Two-target-atom model for calculating cross sections of direct recoils

1991 ◽  
Vol 255 (1-2) ◽  
pp. 127-134 ◽  
Author(s):  
Shiladitya Chakraborty ◽  
R. Stanley Williams
Keyword(s):  
Cross Sections ◽  
Target Atom ◽  
Atom Model

Two-target-atom model for calculating cross sections of direct recoils

1991 ◽  
Vol 255 (1-2) ◽  
pp. A506
Author(s):  
Shiladitya Chaudhury ◽  
R.Stanley Williams
Keyword(s):  
Cross Sections ◽  
Target Atom ◽  
Atom Model

Gaseous and surface reactions involving helium metastable atoms and resonance photons

1957 ◽  
Vol 241 (1225) ◽  
pp. 270-282 ◽  
Keyword(s):  
Cross Sections ◽  
Gold Surface ◽  
Target Atom ◽  
Photon Flux ◽  
Total Cross Sections ◽  
Metastable Helium ◽  
Helium Atoms ◽  
Atom Flux ◽  
Collision Chamber ◽  
Argon Ions

The absolute electron yield ( γ M ) for He (2 3 S ) metastable atoms incident on a gold surface has been measured. The method requires passage of a metastable atom flux through a collision chamber containing argon and thence to the gold surface. From observations on the current of argon ions arising from collisions of the type He (2 3 S ) + A → He + A + + e , together with measurements of the electron emission from the gold surface, γ M may be determined. The total cross-sections for collisions between metastable helium atoms and He, Ne, A and K have been measured and in the asymmetrical cases are observed to rise linearly with increasing atomic number of the target atom. Some collisions involving helium resonance radiation have also been studied. In particular, the photo-electric yield from the gold surface has been determined together with the attenuation of the photon flux in passage through certain noble gases.

scholarly journals Вероятность процессов захвата электронов у атомов аргона ионами -=SUP=-3-=/SUP=-Не-=SUP=-2+-=/SUP=- при различных параметрах удара

2019 ◽  
Vol 89 (3) ◽  
pp. 342
Author(s):  
А.А. Басалаев ◽  
М.Н. Панов
Keyword(s):  
Cross Sections ◽  
Particle Interaction ◽  
Target Atom ◽  
Interaction Potentials ◽  
Atomic Particle ◽  
Total Cross Sections ◽  
Singly Charged ◽  
Scattering Cross Sections ◽  
The Impact ◽  
Argon Ion

AbstractWe have measured the absolute values of total cross sections of capture of one and two electrons by He^2+ ions from argon atoms. The differential scattering cross sections have been determined for fast atoms and singly charged helium ions formed in each of these processes (without and with additional ionization of the formed slow argon ion). Measurements have been taken for He^2+ ions with kinetic energy of 6 keV in scattering angle range 0–2.5°. Based on the measured differential cross sections using different model atomic particle interaction potentials, we have calculated the cross sections of these processes as functions of the impact parameter. The probabilities of realization of these processes with electron density distribution in different shells in the target atom have been compared. The applicability of the expressions for the screened Coulomb interaction potentials in the description of scattering of particles that have captured electrons has been demonstrated.

scholarly journals Volume correction factor in electron-Indium atom scattering experiments

2008 ◽  
Vol 6 (1) ◽  
pp. 119-125 ◽  
Author(s):  
M.S. Rabasovic ◽  
S.D. Tosic ◽  
V. Pejcev ◽  
D. Sevic ◽  
D.M. Filipovic ◽  
...  
Keyword(s):  
Correction Factor ◽  
Cross Sections ◽  
Target Atom ◽  
Indium Atom ◽  
Measured Signal ◽  
Atom Beam ◽  
Experimental Conditions ◽  
Volume Correction ◽  
Interaction Volume ◽  
Atom Scattering

In crossed electron beam - Indium atom beam scattering experiments the measured signal arises from a spatial region (the 'interaction volume') defined by the overlap of the electron and target atom beam and the view cone of the detector. The exchange of the interaction volume with the scattering angle, named a volume correction factor is discussed. The approach of R. T. Brinkmann and S. Trajmar (J. Phys. E 14, 245-254 (1981)) is adopted for our experimental conditions to determine the volume correction factor and accordingly to transfer angular distributions of scattered electrons to relative differential cross sections.

scholarly journals GENETIC PROGRAMMING APPROACH FOR ELECTRON-ALKALI-METAL ATOM COLLISIONS

2006 ◽  
Vol 20 (32) ◽  
pp. 5463-5471 ◽  
Author(s):  
SALAH YASEEN EL-BAKRY ◽  
AMR RADI
Keyword(s):  
Experimental Data ◽  
Genetic Programming ◽  
Cross Sections ◽  
Alkali Metal Atom ◽  
Intermediate Energy ◽  
Target Atom ◽  
Programming Approach ◽  
Dipole Polarizability ◽  
Total Cross Sections ◽  
Alkali Atoms

