles characterized with several microscopic spectroscopic techniques order investigate structure surface features. Their electrochemical behavior was also probed through voltammetry bulk electrolysis. faradaic efficiencies approaching 100% achieved on these particles at potentials as positive −1.3 V vs. Ag/AgCl, which represents...
We have constructed an automated learning apparatus to control quantum systems. By directing intense shaped ultrafast laser pulses into a variety of samples and using measurement the system as feedback signal, we are able reshape direct desired state. The signal is input adaptive algorithm. This algorithm programs computer-controlled, acousto-optic modulator pulse shaper. generates new based on success previous in achieving predetermined goal.
We have measured proton and deuteron virtual photon-nucleon asymmetries ${A}_{2}^{p}$ ${A}_{2}^{d}$ structure functions ${g}_{2}^{p}$ ${g}_{2}^{d}$ over the range $0.03<x<0.8$ $1.3<{Q}^{2}<10(\mathrm{GeV}/c{)}^{2}$ by inelastically scattering polarized electrons off ammonia targets. Results for ${A}_{2}$ are significantly smaller than positivity limit $\sqrt{R}$ both Within experimental precision ${g}_{2}$ data well described twist-2 contribution, ${g}_{2}^{\mathrm{WW}}$. Twist-3 matrix...
We demonstrate a new method for coherent control of bond excitation in the strong field regime. can selectively excite one or more Raman-active modes molecular liquid without need externally generated sources separated by Stokes frequency. The employs with an intense phase-shaped pulse learning loop.
The cross section for quasielastic $^{12}\mathrm{C}$(e,e'p) scattering has been measured at momentum transfer ${\mathit{Q}}^{2}$=1, 3, 5, and 6.8 (GeV/c${)}^{2}$. results are consistent with from a single nucleon as the dominant process. nuclear transparency is obtained compared theoretical calculations that incorporate color effects. No significant rise of ${\mathit{Q}}^{2}$ observed.
The analyzing power AN in inclusive π− and π+ production has been measured with a 200 GeV/c transversely polarized antiproton beam over wide xF range (0.2≤xF≤0.9) at moderate pT (0.2≤pT≤1.5GeV/c). asymmetry increases increasing from zero to large positive values for π−'s, decreases negative π+'s. A threshold the onset of is observed about pT∼0.5GeV/c, below which essentially above (decreases) π−'s ( π+'s) covered range.Received 17 April...
The architecture of an active resistive mesh containing both positive and negative resistors to implement a Gaussian convolution in two dimensions is described. With embedded array photoreceptors, this may be used for image detection smoothing. width continuously variable by 2:1 under user control. Analog circuits 45*40 on 2- mu m CMOS integrated circuit, perform entire 20 s applied images.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
We have studied the photoinduced isomerization from 1,3-cyclohexadiene to 1,3,5-hexatriene in presence of an intense ultrafast laser pulse. find that field maximally suppresses if it is both polarized parallel excitation dipole and present 50 fs after initial photoabsorption, at time when system expected be vicinity a conical intersection mediates this structural transition. A modified ab initio multiple spawning (AIMS) method shows induces resonant coupling between excited state ground...