Sources of electron energy in weakly ionized expansions of nitrogen
Sources of electron energy in weakly ionized expansions of nitrogen
Dunn, M. G.↗
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Low-energy electron diffraction intensities - Comparison between theory and experiment
Low energy electron beam diffraction, calculating intensity as wavelength function
Hofmann, F.↗
Extended fine structures in the electron energy loss spectrum of InAs
The possibility of using electron energy loss fine structure (EELFS) for the characterization of thin pseudomorphic quantum wells of InAs and GaAs(100) is investigated. It is shown that the EELFS technique can yield reliable radial distribution functions for bulk InAs, provided beam-induced sample degradation is controlled stringently. Additional improvements in the data collection procedures, including better control of the sample condition, are required as well as more detailed work on separating contributions from multiple edges in the data analysis.
Schowengerdt, F. D.↗
Free-Free Transitions of the e-H System Inside a Dense Plasma Irradiated by a Laser Field at Very Low Incident-Electron Energies
The free-free transition is studied for an electron-hydrogen atom in ground state when a low-energy electron (external) is injected into hydrogenic plasma in the presence of an external homogenous, monochromatic, and linearly polarized laser field. The effect of plasma screening is considered in the Debye-Huckel approximation. The calculations are performed in the soft photon limit. The incident electron is considered to be dressed by the laser field in a nonperturbative manner by choosing the Volkov solutions in both the initial and final channels. The space part of the scattering wave function for the electron is solved numerically by taking into account the electron exchange. The laser-assisted differential and total cross sections are calculated for single-photon absorption or emission and no-photon exchange in the soft photon limit, the laser intensity being much less than the atomic field intensity. The calculations have been carried out for various values of Debye parameter, ranging from 0.005 to 0.12. A strong suppression is noted in the laser-assisted cross sections as compared to the field-free situation. A significant difference is noted for the singlet and triplet cross sections. The suppression is much more in the triplet states.
Bhatia, A. K.↗
Free-Free Transitions in the Presence of Laser Fields and Debye Potential at Very Low Incident Electron Energies
We study the free-free transition in electron-helium ion in the ground state and embedded in a Debye potential in the presence of an external laser field at very low incident electron energies. The laser field is treated classically while the collision dynamics is treated quantum mechanically. The laser field is chosen as monochromatic, linearly polarized and homogeneous. The incident electron is considered to be dressed by the laser field in a nonperturbative manner by choosing Volkov wave function for it. The scattering wave function for the incident electron on the target embedded in a Debye potential is solved numerically by taking into account the effect of electron exchange. We calculate the laser-assisted differential and total cross sections for free-free transition for absorption/emission of a single photon or no photon exchange. The results will be presented at the conference.
Bhatia, Anand↗
Low-energy electron transport with the method of discrete ordinates
The one-dimensional discrete ordinates code ANISN was adapted to transport low energy (a few MeV) electrons. Calculated results obtained with ANISN were compared with experimental data for transmitted electron energy and angular distribution data for electrons normally incident on aluminum slabs of various thicknesses. The calculated and experimental results are in good agreement for a thin slab (0.2 of the electron range), but not for the thicker slabs (0.6 of the electron range). Calculated results obtained with ANISN were also compared with results obtained using Monte Carlo methods.
Bartine, D. E.↗
Effects of a simulated high energy electron space environment on the ultraviolet transmittance of optical materials between 1050 and 3000 A
Effects of simulated high energy electron space environment on ultraviolet transmittance of optical materials
HIGH ENERGY ELECTRON↗
Electron energy distribution produced by beam-plasma discharge
In an investigation of a beam-plasma discharge (BPD), the electron energy distribution of an electron beam moving through a partially ionized gas is analyzed. Among other results, it is found that the occurrence of BPD heats the initially cold electron beam from the accelerator. The directional intensity of electrons measured outside the beam core indicates that most particles suffer a single scattering in energy and pitch angle. At low currents this result is expected as beam particles collide with the neutral atmosphere, while in BPD the majority of particles is determined to still undergo a single scattering near the original beam core. The extended energy spectra at various beam currents show two rather distinct plasma populations, one centered at the initial beam energy (approximately 1500 eV) and the other at approximately 150 eV.
Anderson, H. R.↗
Low-energy electrons measured on IMP 2.
