Energy dependences of (nγ)- and (np)-components of neutron fluxes from “γ-quantum-photoneutron” converters within the 14 – 24 MeV Electron energy range of an M – 30 microtron

Using high resolution electron energy loss spectroscopy (HREELS) the surface phonon dispersion of graphite has been determined in the Γ K direction over the whole energy range and the whole Brillouin zone. By depositing lanthanum and annealing we prepared a GIC-like phase which grows on top of an intermediate carbide. The phonon dispersion of this phase shows the same modes as graphite, but the optical ones are softened and the acoustical ones are stiffened. This is described within a Born-von Karman model. The evolution of the phonon dispersion gives a first hint that the GIC-like phase may develop in two stages: first a monolayer graphite on top of the carbide and then the very thin GIC layer.

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The dielectric constant of TCNQ single crystals as deduced by reflection electron energy loss spectroscopy

Journal of Materials Research ◽

10.1557/jmr.1993.2627 ◽

1993 ◽

Vol 8 (10) ◽

pp. 2627-2633 ◽

Cited By ~ 16

Author(s):

G. Mondio ◽

F. Neri ◽

G. Curró ◽

S. Patané ◽

G. Compagnini

Keyword(s):

Dielectric Constant ◽

Energy Loss ◽

Energy Range ◽

Single Crystals ◽

Electron Energy ◽

Electron Energy Loss Spectroscopy ◽

Incidence Angle ◽

Low Energy ◽

Wide Energy Range ◽

Electron Energy Loss

The dielectric constant of tetracyanoquinodimethane (TCNQ) single crystals has been obtained by reflection electron energy loss spectroscopy (REELS) over the 0–60 eV energy range, using primary electron energies ranging from 0.5 to 1.5 keV at an incidence angle of about 40°. A self-consistent method is discussed concerning the evaluation of the surface and bulk contributions to the loss spectra. As a result, for the first time, the Im(−1/∊) function and the dielectric constant of TCNQ have been deduced in such a wide energy range. According to the results obtained by other authors, the low-energy loss spectral profile is characterized by two main structures ascribed to the π → π∗ dipole-allowed transitions located at about 3.5 and 6.5 eV while, at higher energy loss, the π + σ plasmon, centered at about 21.5 eV, dominates the spectrum. The differences among the spectra taken at different primary energies are interpreted as due only to surface effects, more evident in the low-energy-loss spectral region. The results are in good agreement with those obtained by recent transmission-mode (TEELS) experiments.

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The reaction 7Li(e, 3H)4He,e′ between 6 and 15 MeV

Canadian Journal of Physics ◽

10.1139/p77-036 ◽

1977 ◽

Vol 55 (3) ◽

pp. 252-253 ◽

Cited By ~ 5

Author(s):

M. K. Leung ◽

J. J. Murphy II ◽

Y. M. Shin ◽

D. M. Skopik

Keyword(s):

Energy Range ◽

Electron Energy ◽

Cross Sections ◽

Electric Dipole ◽

Incident Electron ◽

Incident Electron Energy ◽

Sum Rule

Tritons resulting from the electrodisintegration of 7Li have been measured at 90° for an incident electron energy of 23.8 MeV over an energy range which ensured that only tritons emitted in the two-body channel were detected. The electrodisintegration cross sections were converted to equivalent photodisintegration data and compared to earlier results. Large discrepancies are observed. It is found that the (γ,3H) channel contributes appreciably to the electric dipole sum rule for 7Li.

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HgCl B2Σ+1/2 formation by low-energy electron impact dissociation of HgCl2 and(or) CH3HgCl molecules: applications to HgCl (B → X) laser

Canadian Journal of Physics ◽

10.1139/p90-023 ◽

1990 ◽

Vol 68 (2) ◽

pp. 166-169 ◽

Cited By ~ 1

Author(s):

Mohammad F. Mahmood

Keyword(s):

Energy Range ◽

Electron Energy ◽

Cross Sections ◽

Band System ◽

Low Energy ◽

Dissociative Excitation ◽

Intense Band ◽

Electron Impact Dissociation ◽

Low Energy Electrons ◽

Low Energy Electron

An investigation was made of the process of dissociative excitation of a HgCl radical in the B2Σ+1/2 state due to collisions of low-energy electrons with HgCl2 and CH3HgCl molecules. Using the most intense band of the B2Σ+1/2 – X2Σ+1/2 system of the HgCl radical at 557 nm that corresponds to the ν′ = 0 to ν″ = 22 transition, emission cross sections were measured in the electron energy range 1–100 eV. The threshold electron energy for the observation of the B2Σ+1/2 – X2Σ+1/2 band system has been determined to be 7.0 and 8.0 eV for HgCl2 and CH3HgCl molecules, respectively.

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