Using the dynamical variational method fully differential cross sections have been calculated for... more Using the dynamical variational method fully differential cross sections have been calculated for electron-impact ionization of the hydrogen atom. The study shows that inclusion of the effective charge seen by the scattered electron into the calculation noticeably improves agreement between theory and experiment, especially in the region of a "binary peak".
Journal of Physics B Atomic Molecular and Optical Physics
We present a theoretical study of electron-impact single ionization of [iopmath latex="$\rm ... more We present a theoretical study of electron-impact single ionization of [iopmath latex="$\rm Ne^{7 + }(1s^2 2s ~ {}^2S)$"] Ne7+(1s22s 2S) [/iopmath] using a formulation in which the incident/scattered electron is described by distorted waves, while the final continuum states of [iopmath latex="$\rm Ne^{7 + }$"] Ne7+ [/iopmath] are calculated by the R-matrix method, thereby incorporating the excitation-autoionization process. With nine states of the residual [iopmath latex="$\rm Ne^{8 + }$"] Ne8+ [/iopmath] included, we have calculated single-differential and total cross sections for impact energies from the threshold energy at 8.8-80 au. The single-differential cross sections exhibit considerable structure due to autoionizing resonances, dominated by the [iopmath latex="$\rm1s 2\ell 2\ell'$"] 1s22' [/iopmath] states. Our calculated total cross section is in good agreement with the available experimental data and with theoretical values ...
Journal of Physics B: Atomic, Molecular and Optical Physics, 2010
Page 1. Electron impact multiple ionization of argon ions This article has been downloaded from I... more Page 1. Electron impact multiple ionization of argon ions This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2010 J. Phys. B: At. Mol. Opt. Phys. 43 185203 (http://iopscience.iop.org/0953-4075/43/18/185203) ...
Journal of Physics B: Atomic, Molecular and Optical Physics, 2001
ABSTRACT We present a theoretical study of electron-impact single ionization of Ne7+(1s22s 2S) us... more ABSTRACT We present a theoretical study of electron-impact single ionization of Ne7+(1s22s 2S) using a formulation in which the incident/scattered electron is described by distorted waves, while the final continuum states of Ne7+ are calculated by the R-matrix method, thereby incorporating the excitation-autoionization process. With nine states of the residual Ne8+ included, we have calculated single-differential and total cross sections for impact energies from the threshold energy at 8.8-80 au. The single-differential cross sections exhibit considerable structure due to autoionizing resonances, dominated by the 1s2ℓ2ℓ' states. Our calculated total cross section is in good agreement with the available experimental data and with theoretical values obtained by a close-coupling calculation. Total cross sections for ionization in which the Ne8+ is left in the 1s2s 1,3S or 1s2p 1,3Po excited states are also presented.
ABSTRACT Characteristics of Rydberg states for diatomic molecules H2, HeH+, C2+,N2+ are calculate... more ABSTRACT Characteristics of Rydberg states for diatomic molecules H2, HeH+, C2+,N2+ are calculated in the basis of Coulomb spheroidal wave functions. The results are compared to the more sophisticated calculations and efficiency of the Coulomb spheroidal basis for molecular calculations is examined
For the first time total cross sections for double ionization of two-electron atomic systems He, ... more For the first time total cross sections for double ionization of two-electron atomic systems He, Li + , Be 2+ , B 3+ and C 4+ being in the 2 1 S and 2 3 S metastable states are calculated within the framework of the shake-off model. Only radial correlation between the target electrons is taken into account and repulsion between the ejected electrons is ignored.
Absolute cross sections and kinetic energy release distributions for electron impact ionization a... more Absolute cross sections and kinetic energy release distributions for electron impact ionization and dissociation of CD+
Abstract. Absolute cross sections for electron impact dissociation of ND + leading to the formati... more Abstract. Absolute cross sections for electron impact dissociation of ND + leading to the formation of D + have been measured by applying the animated electron-ion beam method in the energy range from the reaction threshold up to 2.5 keV. The maximum inclusive cross section is observed to be (16.8 ± 0.8) × 10 −17 cm 2 at the electron energy of 65.1 eV. The appearance energy for the D + production is measured to be (4.0 ± 0.5) eV. Collected data are analyzed in details by means of an original procedure in order to determine separately the contributions of dissociative channels. A specific Monte Carlo modeling has been developed, which is proven to reconstruct adequately the dissociative ionization cross section. The present energy thresholds provide information about the ground and excited states of the molecular ion, as well as about the possible population of the vibrational levels. The reaction D2(v)+N + (or H2(v)+N +)isa probable source for that population and it constitutes the ...