Integral spectrum for low-energy electrons measured with detailed definition of temperature and number density by IMP II
SATELLITE MEASUREMENT↗
Initial Observations of Low-energy Electrons in the Earth's Magnetosphere with OGO 3
Low energy electrons in earth magnetosphere observed by OGO III
ELECTRON↗
Elastic scattering of low-energy electrons from molecular hydrogen.
Elastic scattering cross section of low energy electrons calculated by continuum Hartree-Fock equations
Taylor, H. S.↗
Electron bremsstrahlung produced in thick targets at incident electron energies of 0.2, 1.0, 2.0, and 2.8 MeV, part 3
Electron bremsstrahlung produced in thick targets at incident electron energies of 0.2, 1.0, 2.0, and 2.8 MeV
Dance, W. E.↗
Elastic scattering of low-energy electrons from metastable helium.
Elastic scattering cross section for low energy electrons on metastable He atoms, using polarized orbital method
Callaway, J.↗
Emission of high-energy electrons during alloy- evaporation processes on hot metal filaments.
High energy electrons emission during alloy evaporation on hot metal filaments used for thin film deposition
Hoenig, S. A.↗
Theory of surface plasmon excitation in low- energy electron diffraction and in photoemission
Inelastic scattering of electrons by surface plasma oscillation for low energy electron diffraction and photoemission, interpreting surface plasmon excitation
Cohen, M. H.↗
Comparative characteristics of electron energy spectrum in PIG and arc type discharge plasmas
The electron distribution functions relative to the velocity component directed along the magnetic field are compared for PIG and arc type discharges. The identity of these functions for the plasma region pierced by the primary electron beam and their difference in the peripheral part of the discharge are shown. It is concluded that the electron distribution function in the PIG type discharge is formed during one transit of the primary electron through the discharge gap. The mechanisms of electron energy spectrum formation in both the axis region and the peripheral region of the discharge are discussed.
Romanyuk, L. I.↗
Calculating the X-Ray Fluorescence from the Planet Mercury Due to High-Energy Electrons
The least-studied terrestrial planet is Mercury due to its proximity to the Sun, which makes telescopic observations and spacecraft encounters difficult. Our lack of knowledge about Mercury should change in the near future due to the recent launching of MESSENGER, a Mercury orbiter. Another mission (BepiColombo) is currently being planned. The x-ray spectrometer on MESSENGER (and planned for BepiColombo) can characterize the elemental composition of a planetary surface by measuring emitted fluorescent x-rays. If electrons are ejected from an atom s inner shell by interaction with energetic particles such as photons, electrons, or ions, electrons from an outer shell can transfer to the inner shell. Characteristic x-rays are then emitted with energies that are the difference between the binding energy of the ion in its excited state and that of the ion in its ground state. Because each element has a unique set of energy levels, each element emits x-rays at a unique set of energies. Electrons and ions usually do not have the needed flux at high energies to cause significant x-ray fluorescence on most planetary bodies. This is not the case for Mercury where high-energy particles were detected during the Mariner 10 flybys. Mercury has an intrinsic magnetic field that deflects the solar wind, resulting in a bow shock in the solar wind and a magnetospheric cavity. Electrons and ions accelerated in the magnetosphere tend to follow its magnetic field lines and can impact the surface on Mercury s dark side Modeling has been done to determine if x-ray fluorescence resulting from the impact of high-energy electrons accelerated in Mercury's magnetosphere can be detected by MESSENGER. Our goal is to understand how much bulk chemical information can be obtained from x-ray fluorescence measurements on the dark side of Mercury.
Burbine, T. H.↗
On the anticorrelation of the electric field and peak electron energy within an auroral arc
The present investigation is concerned with an example of a strongly anticorrelated electric field and particle precipitation, taking into account an application of an extended version of the model of Evans et al. (1977) to the data. A striking feature of the data reported is the high degree of anticorrelation between electric field strength and peak precipitating electron energy. A simple model consisting of a constant current traversing a region in which the conductivities increase in proportion to ionospheric energy deposition provides a qualitative explanation of the observations. However, when the effects of neutral winds, ionization transport, Hall currents, and arc motion, and the nonlinearity of the relationship between peak precipitating electron energy and equilibrium are considered, the conclusions become less clear.
Mallinckrodt, A. J.↗