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in subjects: "Plasmons"

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Continuation of the Application of Parallel PIC Simulations to Laser and Electron Transport Through Plasmas Under Conditions Relevant to ICF and SBSS

In 2006/2007 we continued to study several issues related to underdense laser-plasma interactions. We have been studying the onset and saturation of Raman backscatter for NIF conditions, nonlinear plasma oscillations, and the two-plasmon decay instability.

Date: October 1, 2007

Creator: Mori, Warren B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Absolute two plasmon parametric decay of obliquely incident electromagnetic waves in an inhomogeneous plasma

The parametric decay of an electromagnetic wave into two electron plasma waves is considered. The electromagnetic wave is obliquely incident on the density gradient. The resulting analysis shows that the threshold for absolute instability decreases as the angle of incidence of the electromagnetic wave relative to the density gradient approaches 90/sup 0/. The importance of this result to laser fusion is discussed.

Date: October 1, 1976

Creator: Schuss, J. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Charge and Spin Transport in Dilute Magnetic Semiconductors

This proposal to the DOE outlines a three-year plan of research in theoretical and computational condensed-matter physics, with the aim of developing a microscopic theory for charge and spin dynamics in disordered materials with magnetic impurities. Important representatives of this class of materials are the dilute magnetic semiconductors (DMS), which have attracted great attention as a promising basis for spintronics devices. There is an intense experimental effort underway to study the trans… more

Date: July 23, 2009

Creator: Ullrich, Carsten A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Plasmon resonance absorption in layered structures of silver with periodic corrugation

Plasmon resonance absorption in periodically corrugated layered structures of silver was studied by the photoacoustic method. The layered structures were self-supporting and corrugated with a period of 1888 nm and amplitude varying from 6 to 12 nm, depending on the thickness. Experimental results of resonance absorption of 633-nm photons were analyzed in terms of the propagation and damping constants of coupled modes of surface plasmons. The coupling efficiency of incident photons to these mode… more

Date: January 1, 1987

Creator: Arakawa, E.T.; Inagaki, T. & Goudonnet, J.P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Use of Plasmon Coupling to Reveal the Dynamics of DNA Bending and Cleavage by Single EcoRV Restriction Enzymes

Pairs of Au nanoparticles have recently been proposed asplasmon rulers based on the dependence of their light scattering on theinterparticle distance. Preliminary work has suggested that plasmonrulers can be used to measure and monitor dynamic distance changes overthe 1 to 100nm length scale in biology. Here, we substantiate thatplasmon rulers can be used to effectively measure dynamical biophysicalprocesses by applying the ruler to a system that has been investigatedextensively using ensemble … more

Date: September 6, 2006

Creator: Reinhard, Bjorn; Sheikholeslami, Sassan; Mastroianni, Alexander; Alivisatos, A. Paul & Liphardt, Jan

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Surface and bulk excitations in condensed matter

In this lecture collective and single-particle electron excitations of solids will be discussed with emphasis on the properties of metallic and semiconducting materials. However, some of the general properties of long-wavelength collective modes to be discussed are valid for insulators as well, and some considerations apply to nuclear excitations such as optical or acoustical phonons, dipolar plasmons, etc. The concept of elementary excitations in solids, pioneered by Bohm and Pines almost 4 de… more

Date: January 1, 1988

Creator: Ritchie, R.H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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3 Dimensional radiation transport in dispersive media

In plasmas the collective motion of free electrons affects the propagation of radiation by bending the light ray trajectory. The closer the light wave frequency is to the electron plasma frequency in value, the more pronounced the effect. We will present the results of radiation transport calculations in 3 spatial dimensions in the refractive plasma environment and compare the calculation to one done where the ray bending has been neglected (straight line ray paths). We also present the numeric… more

Date: November 1, 1990

Creator: Mayle, R.W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Study of roughness-induced diffuse and specular reflectance at silver-air and silver-liquid interfaces. Final report, July 1, 1979-August 31, 1980

Results of an extended investigation of surface plasma-wave absorption and roughness-induced optical scattering from an interface of silver and air are described. In particular, the position of the surface plasma resonance minimum in reflectivity for a stochastically roughened metal silver surface has been studied as a function of a number of distinct roughness perturbations. In the case of a transparent liquid-silver boundary the frequency red shift of the resonance minimum has been determined… more

Date: July 1, 1980

Creator: Sari, S.O.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Confinement of low-energy electrons near metallic surfaces for plasmon generation

