Remark on polarization effects in small angle electron scattering by helium atoms in a CO2 laser field

1995 ◽  
Vol 203 (4) ◽  
pp. 203-208 ◽  
Author(s):  
S Varró ◽  
F Ehlotzky
Keyword(s):  
Co2 Laser ◽  
Electron Scattering ◽  
Small Angle ◽  
Laser Field ◽  
Polarization Effects ◽  
Helium Atoms

Small Angle Electron Scattering From Vacuum Condensed Metallic Films

1968 ◽  
Vol 26 ◽  
pp. 380-381
Author(s):  
J. Silcox ◽  
R. H. Wade
Keyword(s):  
Electron Scattering ◽  
Small Angle ◽  
Ring Structure ◽  
Two Dimensional ◽  
Metallic Films ◽  
Micro Structure ◽  
Angle Scattering ◽  
The Fourier Transform ◽  
Source Of Information ◽  
Kinematical Theory

Recent work has drawn attention to the possibilities that small angle electron scattering offers as a source of information about the micro-structure of vacuum condensed films. In particular, this serves as a good detector of discontinuities within the films. A review of a kinematical theory describing the small angle scattering from a thin film composed of discrete particles packed close together will be presented. Such a model could be represented by a set of cylinders packed side by side in a two dimensional fluid-like array, the axis of the cylinders being normal to the film and the length of the cylinders becoming the thickness of the film. The Fourier transform of such an array can be regarded as a ring structure around the central beam in the plane of the film with the usual thickness transform in a direction normal to the film. The intensity profile across the ring structure is related to the radial distribution function of the spacing between cylinders.

Small-Angle Electron Scattering (SAES) of Polymers

1985 ◽  
Vol 43 ◽  
pp. 78-79
Author(s):  
Ralph Oralor ◽  
Pamela Lloyd ◽  
Satish Kumar ◽  
W. W. Adams
Keyword(s):  
Electron Scattering ◽  
Small Angle ◽  
Angular Resolution ◽  
Structural Features ◽  
Objective Lens ◽  
High Angular Resolution ◽  
Push Button ◽  
First Case ◽  
Diffraction Mode ◽  
Very High

Small angle electron scattering (SAES) has been used to study structural features of up to several thousand angstroms in polymers, as well as in metals. SAES may be done either in (a) long camera mode by switching off the objective lens current or in (b) selected area diffraction mode. In the first case very high camera lengths (up to 7Ø meters on JEOL 1Ø ØCX) and high angular resolution can be obtained, while in the second case smaller camera lengths (approximately up to 3.6 meters on JEOL 1Ø ØCX) and lower angular resolution is obtainable. We conducted our SAES studies on JEOL 1ØØCX which can be switched to either mode with a push button as a standard feature.

Small-angle electron scattering by formaldehyde and ketene: Effects of electron correlation and chemical binding

1992 ◽  
Vol 43 (5) ◽  
pp. 701-712 ◽  
Author(s):  
Yorihiko Sasaki ◽  
Hiroshi Takeuchi ◽  
Shigehiro Konaka ◽  
Masao Kimura
Keyword(s):  
Electron Scattering ◽  
Small Angle ◽  
Electron Correlation ◽  
Chemical Binding

scholarly journals Laser-assisted two-color two-photon double ionization of helium atoms

2021 ◽  
Author(s):  
Zhizhen Zhu ◽  
Kai Liu ◽  
Xiaofan Zhang ◽  
Ye Li ◽  
Feng Wang ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Laser Field ◽  
Double Ionization ◽  
Destructive Interference ◽  
Energy Distributions ◽  
Laser Photon ◽  
One Dimensional ◽  
Helium Atoms ◽  
Two Photon ◽  
Kinetic Energy Distributions

Abstract Correlated momentum and kinetic energy distributions of two photoelectrons in laser-assisted two-color two-photon double ionization of helium are investigated by numerically solving a one-plus-one dimensional time-dependent Schr\"{o}dinger equation (TDSE). We find that the weak assisting laser field can act as an energy transferring field, resulting in burst of double ionization. More importantly, the participation of the laser photon into the double ionization reshapes the correlation patterns in the momentum and kinetic energy distributions. The laser photon can be absorbed by any one of the two electrons, providing two channels that induces destructive interference in the correlated momentum and kinetic energy distributions, which is never found in previous work.

Electron impact excitation of He 21P in the presence of a nonresonant laser field

1993 ◽  
Vol 71 (7-8) ◽  
pp. 326-333 ◽  
Author(s):  
B. Wallbank ◽  
J. K. Holmes ◽  
A. Weingartshofer
Keyword(s):  
Carbon Dioxide ◽  
Cross Sections ◽  
Differential Cross ◽  
Laser Field ◽  
Carbon Dioxide Laser ◽  
Impact Excitation ◽  
Incident Electron Energy ◽  
Electron Impact Excitation ◽  
Helium Atoms ◽  
Simultaneous Absorption

We report experimental differential cross sections for inelastic scattering of electrons from helium atoms in the presence of an intense (~108 W cm−2) carbon dioxide laser. The cross sections for excitation of the 21P state of helium with the simultaneous absorption or emission of one laser quantum were measured over the incident electron energy range of 36–70 eV and scattering angles of 13–31°.

Longitudinal magnetoresistance in silver and copper between 4.2 and 35 °K

1967 ◽  
Vol 302 (1468) ◽  
pp. 83-98 ◽  
Keyword(s):  
Relaxation Time ◽  
Electron Scattering ◽  
Small Angle ◽  
Time Approximation ◽  
Long Wavelength ◽  
Relaxation Time Approximation ◽  
Angle Scattering ◽  
Different Types ◽  
Pure Single Crystal ◽  
Longitudinal Magnetoresistance

Longitudinal magnetoresistance has been measured in a number of single crystals of silver and one very pure single crystal of copper in fields up to 65 kG and at temperatures between 4.2 and 35 °K. The purpose of the work has been to investigate the effects of different types of electron scattering, in particular small angle scattering. It has been found that at 4.2 °K impure crystals obey the relaxation time approximation fairly well, whereas crystals that have been purified (by oxidation at 800 °C) do not. Above 4.2 °K, the addition of long wavelength phonons has caused the magnetoresistance to increase substantially, as predicted by Pippard (1964), but agreement with Pippard’s theory is only qualitative. To account for the results a more detailed treatment of the scattering is required.

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