Abstract
A model, based on the adiabatic perturbation theory, is proposed to the ionization of the 1s{sigma} molecular orbital in slow asymmetric collisions. The extension of the model to less adiabatic collisions is made by imposing an asymptotic matching with the semiclassical approximation. The transient molecular state wavefunction is evaluated using an effective charge, which is dependent on the internuclear separation distance, for the projectile-target-atom-system. This procedure simulates both the screening due to the external electrons and the modifications on the electronic wavefunction due to the nuclei relative motion. The direct Coulomb ionization cross-section of the 1s{sigma} molecular orbital is calculated for projectiles following hyperbolic paths in terms of this effective charge. At the same time, X-rays production cross-sections for the K-shell of thick targets of Ti and Fe are determined for incident beams of D, He, C, N and O, with energy range between 0,20 and 4,00 MeV. The comparison between the proposed model and the obtained experimental data shows that, for this energy range, two other processes, besides direct ionization, contribute to X-rays production. These processes, namely the recoil of the target-atom in its matrix and the electron capture by the projectile, are discussed in the light of theoretical
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Citation Formats
Sigaud, G M.
Study on the ionization of 1s{sigma} molecular orbital in slow asymmetric collisions; Estudo da ionizacao do orbital molecular 1s{sigma} em colisoes assimetricas lentas.
Brazil: N. p.,
1985.
Web.
Sigaud, G M.
Study on the ionization of 1s{sigma} molecular orbital in slow asymmetric collisions; Estudo da ionizacao do orbital molecular 1s{sigma} em colisoes assimetricas lentas.
Brazil.
Sigaud, G M.
1985.
"Study on the ionization of 1s{sigma} molecular orbital in slow asymmetric collisions; Estudo da ionizacao do orbital molecular 1s{sigma} em colisoes assimetricas lentas."
Brazil.
@misc{etde_10102399,
title = {Study on the ionization of 1s{sigma} molecular orbital in slow asymmetric collisions; Estudo da ionizacao do orbital molecular 1s{sigma} em colisoes assimetricas lentas}
author = {Sigaud, G M}
abstractNote = {A model, based on the adiabatic perturbation theory, is proposed to the ionization of the 1s{sigma} molecular orbital in slow asymmetric collisions. The extension of the model to less adiabatic collisions is made by imposing an asymptotic matching with the semiclassical approximation. The transient molecular state wavefunction is evaluated using an effective charge, which is dependent on the internuclear separation distance, for the projectile-target-atom-system. This procedure simulates both the screening due to the external electrons and the modifications on the electronic wavefunction due to the nuclei relative motion. The direct Coulomb ionization cross-section of the 1s{sigma} molecular orbital is calculated for projectiles following hyperbolic paths in terms of this effective charge. At the same time, X-rays production cross-sections for the K-shell of thick targets of Ti and Fe are determined for incident beams of D, He, C, N and O, with energy range between 0,20 and 4,00 MeV. The comparison between the proposed model and the obtained experimental data shows that, for this energy range, two other processes, besides direct ionization, contribute to X-rays production. These processes, namely the recoil of the target-atom in its matrix and the electron capture by the projectile, are discussed in the light of theoretical models existent in the literature. (author).}
place = {Brazil}
year = {1985}
month = {Dec}
}
title = {Study on the ionization of 1s{sigma} molecular orbital in slow asymmetric collisions; Estudo da ionizacao do orbital molecular 1s{sigma} em colisoes assimetricas lentas}
author = {Sigaud, G M}
abstractNote = {A model, based on the adiabatic perturbation theory, is proposed to the ionization of the 1s{sigma} molecular orbital in slow asymmetric collisions. The extension of the model to less adiabatic collisions is made by imposing an asymptotic matching with the semiclassical approximation. The transient molecular state wavefunction is evaluated using an effective charge, which is dependent on the internuclear separation distance, for the projectile-target-atom-system. This procedure simulates both the screening due to the external electrons and the modifications on the electronic wavefunction due to the nuclei relative motion. The direct Coulomb ionization cross-section of the 1s{sigma} molecular orbital is calculated for projectiles following hyperbolic paths in terms of this effective charge. At the same time, X-rays production cross-sections for the K-shell of thick targets of Ti and Fe are determined for incident beams of D, He, C, N and O, with energy range between 0,20 and 4,00 MeV. The comparison between the proposed model and the obtained experimental data shows that, for this energy range, two other processes, besides direct ionization, contribute to X-rays production. These processes, namely the recoil of the target-atom in its matrix and the electron capture by the projectile, are discussed in the light of theoretical models existent in the literature. (author).}
place = {Brazil}
year = {1985}
month = {Dec}
}