The dissociative recombination of the methane-derived group, CH+, . . . , CH:, has been measured ... more The dissociative recombination of the methane-derived group, CH+, . . . , CH:, has been measured over the centre-of-mass energy interval 0.03 to 2 eV. Assuming a Maxwellian distribution of the electron velocities, the derived rate coefficients for CH+, . . . , CH; at 100 K are, respectively, 5, 8.7, 12, 12.8 and 12.8 x lo-' cm3 s-', The recombination cross section for the diatomic ion CHC is large. This has far reaching consequences for the theories of molecular formation in interstellar clouds. The cross sections for the polyatomics CH;, . . . , CH: are also large and roughly equal in magnitude. Like CH' they exhibit a close to E-' energy dependence below 0.1 eV. For CH:, CHf and CH; the slope of the cross sections increases above 0.1 eV.
Journal of Physics B: Atomic, Molecular and Optical Physics, 2001
First absolute cross sections for electron impact single ionization of H3O+, HD2O+ and D3O+ and f... more First absolute cross sections for electron impact single ionization of H3O+, HD2O+ and D3O+ and for dissociative excitation (DE) producing H+ and D+ are reported. The animated crossed electron-ion beam method has been employed in the energy range from threshold to 2500 eV. The maxima of these cross sections are found to be unusually small (<1×10-17 cm2). The ionization threshold
Abstract. Dissociative excitation of N2H+ has been investigated in the energy range from 7.5 to 2... more Abstract. Dissociative excitation of N2H+ has been investigated in the energy range from 7.5 to 2500 eV using a crossed beams apparatus. Absolute cross sections are reported for the channel leading to NH+ formation. Good agreement is found with the previous results of Fogle et al, from the Oak Ridge group [1]. The threshold measured for this channel indicates the presence of excited states in the target beam. 1.
Using the dynamical variational method fully differential cross sections have been calculated for... more Using the dynamical variational method fully differential cross sections have been calculated for electron-impact ionization of the hydrogen atom. The study shows that inclusion of the effective charge seen by the scattered electron into the calculation noticeably improves agreement between theory and experiment, especially in the region of a "binary peak".
Journal of Physics B Atomic Molecular and Optical Physics
We present a theoretical study of electron-impact single ionization of [iopmath latex="$\rm ... more We present a theoretical study of electron-impact single ionization of [iopmath latex="$\rm Ne^{7 + }(1s^2 2s ~ {}^2S)$"] Ne7+(1s22s 2S) [/iopmath] using a formulation in which the incident/scattered electron is described by distorted waves, while the final continuum states of [iopmath latex="$\rm Ne^{7 + }$"] Ne7+ [/iopmath] are calculated by the R-matrix method, thereby incorporating the excitation-autoionization process. With nine states of the residual [iopmath latex="$\rm Ne^{8 + }$"] Ne8+ [/iopmath] included, we have calculated single-differential and total cross sections for impact energies from the threshold energy at 8.8-80 au. The single-differential cross sections exhibit considerable structure due to autoionizing resonances, dominated by the [iopmath latex="$\rm1s 2\ell 2\ell'$"] 1s22' [/iopmath] states. Our calculated total cross section is in good agreement with the available experimental data and with theoretical values ...
Journal of Physics B: Atomic, Molecular and Optical Physics, 2010
Page 1. Electron impact multiple ionization of argon ions This article has been downloaded from I... more Page 1. Electron impact multiple ionization of argon ions This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2010 J. Phys. B: At. Mol. Opt. Phys. 43 185203 (http://iopscience.iop.org/0953-4075/43/18/185203) ...