New technique is presented for modeling the total cross sections of electron scattering by Na, K, Rb and Cs atoms in the low and intermediate energy regions. The calculations have been performed in the framework of genetic programming (GP) technique. The GP has been running based on the experimental data of the total collisional cross sections to produce the total cross sections for each target atom. The incident energy and atomic number as well as the static dipole polarizability have been used as input variables to find the functions that describe the total collisional cross sections of the scattering of electrons by alkali atoms. The experimental, calculated and predicted total collisional cross sections are compared. The discovered functions show a good match to the experimental data.

scholarly journals Calculations of radiation opacity for high Z elements

1990 ◽  
Vol 8 (1-2) ◽  
pp. 265-279 ◽  
Author(s):  
Tomasz Błeński ◽  
Jacques Ligou
Keyword(s):  
Cross Sections ◽  
Temperature Dependent ◽  
Absorption Bands ◽  
Thomas Fermi ◽  
Model Based ◽  
Atom Model ◽  
Independent Particle ◽  
Average Atom Model

We present some results of our opacity calculations for lead and gold at temperatures and densities relevant to ICF conditions. We use an average atom model based on the temperature dependent Thomas-Fermi shell approach. The absorption bands (broadening of lines) are accounted for with a simple T.F. fluctuation formula. The independent particle bound-bound, bound-free, and free-free photon cross-sections are taken without further approximations.

DISCOVERED FUNCTION FOR POSITRON COLLISIONS WITH ALKALI-METAL ATOMS USING GENETIC PROGRAMMING

2007 ◽  
Vol 18 (03) ◽  
pp. 351-358 ◽  
Author(s):  
SALAH YASEEN EL-BAKRY ◽  
AMR RADI
Keyword(s):  
Experimental Data ◽  
Genetic Programming ◽  
Cross Sections ◽  
Target Atom ◽  
Dipole Polarizability ◽  
Sodium Potassium ◽  
Intermediate Energies ◽  
Alkali Atoms ◽  
Input Variables ◽  
Positron Collisions

Genetic programming (GP) has been used to discover the function that describes the collisions of positrons with sodium, potassium, rubidium and cesium atoms at low and intermediate energies. The GP has been running based on experimental data of the total collisional cross sections to produce the total cross sections for each target atom. The incident energy and the static dipole polarizability of the alkali target atom have been used as input variables to find the discovered function. The experimental, calculated and predicted total collisional cross sections are compared. The discovered function shows a good match to the experimental data. We find that the GP technique is able to improve upon more traditional methods. To our knowledge, this is the first application of the GP technique to the data of positron collisions with alkali atoms at low and intermediate energies.

Experimental study on electron detachment cross sections of Cl– in collisions with inert gas atoms

2020 ◽  
Vol 98 (3) ◽  
pp. 287-290
Author(s):  
Mingmin Luo ◽  
Yujia Zhai ◽  
Guannan Guo ◽  
Xuemei Zhang
Keyword(s):  
Experimental Study ◽  
Growth Rate ◽  
Cross Sections ◽  
Negative Ions ◽  
Target Atom ◽  
Single Electron ◽  
Inert Gas ◽  
Electron Detachment ◽  
Double Electron ◽  
Rate Method

The single-electron and double-electron detachment cross sections of Cl– in collision with inert gas atoms (He–Xe) have been measured by the growth rate method. The incident negative ions’ energies are from 5 to 30 keV. It is found that the single-electron detachment cross sections become greater and greater when the target atoms change from helium to xenon. However, double-electron detachment cross sections show a more complicated relationship with the target atom changing. The results of this work have been compared with the previous data, and a model based on energy division is used to interpret the trends of cross sections.

Proton and antiproton impact excitation of H(2s) atom

2015 ◽  
Vol 93 (11) ◽  
pp. 1360-1364 ◽  
Author(s):  
Reda S. Tantawi ◽  
A. Nagah
Keyword(s):  
Impact Parameter ◽  
Cross Sections ◽  
Atomic Orbital ◽  
Target Atom ◽  
Impact Excitation ◽  
Final States ◽  
Close Coupling ◽  
Coupling Approach ◽  
The One ◽  
The Impact

Direct excitations for atomic hydrogen 2s → 3s, 3p, and 3d transitions by proton and antiproton collisions have been investigated by using an impact parameter treatment. The calculations are performed within the impact parameter versions of the first- and second-order Born approximations, as well as the solution of the coupled differential equations arising from the one-center atomic-orbital close-coupling approach. We have considered calculations that allow couplings to the n = 1–5 states (up to g sub-levels) of the target atom as well as others that neglect the effect of all states other than the initial and final states of the target atom. The sensitivity of the cross sections to the sign of the projectile charge as well as the influence of the mechanism of possible electronic transitions allowed by the techniques under consideration have been studied. The calculated cross sections are compared with those obtained by previous calculations.

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