Imaging intramolecular hydrogen migration with time- and momentum-resolved photoelectron diffraction

Imaging ultrafast hydrogen migration with few- or sub-femtosecond time resolution is a challenge for ultrafast spectroscopy due to the lightness and small scattering cross section of the moving hydrogen atom....

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Elliptically polarized laser assisted elastic electron-hydrogen atom collision and differential scattering cross-section

Himalayan Physics ◽

10.3126/hp.v9i01.40205 ◽

2020 ◽

pp. 93-102

Author(s):

Kishori Yadav ◽

S.P. Gupta ◽

J.J. Nakarmi

Keyword(s):

Hydrogen Atom ◽

Kinetic Energy ◽

Cross Section ◽

Laser Field ◽

High Energy ◽

Scattering Cross Section ◽

Hydrogen Atoms ◽

Differential Scattering Cross Section ◽

Scattering Cross ◽

Cross Section Area

In the present study, we have investigated scattering of an electron by hydrogen atoms in the presence of the elliptical polarized laser ﬁeld. We have discussed the polarization effect of laser ﬁeld on hydrogen atom and effect of the resulted polarized potential on differential scattering cross-section is studied. We assume the scattered electrons having kinetic energy (~3000 eV) and laser ﬁeld of moderate ﬁeld strength because it is permitted to treat the scattering process in ﬁrst Born approximation and the scattering electron was described by Volkov wave function. We found that the differential scattering cross-section area increases with the increase of the kinetic energy of the incident electron and there is no effect of changing the value of polarizing angle on the differential cross-section with kinetic energy. We observed that differential scattering cross-section in elliptical polarization in the high energy region depends upon the laser intensity and the incident energy for a linearly polarized ﬁeld.

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Mass Determination by Direct Measurement of Electron Scattering

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100114827 ◽

1975 ◽

Vol 33 ◽

pp. 240-241

Author(s):

M. K. Lamvik ◽

A. V. Crewe

Keyword(s):

Cross Section ◽

Electron Scattering ◽

Mass Density ◽

Variable Mass ◽

Scattering Cross Section ◽

Mass Determination ◽

Number Density ◽

Cross Sectional ◽

Thin Slice ◽

Scattering Cross

If a molecule or atom of material has molecular weight A, the number density of such units is given by n=Nρ/A, where N is Avogadro's number and ρ is the mass density of the material. The amount of scattering from each unit can be written by assigning an imaginary cross-sectional area σ to each unit. If the current I0 is incident on a thin slice of material of thickness z and the current I remains unscattered, then the scattering cross-section σ is defined by I=IOnσz. For a specimen that is not thin, the definition must be applied to each imaginary thin slice and the result I/I0 =exp(-nσz) is obtained by integrating over the whole thickness. It is useful to separate the variable mass-thickness w=ρz from the other factors to yield I/I0 =exp(-sw), where s=Nσ/A is the scattering cross-section per unit mass.

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