This project was concerned with high-accuracy measurements of electron-impact photoemission cross sections for transitions of atoms and molecules in the EUV spectral region (30 nm to 200 nm). The spectrometer-detector system that was employed in the measurements was calibrated using well-parameterized synchrotron radiation. The 58.4 resonance line of He ...
Energy Citations Database
DOE Information Bridge
We calculate the photoemission spectral function of the one-dimensional Hubbard model away from half filling using the dynamical density-matrix renormalization group method. An approach for calculating momentum-dependent quantities in finite open chains is presented. Comparison with exact Bethe ansatz results demonstrates the unprecedented accuracy of our ...
PubMed
NASA Astrophysics Data System (ADS)
A method of band mapping providing full control of the three-dimensional k is described in detail. Angle-dependent very-low-energy electron diffraction is applied to determine the photoemission final states along a Brillouin zone symmetry line parallel to the surface; photoemission out of these states is then utilized to map the valence bands in the ...
An optical screen for electronic image intensifier tubes is designed in which the separation between the zinc sulfide phosphor particles and the photoelectric particles is made small for increased accuracy in the reproduction of the x-ray image. The screen has a network of sockets or holes which are filled with phosphor, and the photoemissive ...
Absolute photoemission cross section data have been measured for the dissociative excitation of H2S by electrons in the impact energy range from threshold to 300 eV. Emissions in the vacuum ultraviolet spectral region have been observed and quantified using emission from H2 as a secondary standard. Numerous dissociation pathways have been identified. H2S data are important in ...
The multiconfiguration time-dependent Hartree-Fock and the time-dependent configuration interaction singles method are applied to the correlated many-electron dynamics of a one-dimensional jellium model system. We study the scattering of an initially free electron at a model film in the framework of both approaches. In particular, both methods are compared with regard to how they describe the ...
Initial results of an experiment to measure the photoemission of single dust grains as a function of
NASA Technical Reports Server (NTRS)
... Title : PHOTOEMISSION ELECTRON MICROSCOPY OF GROWTH OF GRAIN BOUNDARY FERRITE ALLOTRIOMORPHS IN CHROMIUM STEEL,. ...
DTIC Science & Technology
Results of investigations are reviewed to assess the polarization dependence of photoemission in the
The copper K? photoemission spectra is one of the most widely studied. Recent Dirac-Fock calculations have produced transition energies in good agreement with experiment, though they have relied on approximations that may not be transferable to other complex atoms in which uncertainties in theoretical results are dominated by poor convergence. Through a detailed examination of ...
A high resolution chemical ionization mass spectrometry system of high sensitivity has been developed. The resolving power of the instrument M/Delta M exceeds 50,000, and the sensitivity and quantitative accuracy are comparable to electron impact mass spe...
National Technical Information Service (NTIS)
Some general relations are obtained comparing the cross sections for dissociative recombination of molecular ions, accompanied by the formation of highly excited atoms, with the cross sections for dissociation by electron impact. Calculations are performed for the H2(+) ion. The accuracy of the dipole approximation for evaluating the ...
A device for detecting optical energy signals in an optical path is provided by combining a layer of photoemissive material overlying the optical path and a grounded first electrode positioned in electrical contact with the layer of photoemissive material...
The band dispersion and lifetime width for the sp valence electrons in Ag are determined with unprecedented accuracy as a function of temperature. The resulting Fermi wave vector challenges the venerable de Haas{endash}van Alphen value, and shows the latter to be off by 1{percent}. The electron-phonon mass enhancement parameter is deduced for the first time for a bulk state, ...
A discussion is presented on photoemission and photomultipliers. A short description of the physics of photoemission is followed by a discussion of the measurement of photosensitivity, temperature dependence of photoemission, effect of cathode resistivity, response time, effect of initial velocity on transit time dispersion, ...
... Title : X-RAY PHOTOEMISSION STUDIES OF SUPERFICIALLY OXIDIZED CESIUM ANTIMONIDE PHOTOEMITTERS. Corporate Author : ...
... Accession Number : ADA049661. Title : Ultraviolet Photoemission Studies of Formaldehyde and Related Molecules Adsorbed on Ru(110). ...
... Date : MAY 1967. Pagination or Media Count : 319. Abstract : Photoemission studies of the electronic energy band structures of gallium arsenide ...
... Accession Number : AD0768409. Title : On the Feasibility of Observing Photoemission from Metal Contacts into Anthracene. ...
... Title : INVESTIGATION OF PHOTOEMISSION SOLAR ENERGY CONVERTERS. Corporate Author : RADIO CORP OF AMERICA LANCASTER PA. ...
... C. Photoemissive Detectors The IR radiation incident on the sensitive part of the detec- tor cell causes an electron stream due to photoemission. ...