A novel technique is used in studying the energy loss spectrum of aloof (nontouching) electrons with surfaces. Metallic foils perforated by microchannels restrict the maximum impact parameter to the channel radius (20 to 200 nm). The passage of electrons (20 to 2000 eV) near the cylinder walls results in prominent energy-loss structure. In silver, a resonance loss peak at 3.5 to 3.6 eV is attributed to the formation of surface plasmons on the silver channels. The problem is modeled by a classic… more

Date: January 1, 1984

Creator: Warmack, R. J.; Ferrell, T. L.; Ritchie, R. H.; Becker, R. S.; Mamola, K. C.; Buncick, M. C. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Nanocrystal Bioassembly: Asymmetry, Proximity, and Enzymatic Manipulation

Research at the interface between biomolecules and inorganic nanocrystals has resulted in a great number of new discoveries. In part this arises from the synergistic duality of the system: biomolecules may act as self-assembly agents for organizing inorganic nanocrystals into functional materials; alternatively, nanocrystals may act as microscopic or spectroscopic labels for elucidating the behavior of complex biomolecular systems. However, success in either of these functions relies heavily up… more

Date: May 1, 2008

Creator: Claridge, Shelley A

Item Type: Thesis or Dissertation

Partner: UNT Libraries Government Documents Department

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Inelastic Electron Scattering From Surfaces

This report contains highlights of accomplishments of the past year, for the University of California, Irvine and the University of Wisconsin, Milwaukee collaboration on surface excitations, and their interactions with low energy electrons. In addition, we present a summary of future research to be carried out in the coming grant year.

Date: January 1, 1991

Creator: Tong, S. Y. & Mills, D. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Near-Infrared Localized Surface Plasmon Resonances Arising from Free Carriers in Doped Quantum Dots

Quantum confinement of electronic wavefunctions in semiconductor quantum dots (QDs) yields discrete atom-like and tunable electronic levels, thereby allowing the engineering of excitation and emission spectra. Metal nanoparticles, on the other hand, display strong resonant interactions with light from localized surface plasmon resonance (LSPR) oscillations of free carriers, resulting in enhanced and geometrically tunable absorption and scattering resonances. The complementary attributes of thes… more

Date: October 12, 2010

Creator: Jain, Prashant K.; Luther, Joey; Ewers, Trevor & Alivisatos, A. Paul

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Determinations of lattice and electronic structures of solids by electron scattering. Progress report, July 1, 1979-June 30, 1980. [Dept. of Physics, Washington Univ. , St. Louis]

The design and fabrication of all the major components of the system were completed. The electronics were assembled and tested. The spectrometer was assembled and tested, with first full operation of the facility before June 30, 1980. Techniques and facilities for sample preparation, sample characterization, data gathering, and data analysis are functional. Operation of the electron microscope and the electron detector, and ray-tracing analysis of the spectrometer, produced results sufficient t… more

Date: January 1, 1980

Creator: Gibbons, P.C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Energy losses to surface plasmons by charged particles

The theory of charged particle energy loss to the surface plasmon field is reviewed for a swift charged particle incident on a model metallic system. The expected energy loss is estimated for some representative cases. (GHT)

Date: January 1, 1982

Creator: Ritchie, R.H. & Ashley, J.C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Study of semiconductor valence plasmon line shapes via electron energy-loss spectroscopy in the transmission electron microscope

Electron energy-loss spectra of the semiconductors Si, AlAs, GaAs, InAs, InP, and Ge are examined in detail in the regime of outer-shell and plasmon energy losses (0--100eV). Particular emphasis is placed on modeling and analyzing the shapes of the bulk valence plasmon lines. A line shape model based on early work by Froehlich is derived and compared to single-scattering probability distributions extracted from the measured spectra. Model and data are found to be in excellent agreement, thus po… more

Date: November 1, 1988

Creator: Kundmann, M.K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Collective aspects of charged particle track structure

A plasmon generated by a swift charged particle constitutes a coherent excitation about the particle track. We discuss the representation of collective modes in impact parameter space when created by a swift ion or a fast electron, and the decay of these modes into localized excitations. Several alternative spatial representations are considered. We show that the high spatial resolution found in secondary electron emission measurements with scanning electron microscopy is consistent with the ex… more

Date: January 1, 1989

Creator: Basbas, G. (Physical Review Letters, Ridge, NY (USA)); Howie, A. (Cambridge Univ. (UK). Cavendish Lab.) & Ritchie, R. H. (Oak Ridge National Lab., TN (USA) Tennessee Univ., Knoxville, TN (USA). Dept. of Physics)

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Semiclassical eigenenergies in the wake of fast ions in solids

We compare the semiclassical and quantum mechanical eigenenergies of an electron in the wake of a fast, highly charged ion traversing a solid. The classical dynamics of this system shows a transition from regular to chaotic motion as a function of the binding energy. The transition can also be seen in the quantal spectra. We find evidence for a connection between bifurcation of tori and disorder in the energy level sequences. 21 refs., 4 figs.

