Binary encounter calculations on electron impact double ionization of noble gas atoms

Electron impact double ionization cross sections of noble gas atoms have been calculated in the binary encounter approximation by using Gryzinski's double binary encounter model. The correct expression for σΔE including exchange and interference as given by Vriens has been used. Hartree–Fock and hydrogenic velocity distribution functions have been used in considering the ejection of the first and the second atomic electron, respectively. Contribution of ionization from inner-shell has also been taken into account. Calculated values of cross sections are found to be in agreement with the experimental observations.

Download Full-text

Electron Impact Double Ionization of Noble Gas Atoms

Canadian Journal of Physics ◽

10.1139/p72-390 ◽

1972 ◽

Vol 50 (23) ◽

pp. 2961-2966 ◽

Cited By ~ 9

Author(s):

B. N. Roy ◽

D. N. Tripathi ◽

D. K. Rai

Keyword(s):

Electron Impact ◽

Cross Sections ◽

Noble Gas ◽

Double Ionization ◽

Experimental Results ◽

Ionization Cross ◽

Proton Impact ◽

Classical Expression ◽

Ionization Cross Sections

Cross sections for double ionization by electron impact for noble gas atoms have been calculated using Gryzinski's classical expression. The effect of including ionization from the inner shell has been discussed in connection with possible Auger emission. Calculated cross sections have been compared with the available experimental results and also with calculated values of proton impact double ionization cross sections.

Download Full-text

Electron-impact double ionization of the carbon atom

Astronomy and Astrophysics ◽

10.1051/0004-6361/201834303 ◽

2018 ◽

Vol 620 ◽

pp. A188 ◽

Cited By ~ 6

Author(s):

Valdas Jonauskas

Keyword(s):

Carbon Atom ◽

Electron Impact ◽

Cross Sections ◽

Double Ionization ◽

Impact Excitation ◽

Rate Coefficients ◽

Electron Impact Excitation ◽

Ionization Cross ◽

Ionization Cross Sections ◽

Good Agreement

Electron-impact single- and double-ionization cross sections and Maxwellian rate coefficients are presented for the carbon atom. Scaling factors are introduced for the electron-impact excitation and ionization cross sections obtained in the distorted wave (DW) approximation. It is shown that the scaled DW cross sections provide good agreement with measurements for the single ionization of the C atom and C1+ ion. The direct double-ionization (DDI) process is studied using a multi-step approach. Ionization–ionization, excitation–ionization–ionization, and ionization–excitation–ionization branches are analyzed. It is demonstrated that the three-step processes contribute ≼40% of the total DDI cross sections for the case where one of the electrons takes all of the excess energy after the first ionization process.

Download Full-text

Electron impact total and ionization cross sections for Sr, Y, Ru, Pd, and Ag atoms

Canadian Journal of Physics ◽

10.1139/cjp-2013-0174 ◽

2013 ◽

Vol 91 (9) ◽

pp. 744-750 ◽

Cited By ~ 7

Author(s):

Dhanoj Gupta ◽

Rahla Naghma ◽

Bobby Antony

Keyword(s):

Electron Impact ◽

Cross Sections ◽

Optical Potential ◽

Atomic Orbital ◽

Atomic Charge ◽

Ionization Cross ◽

Charge Densities ◽

Hartree Fock ◽

Spherical Complex ◽

Ionization Cross Sections

Calculation of electron impact total and ionization cross sections for Sr, Y, Ru, Pd, and Ag atoms were performed using spherical complex optical potential and complex scattering potential-ionization contribution methods. The complex optical potential model is formulated from the target parameters and the atomic charge density. The spherical charge densities are in turn derived from the Roothaan–Hartree–Fock wavefunctions defining the atomic orbital of the target. In the present study cross sections are computed in the energy range from ionization threshold to 2000 eV. The results obtained are compared with other theories and measurements wherever available and were found to be quite consistent and uniform. In general, present data show an overall reasonable agreement with other results. Dependence of total cross sections on the number of target electrons and peak of ionization cross section on target parameters were also found to be consistent with previous observations.

Download Full-text