Electron capture by multicharged ions from hydrogen atoms at eV energies (original) (raw)
Related papers
Electron capture from atomic hydrogen by multiply charged ions in low energy collisions
Journal de Physique, 1985
2014 On a mesuré et calculé les sections efficaces de capture dans l'hydrogène atomique par des ions multichargés. Les expériences ont été faites avec les ions Nq+, Oq+ et Neq+ comme projectiles dans la gamme d'énergie 2 q à 10 q keV. On obtient en général un bon accord avec les mesures antérieures quand celles-ci sont disponibles. Les calculs utilisent la méthode moléculaire, avec facteurs de translation. Ils concernent les projectiles complètement épluchés avec une charge comprise entre 5 et 10 ainsi que O6+(1s2) et N5+(1s2). Le rôle de l'interaction c0153ur-électron actif est discuté. On obtient un bon accord entre la théorie et l'expérience. Tant les résultats expérimentaux que les résultats théoriques sont exempts d'oscillations en fonction de la charge du projectile dans le domaine d'énergie couvert par les expériences. Abstract 2014 Cross section measurements and calculations are presented for electron capture by multiply charged ions from atomic hydrogen. The measurements were made for Nq+, Oq+ and Neq+ projectiles in the energy range 2 q to 10 q keV. Fair agreement is obtained with most earlier measurements when available. Molecular calculations, including translation factors, have been carried out for the case of fully stripped projectiles with charges between 5 and 10 as well as for O6+(1s2) and N5+(1s2) impact The role of the interaction between the core and active electron is discussed Good agreement is obtained between theory and experiment. It is worth noting that both experimental and theoretical results do not show any oscillation as a function of the projectile charge in the energy range covered by the experiments.
ELECTRON CAPTURE BY MULTICHARGED IONS AT eV ENERGIES
Le Journal de Physique Colloques
A multicharged ion-atom merged-beams apparatus has been used i n conjunction w i t h the ORNL-ECR i o n sour.ce t o measure accurate absolute e l ectron-capture cross sections i n t h e energy range from below 1 eVlamu t o 1500 eVlamu. Measurements f o r N3+.4+~5+ + H(D) c o l l i s i o n s i n d i c a t e good agreement w i t h a v a i l a b l e t h e o r e t i c a l calculat i o n s . However, measurements w i t h 05+ + H(D) show an unexpected low-energy behavior which may be a t t r i b u t a b l e t o the ion-induced-dipole a t t r a c t i o n between the reactants. Scaled Landau-Zener c a l c u l a t i o n s presented here i d e n t i f y a t r a n s f e r p l u s e x c i t a t i o n channel which has the c o r r e c t energy dependence a t low energies. This f i n d i n g suggests the need f o r a comprehensive Coupled channel c a l c u l a t i o n which would include such product states.
Single-electron capture by highly charged ions colliding with atomic and molecular hydrogen
Physical Review A, 1981
The ratio between the cross sections for single-electron capture by highly charged ions colliding with atomic and molecular hydrogen has been investigated within the framework of the Bohr-Lindhard theory. It is shown that cr(H2)/a (H) can be represented as a universal function of the inherent scaling parameter over a wide range of ion energy and charge states. Generally, the ratio is different from the often-assumed value of 2.
Single-electron-capture cross sections of multiply-charged ions colliding with H, H2 and He
Radiation Center of Osaka Prefecture Technical Report, 1987
A universal semiempirical formula is given for the total cross sections 𝜎_(q,q-1)^B of single-electron-capture processes: A^(q+)+B→A^{(q-1)+}+B^+, where A stands for the projectile of almost all atoms, and B the target of H, H_2 or He. Values of constants in this formula have been determined by the least-squares fit to a total of 1316 experimental data points collected from references. The formula applies to q≧4 for the targets of H and H_2 and to q≧5 for He in the energy region of projectiles from about 1 to 10^7 eV/amu. The root-mean-square deviation of the data points from the formula is 29%. In the low-energy region, the formula indicates that 𝜎_(q,q-1)^B is proportional to q^(1.01). The curves given by the formula are plotted in graphs together with the data. [Note: We finally published this work here: Yohta Nakai, Toshizo Shirai, Tatsuo Tabata, and Rinsuke Ito, "A semiempirical formula for single-electron-capture cross sections of multiply charged Ions colliding with H, H2 and He." Physica Scripta Vol. T28, 77-80 (1989).]
Ionization and charge transfer in high-energy ion-atom collisions
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1987
Electron capture and loss by fast highly charged ions in a gas target, and ionization of the target by passage of the fast projectile beam, are fundamental processes in atomic physics. These processes, along with excitation, can be experimentally studied separately (''singles'') or together (''coincidence''). This paper is a review of recent results on singles measurements for electron capture and
1978
Cross sections for electron capture by N+', 0+' (1 & q & 5), .and C+' (1 & q & 4) incident on atomic and molecular hydrogen have been measured in the velocity range (0.3-5.2) )& 10' cm/s. The capture cross sections for the higher incident charge states ar'e large, in many cases exceeding 1 X 10 " cm'. For relative velocities above the Boh'r velocity, all the measured cross sections were found to decrease monotonically with increasing velocity and to scale in magnitude roughly as q . Furthermore, for these higher velocities the cross sections for electron capture from H, are systematically larger than the corresponding cross sections for electron capture from H. For relative velocities below the Bohr velocity, no simple behavior of the measured cross sections was observed. The behavior of the cross sections at 1'ow velocities is discussed qualitatively using the Landau-Zener formalism. For higher velocities reasonable agreement was found with the classical trajectory Monte Carlo calculations of Olson and Salop.
Correlation effects on double electron capture in highly-charged, low-energy ion-atom collisions
1987
The method of zero-degree Auger electron spectroscopy has been used to study two-electron excited states populated in slow double capture collisions of highly charged ions with He and H sub 2. The focus of this study is on production of autoionization electrons originating from the non-equivalent 1s (2) 2 pnl electron configurations in comparison with electron production resulting from the
Multiple-electron capture and ionization in heavy-ion-atom collisions
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1987
Multiple-vacancy production in the rare gas atoms He, Ne, Ar, Kr and Xe by 1.4 MeV/u highly stripped ion impact is studied. From a recoil-ion-projectile-ion coincidence experiment charge-state distributions of target ions were obtained distinguishing between pure ionization and capture of up to three electrons by projectile ions N6+17', Fe12+~151~20+~21+, Krr8+, Gd3'+, and U30+,36+,41 +q44-c,4s+. For high-charge-state projectiles the relative fractions of recoil ions for concomitant electron capture and ionization are found to be independent of projectile charge or species.