Date: January 1, 1990

Creator: Mueller, J.; Burgdoerfer, J. & Noid, D.W. (Tennessee Univ., Knoxville, TN (USA). Dept. of Physics Oak Ridge National Lab., TN (USA))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Thomson Scattering Measurements of Plasma Dynamics

The authors propose to investigate the dynamics of plasmas in the warm dense matter (WDM) regime on ultra-short time scales. Accessible plasma conditions are in the density range of n = 10{sup 20} - 10{sup 23} cm{sup -3} and at moderate temperatures of T = 1 - 20 eV. These plasmas are of importance for laboratory astrophysics, high energy density science and inertial confinement fusion. They are characterized by a coupling parameter of {Lambda} {approx}> 1, where electromagnetic interactions… more

Date: March 29, 2006

Creator: Holl, A; Redmer, R; Tschentscher, T; Toleikis, S; Forster, E; Cao, L et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Electronic band structure and photoemission: A review and projection

A brief review of electronic-structure calculations in solids, as a means of interpreting photoemission spectra, is presented. The calculations are, in general, of three types: ordinary one-electron-like band structures, which apply to bulk solids and are the basis of all other calculations; surface modified calculations, which take into account, self-consistently if at all possible, the presence of a vacuum-solid interface and of the electronic modifications caused thereby; and many-body calcu… more

Date: September 1, 1987

Creator: Falicov, L.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radiative decay of surface plasmons on nonspherical silver particles

We have studied the radiation emitted by electron-bombarded silver particles. Electron micrographs have shown that the particles, obtained by heating thin (5 nm) silver films, were oblate (flattened) with minor axes aligned along the substrate normal. The characteristic wavelength obtained by bombarding these particles with 15-keV electrons was found to vary with angle of photon emission. We have modeled this wavelength shift as a result of the mixture of radiation from dipole and quadrupole su… more

Date: January 1, 1982

Creator: Little, J. W.; Ferrell, T. L.; Callcott, T. A. & Arakawa, E. T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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The approach to equilibrium in a quark-gluon plasma

The basic questions to be addressed in this paper are: How does the quark-gluon plasma, once formed in heavy-ion collisions, approach equilibrium. What are the basic equilibrium time scales - how do they compare with the plasma lifetime before hadronization and freeze-out set in. In particular, how do the strong color anisotropies, which are presumably present in the initial formation stage disappear and how fast, if at all, do the color degrees of freedom attain local equilibrium. The approach… more

Date: January 1, 1987

Creator: Heinz, U.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Third harmonic generation with ultra-high intensity laser pulses

When an intense, plane-polarized, laser pulse interacts with a plasma, the relativistic nonlinearities induce a third harmonic polarization. A phase-locked growth of a third harmonic wave can take place, but the differences between the nonlinear dispersion of the pump and driven waves leads to a rapid unlocking, resulting in a saturation. What becomes third harmonic amplitude oscillations are identified here, and the nonlinear phase velocity and the renormalized electron mass due to plasmon scr… more

Date: April 1, 1992

Creator: Rax, J. M. & Fisch, N. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Dynamical image charge effects on convoy electron emission from solid surfaces

We analyze surface effects on the spectrum of convoy electrons emitted from solids in close association with fast highly charged ions. Three competing mechanisms have been identified: Deceleration by the surface barrier, acceleration by the repulsive dynamical image force, and energy loss due to surface plasmon generation. The resulting energy shift is significantly reduced compared to the value for the barrier height for a jellium surface. We also give estimates for the probability for non-adi… more

Date: January 1, 1986

Creator: Burgdoerfer, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Determinations of lattice and electronic structures of solids by electron scattering. Progress report

A discussion is presented of the final results of a study of the causes of finite widths of plasmons as observed in energy loss spectra. The performance of the imaging spectrometer is described, along with methods used for the analysis of EXAFS data and the tests made of those methods. (GHT)

Date: March 4, 1981

Creator: Gibbons, P.C.

Item Type: Report

Partner: UNT Libraries Government Documents Department