Ionization by protons in the energy range 100 to 450 keV

1963 ◽  
Vol 274 (1358) ◽  
pp. 365-370 ◽  
Keyword(s):  
Energy Range ◽  
Cross Section ◽  
Cross Sections ◽  
Ionization Cross Section ◽  
Axial Magnetic Field ◽  
High Energy ◽  
Ionization Cross ◽  
Total Ionization ◽  
Ion Production ◽  
Ionization Cross Sections

Ionization by protons in the energy range 100 to 450 keV has been investigated by means of the well-known parallel-plate condenser method. A uniform axial magnetic field enables slow ion collection to be carried out over a precisely determined path length at pressures low enough to ensure single collision conditions. The total cross-section for slow ion production cr+, and the total ionization cross-section have been determined for protons in hydrogen, helium , neon, argon and krypton. It is found that charge transfer is very small above about 200 keV so that cr+ ~ cr e . The ionization cross-section for all cases falls off as E -1 log E where E is the energy of relative motion. At the high-energy limit of the present measurements, the proton ionization cross-sections agree closely with electron ionization cross-sections for the same relative velocity of impact. The results are therefore in agreement with the general predictions of the Born approximation.

scholarly journals Direct and Dissociative Ionization Cross Section of Oxygen Molecule from Threshold to 10 KeV

2019 ◽  
Vol 8 (6S3) ◽  
pp. 1365-1368
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Ionization Cross Section ◽  
Threshold Energy ◽  
Theoretical Data ◽  
Oxygen Molecule ◽  
Dissociative Ionization ◽  
Ionization Cross ◽  
Section Data ◽  
Ionization Cross Sections

Due to abundant applications of ionization in various fields of applied sciences, it’s desirable to calculate absolute ionization cross sections of various atoms or molecules. In this literature, we have calculated the absolute direct and dissociative ionization cross sections of the oxygen molecule from threshold energy to 10,000 eV by using revisited Jain-Khare semi-empirical approach. In this literature, the total direct and absolute ionization cross section data have compared with easily available experimental and/or theoretical data. The present results give a better account for the ionization cross sections up to higher incident electron energies.

Ionization Cross Sections for Quantitative Electron Probe Microanalysis

2001 ◽  
Vol 7 (S2) ◽  
pp. 672-673
Author(s):  
C. Merlet ◽  
X. Llovet ◽  
S. Segui ◽  
J.M. Fernández-Varea ◽  
F. Salvat
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Ionization Cross Section ◽  
Ionization Cross ◽  
Quantitative Electron Probe Microanalysis ◽  
Ionization Cross Sections ◽  
Semi Empirical ◽  
Quantitative Epma

Quantitative procedures in electron probe microanalysis (EPMA) require the knowledge of various atomic parameters, the most fundamental of which is the ionization cross section. A number of semi-empirical, approximate analytical formulas have been proposed to calculate the ionization cross section. The simplicity of these formulas makes them suitable for quantitative EPMA procedures. However, it is difficult to assess their reliability because of the lack of accurate experimental data. Indeed, inspection of currently available data reveals that they are still scarce for many elements and, when they are available, one usually finds significant discrepancies between data from different authors. Fortunately, the inaccuracies in the semi-empirical cross section formulas used in EPMA have only a small effect on the analytical results when standards are used. Nonetheless, in quantitative EPMA studies at low overvoltages or using standardless methods, the evaluated compositions largely depend on the adopted ionization cross sections and, therefore, knowledge of accurate ionization cross sections is a requisite for the development of improved quantification methods.

Ionization in collisions between 30–1000 keV antiprotons and atomic hydrogen

1996 ◽  
Vol 74 (7-8) ◽  
pp. 490-495 ◽  
Author(s):  
K. Paludan ◽  
H. Knudsen ◽  
U. Mikkelsen ◽  
M. Charlton ◽  
K. Kirsebom ◽  
...  
Keyword(s):  
Energy Range ◽  
Cross Section ◽  
Cross Sections ◽  
Atomic Hydrogen ◽  
Theoretical Calculations ◽  
Published Data ◽  
Ionization Cross ◽  
Ionization Cross Sections ◽  
Impact Energies ◽  
Theoretical Results

Recently published data for impact of antiprotons in the energy range 30–1000 keV on atomic hydrogen are compared with analogous proton, electron, and positron measurements, and it is found that the ionization cross sections of atomic hydrogen follow the same pattern as similar cross sections obtained on He and H2 targets, in accordance with the general phenomenological description of single ionization that has developed over the last decade. Further comparisons are made with various recent and advanced theoretical calculations for antiproton ionization of atomic hydrogen. These theoretical results agree well with the data obtained, but for lower impact energies the different methods do not, despite the simplicity of the system, agree on predicting even the form of the cross section.

Electron impact ionization cross sections of hydrogen fluoride molecule

2019 ◽  
Vol 26 (3) ◽  
pp. 195-203
Author(s):  
Rajeev Kumar ◽  
SP Sharma ◽  
Ravinder Sharma
Keyword(s):  
Hydrogen Fluoride ◽  
Cross Sections ◽  
Impact Ionization ◽  
Theoretical Data ◽  
High Energy ◽  
Primary Electron ◽  
Ionization Cross ◽  
Total Ionization ◽  
Semiempirical Approach ◽  
Ionization Cross Sections

Partial and total ionization cross sections of hydrogen fluoride molecule are determined from the ionization threshold to high energy (5 KeV) by using a modified Jain–Khare semiempirical approach. Partial single and double differential cross sections with their sums (total) through direct and dissociative ionization have been also evaluated at fixed primary electron energies 100 eV, 200 eV, and 500 eV. There is no other data for partial ionization cross sections and differential ionization cross sections for comparison. In this paper, the total ionization cross sections data have compared with available experimental data and/or with other theoretical data which are available from intermediate to high energy. It is found that the present result gives a better account for the ionization cross sections up to higher energies.

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