... Title : Hydrogen Adsorption at Nb(100): Photoemission Evidence of Two-Stage Exchange Involving Subsurface States. ...
Experimental results are reported for an electrical device for direct conversion of methane into higher hydrocarbons. A microchannel plate is excited with electrons from a photoemissive source, and electron impact ionization of methane on the inner surfaces of the microchannels creates an ion feedback process. The resulting low-density ...
Electron-impact-ionization cross sections have been measured for the halogen atoms F, Cl, Br, and I from threshold to 200 eV. The absolute accuracy is +- 14%, except for F which is +- 20%. The halogen cross sections have shapes similar to those of the neighboring rare gases but are greater in magnitude. Simple semiclassical formulas of electron-impact ...
Electron-impact dissociation of CS2 has been studied by observation of the atomic spectral emission features in the range 115-170 nm. Absolute photoemission cross sections are presented over the complete wavelength range for an incident electron energy of 100 eV. As an example, the measured cross section of the strong C i emission at 165.7 nm, which is a ...
A high-resolution aberration-corrected photoemission electron microscope (PEEM3) will be installed on an undulator beamline at the Advanced Light Source at the Lawrence Berkeley National Laboratory. The aim of this instrument is to provide a substantial flux and resolution improvement by employing an electron mirror for correcting both the third-order spherical aberration and ...
This report is an attempt at a comprehensive compilation of currently available theoretical data on electron impact excitation of carbon and oxygen ions. It is designed to be of use primarily to theoretical atomic physicists, allowing them a broader than usual view of how various approximations compare. We do not attempt to place an estimate on the ...
Electron impact excitation cross sections have been calculated for transitions between terms of the ground configuration of neutral and ionized nitrogen and oxygen. The cross sections have been obtained by a distorted wave approximation and the accuracy o...
The valence-band discontinuities at various wurtzite GaN, AlN, and InN heterojunctions were measured by means of x-ray photoemission spectroscopy. A significant forward{endash}backward asymmetry was observed in the InN/GaN{endash}GaN/InN and InN/AlN{endash}AlN/InN heterojunctions. The asymmetry was understood as a piezoelectric strain effect. We report the valence band ...
Realistic electronic-structure calculations for correlated Mott insulators are notoriously difficult. Here we present an ab initio multiconfiguration scheme that adequately describes strong correlation effects involving Cu 3d and O 2p electrons in layered cuprates. In particular, the O 2p states giving rise to the Zhang-Rice band are explicitly considered. Renormalization effects due to nonlocal ...
We present density-functional theory calculations of the optical absorption spectra of silica glass for temperatures up to 2400�K. The calculated spectra exhibit exponential tails near the fundamental absorption edge that follow the Urbach rule in good agreement with experiments. We discuss the accuracy of our results by comparing to hybrid exchange correlation functionals. ...
Refinement of the photoionization method for measuring the reflectances of liquids and the investigation of benzene as a filling gas in the ion chambers are described. The optical functions of glycerol were determined to 24.4 eV. The improved accuracy of this measurement of reflectance by gas ionization permitted a more accurate value of the plasmon energy (22 eV) than that ...
This work compares a carefully designed experiment to measure photoemission with the predictions of three different codes (CEPXS/ONETRAN, TIGERP, and TIGER) for the complex bremsstrahlung spectra typical of very intense pulsed power x-ray generators. The Monte Carlo codes TIGER and TIGERP can calculate the net photon-induced electron emission but accurate results may require ...
The high-energy electron impact excitation cross sections are directly proportional to the generalized oscillator strengths (GOSs) of the target (an atom or molecule). In the present work, the GOSs of helium from the ground state to nS1 , nP1 , nD1 (n??) and adjacent continuum excited states are calculated by a modified R -matrix code within the ...
Contents: The Ge-Ag Interface at Room Temperatures: An Energy Dependent Photoemission Study; The Si(III)/Pt Interface at Room Temperature: An Synchrotron Radiation Photoemission Study, Photoemission Investigation on the Oxidation of Si(III)-Ag Interfaces ...
The electronic properties of Yb-based heavy fermions have been investigated by means of high resolution synchrotron radiation photoemission and compared with predictions of the Kondo model. The Yb heavy fermion photoemission spectra show massive disagreem...
Photoemission is a well established technique for the study of the electronic structure of atoms and solids. In particular, angle-resolved photoemission has been used extensively to map the band structure of clean and adsorbate covered surfaces, both meta...
A discussion of ultraviolet photoemission spectroscopy is given. A central theme which is applied to photoemission is that both theory and experiment profit from mutual interaction. Examples which are discussed include experimental and theoretical studies...
Temperature dependent properties of electronic states resulting from hydrogen adsorption of Nb(100) surfaces have been studied by photoemission spectroscopy using synchrotron radiation. The most prominent hydrogen induced feature in photoemission spectra ...
