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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Charge State Dependence of M-Shell X-Ray Production in 67Ho by 2-12 MeV Carbon Ions

Sun, Hsueh-Li 08 1900 (has links)
The charge state dependence of M-shell x-ray production cross sections of 67HO bombarded by 2-12 MeV carbon ions with and without K-vacancies are reported. The experiment was performed using an NEC 9SDH-2 tandem accelerator at the Ion Beam Modification and Analysis Laboratory of the University of North Texas. The high charge state carbon ions were produced by a post-accelerator stripping gas cell. Ultra-clean holmium targets were used in ion-atom collision to generate M-shell x rays at energies from 1.05 to 1.58 keV. The x-ray measurements were made with a windowless Si(Li) x-ray detector that was calibrated using radiative sources, particle induced x-ray emission (PIXE), and the atomic field bremsstrahlung (AFB) techniques.
12

Electron-transfer processes in fast ion-atom collisions

Støchkel, Kristian January 2005 (has links)
<p>The subject of this thesis is experimental studies of electron-transfer processes in ion-atom collisions at velocities significantly higher than typical orbital velocities of electrons in bound states of atoms or molecules. The experimental technique applied combines the high beam intensity of heavy-ion storage rings with a supersonic gas-jet target equipped with a recoil-ion-momentum spectrometer. In singleelectron capture to fast protons from helium atoms, we have for the first time achieved a complete separation of the kinematic and Thomas transfer mechanisms and are able to perform a quantitative comparison with the many theoretical results on a much more detailed level than what was previously possible. For the process of transfer ionization in proton-helium collisions we have determined the velocity dependence of the Thomas transfer ionization cross section to be the expected<i> v</i><i>p</i><sup>-11</sup> when the projectile velocity, <i>v</i><i>p</i>, is sufficiently high. Further, we have determined the velocity-dependent probability for shake-off of the second electron from helium provided that the first one is transferred in a kinematic capture process. Finally, we have considered collisions between protons and hydrogen molecules. Here we have found a strong variation in the cross section for transfer and excitation processes when the angle between the direction of the incoming projectile and the internuclear axis of the target molecule is varied. The variation can be explained as a result of quantum mechanical interference related to the two indistinguishable atomic centers of the molecule.</p>
13

Electron-transfer processes in fast ion-atom collisions

Støchkel, Kristian January 2005 (has links)
The subject of this thesis is experimental studies of electron-transfer processes in ion-atom collisions at velocities significantly higher than typical orbital velocities of electrons in bound states of atoms or molecules. The experimental technique applied combines the high beam intensity of heavy-ion storage rings with a supersonic gas-jet target equipped with a recoil-ion-momentum spectrometer. In singleelectron capture to fast protons from helium atoms, we have for the first time achieved a complete separation of the kinematic and Thomas transfer mechanisms and are able to perform a quantitative comparison with the many theoretical results on a much more detailed level than what was previously possible. For the process of transfer ionization in proton-helium collisions we have determined the velocity dependence of the Thomas transfer ionization cross section to be the expected vp-11 when the projectile velocity, vp, is sufficiently high. Further, we have determined the velocity-dependent probability for shake-off of the second electron from helium provided that the first one is transferred in a kinematic capture process. Finally, we have considered collisions between protons and hydrogen molecules. Here we have found a strong variation in the cross section for transfer and excitation processes when the angle between the direction of the incoming projectile and the internuclear axis of the target molecule is varied. The variation can be explained as a result of quantum mechanical interference related to the two indistinguishable atomic centers of the molecule.
14

Ion-atom collisions at relativistic and non-relativistic energies

Lee, R. J. S. January 2001 (has links)
No description available.
15

Experimental studies of ion-neutral chemistry related to the extraterrestrial environment : a thesis presented for the degree of Doctor of Philosophy in Chemistry in the University of Canterbury /

Edwards, Samuel Joseph. January 2009 (has links)
Thesis (Ph. D.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references (p. 172-183). Also available via the World Wide Web.
16

Three-body dynamics in single ionization of atomic hydrogen by 75 keV proton impact

LaForge, Aaron Christopher, January 2010 (has links) (PDF)
Thesis (Ph. D.)--Missouri University of Science and Technology, 2010. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed April 21, 2010) Includes bibliographical references (p. 82-87).
17

Electron and laser interactions with positive ions

McKenna, Paul January 2000 (has links)
No description available.
18

Transfert d'atomes d'hydrogène vers la cathode d'un arc réducteur de composition argon-hydrogène /

Elayoubi, Mustapha. January 1989 (has links)
Mémoire (M.Sc.A)--Université du Québec à Chicoutimi, 1989. / Document électronique également accessible en format PDF. CaQCU

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