Journal of Physics B: Atomic, Molecular and Optical Physics, 2001
ABSTRACT We present a theoretical study of electron-impact single ionization of Ne7+(1s22s 2S) us... more ABSTRACT We present a theoretical study of electron-impact single ionization of Ne7+(1s22s 2S) using a formulation in which the incident/scattered electron is described by distorted waves, while the final continuum states of Ne7+ are calculated by the R-matrix method, thereby incorporating the excitation-autoionization process. With nine states of the residual Ne8+ included, we have calculated single-differential and total cross sections for impact energies from the threshold energy at 8.8-80 au. The single-differential cross sections exhibit considerable structure due to autoionizing resonances, dominated by the 1s2ℓ2ℓ' states. Our calculated total cross section is in good agreement with the available experimental data and with theoretical values obtained by a close-coupling calculation. Total cross sections for ionization in which the Ne8+ is left in the 1s2s 1,3S or 1s2p 1,3Po excited states are also presented.
ABSTRACT Characteristics of Rydberg states for diatomic molecules H2, HeH+, C2+,N2+ are calculate... more ABSTRACT Characteristics of Rydberg states for diatomic molecules H2, HeH+, C2+,N2+ are calculated in the basis of Coulomb spheroidal wave functions. The results are compared to the more sophisticated calculations and efficiency of the Coulomb spheroidal basis for molecular calculations is examined
For the first time total cross sections for double ionization of two-electron atomic systems He, ... more For the first time total cross sections for double ionization of two-electron atomic systems He, Li + , Be 2+ , B 3+ and C 4+ being in the 2 1 S and 2 3 S metastable states are calculated within the framework of the shake-off model. Only radial correlation between the target electrons is taken into account and repulsion between the ejected electrons is ignored.
Absolute cross sections and kinetic energy release distributions for electron impact ionization a... more Absolute cross sections and kinetic energy release distributions for electron impact ionization and dissociation of CD+
Abstract. Absolute cross sections for electron impact dissociation of ND + leading to the formati... more Abstract. Absolute cross sections for electron impact dissociation of ND + leading to the formation of D + have been measured by applying the animated electron-ion beam method in the energy range from the reaction threshold up to 2.5 keV. The maximum inclusive cross section is observed to be (16.8 ± 0.8) × 10 −17 cm 2 at the electron energy of 65.1 eV. The appearance energy for the D + production is measured to be (4.0 ± 0.5) eV. Collected data are analyzed in details by means of an original procedure in order to determine separately the contributions of dissociative channels. A specific Monte Carlo modeling has been developed, which is proven to reconstruct adequately the dissociative ionization cross section. The present energy thresholds provide information about the ground and excited states of the molecular ion, as well as about the possible population of the vibrational levels. The reaction D2(v)+N + (or H2(v)+N +)isa probable source for that population and it constitutes the ...
The dissociative recombination of the methane-derived group, CH+, . . . , CH:, has been measured ... more The dissociative recombination of the methane-derived group, CH+, . . . , CH:, has been measured over the centre-of-mass energy interval 0.03 to 2 eV. Assuming a Maxwellian distribution of the electron velocities, the derived rate coefficients for CH+, . . . , CH; at 100 K are, respectively, 5, 8.7, 12, 12.8 and 12.8 x lo-' cm3 s-', The recombination cross section for the diatomic ion CHC is large. This has far reaching consequences for the theories of molecular formation in interstellar clouds. The cross sections for the polyatomics CH;, . . . , CH: are also large and roughly equal in magnitude. Like CH' they exhibit a close to E-' energy dependence below 0.1 eV. For CH:, CHf and CH; the slope of the cross sections increases above 0.1 eV.
Journal of Physics B: Atomic, Molecular and Optical Physics, 2001
First absolute cross sections for electron impact single ionization of H3O+, HD2O+ and D3O+ and f... more First absolute cross sections for electron impact single ionization of H3O+, HD2O+ and D3O+ and for dissociative excitation (DE) producing H+ and D+ are reported. The animated crossed electron-ion beam method has been employed in the energy range from threshold to 2500 eV. The maxima of these cross sections are found to be unusually small (<1×10-17 cm2). The ionization threshold
Abstract. Dissociative excitation of N2H+ has been investigated in the energy range from 7.5 to 2... more Abstract. Dissociative excitation of N2H+ has been investigated in the energy range from 7.5 to 2500 eV using a crossed beams apparatus. Absolute cross sections are reported for the channel leading to NH+ formation. Good agreement is found with the previous results of Fogle et al, from the Oak Ridge group [1]. The threshold measured for this channel indicates the presence of excited states in the target beam. 1.
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