Effect of emitter thickness on the spectral shape of heterojunction interfacial workfunction of the spectral response of heterojunction interfacial workfunction internal photoemission detectors. The results increasingly impor- tant recently. The heterojunction interfacial-workfunction in- ternal photoemission HEIWIP
E-print Network
The electronic properties of Nb(100) are studied using angle-resolved photoemission. Several surface resonances are identified. One surface resonance exhibits significant enhancement of the photoemission cross section at the bulk plasma energy suggesting ...
This report is a review of theoretical methods and data for low-energy electron-impact excitation of atomic ions. It includes a comprehensive annotated bibliography of articles giving data on this subject. A brief discussion is given of the principal method employed, i.e., the approximations such as close coupling or distorted wave used in the solution of the electron-ion ...
... Abstract : Photoemission studies of the valence-band and core-level satellites of NiGa are presented. The valence-band satellite is resonantly ...
GaAs photoemissive yield spectrum analysis, discussing transition energies and energy band structure
... figure 2) images by scanning a photoemission; negative electron affinity, focused laser beam over the surface; this microscope's resolution is ...
Contents: The density of states of crystalline and amorphous Ge and Si; Photoemission investigation of amorphous Si and Ge; Investigation of the band edges of amorphous Ge and Si; Impurity electrons in amorphous Germanium a photoemission argument for the ...
A detailed experimental study is reported of electron photoemission at a solution-nitrogen interface by aqueous solutions of potassium or sodium ferrocyanide. Old work on this problem is briefly reviewed as well as similar studies with organic systems and...
... Accession Number : ADA074953. Title : Photoemission Studies of Time-Resolved Surface Reactions: Isothermal Desorption of Co from Ni (111). ...
... Accession Number : ADA070054. Title : Photoemission Studies of H2S, H2 and S Adsorbed on Ru(110): Evidence for an Adsorbed SH Species. ...
... Accession Number : ADA403013. Title : Laser Ionization Detection (LID) and Photoemissive (PE) Ion Mobility Spectrometry (IMS) Development. ...
... Accession Number : ADA327341. Title : High Resolution Photoemission Studies of Interfaces in High-Tc Superconductors. Descriptive Note : Rept. ...
... tool is high resolution soft x-ray photoemission spectroscopy (SXPS) using synchrotron radiation at the National Synchrotron Light Source (NSLS). ...
... Data was obtained by illuminating a plasma-cleaned sheet 5 Angstroms ... O'Shea, "A Photoemission Model For Low Work ... Function Coated Metal ... ...
... Accession Number : AD0858690. Title : Energy Angular Distribution of Photoemission from the Ag-O-Cs Photocathode. ...
This paper examines photoemission measurements of the alkaline Earth core levels of high-temperature
... Provides detailed search and analysis capabilities across ... A Simple Model of Soft X-Ray Photoemission. ... distribution of the electron emission current. ...
We discuss simulated energy and angular spectra of electrons lost to the vacuum chamber wall during beam-induced multipacting in SPS and LHC. Our simulations demonstrate that electron energies and impact angles are strongly correlated, and that the angular distribution can be modified by the beam magnetic field. The energy spectrum is found to be remarkably sensitive to changes in the bunch ...
The electron impact ionization of hydrogen, in the all-s-wave approximation, is treated by the improved distorted wave theory. The leading corrections to the distorted wave Born amplitude are calculated in the POST form, using simple variational trial functions. The localized virial conditions are imposed for the determination of nonlinear parameters, thus ...
Electron impact ionization cross sections are evaluated using a modified version [1] of the BELL formula [2] for a wide range of isoelectronic targets, ranging from Li to Ne targets with both the open and closed shell configurations. In this report the MBELL parameters are generalized for treating the orbital quantum numbers nl dependency; its ...
A model has been developed to calculate the ground state rotational populations of homonuclear diatomic molecules in kinetic gases, including the effects of electron-impact excitation, wall collisions, and gas feed rate. The equations are exact within the accuracy of the cross sections used and of the assumed equilibrating effect of wall collisions. It is found that the inflow ...
In this thesis, we argue in favour of photoemission as an in-situ characterization tool for the homo-epitaxial growth of GaAs. The first part, is concerned with the interpretation of the origin of the photoemission oscillations as first observed by J.N. E...
... Descriptors : *SODIUM, *FIELD EMISSION, *PHOTOELECTRIC EMISSION, *PHOTOVOLTAIC EFFECT, CRYSTALS, WORK FUNCTIONS ...
... have been obtained on the metal semiconductor interfaces. ... SUPERCONDUCTIVITY, *METALS, *SEMICONDUCTORS, *INTERFACES, ...
... POWER PRODUCTION, *SATURABLE REACTORS, *SOLAR RADIATION, DIELECTRICS, ETHYLENES, PHTHALATES, SIMULATION, SOLAR ...
