Systematics of K and L x-ray production by 6 to 15 MeV/u heavy ion bombardment /
The dependence of Cu (target atom) K-shell vacancy production cross sections on projectile atomic number was investigated. A combination of energy and wavelength dispersive x-ray spectrometry was used to measure Cu K x-ray production cross sections and to determine the appropriate fluorescence yield...
| Main Author: | |
|---|---|
| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1999.
|
| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=733677601&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The dependence of Cu (target atom) K-shell vacancy production cross sections on projectile atomic number was investigated. A combination of energy and wavelength dispersive x-ray spectrometry was used to measure Cu K x-ray production cross sections and to determine the appropriate fluorescence yields for converting them to vacancy production cross sections. The wavelength dispersive spectra revealed the presence of sizable contributions from predominately single-ionization mechanisms not directly associated with the ion-atom interactions. The cross sections for Z₁ > 24 fall far below a Z₁² scaling law and are greatly overestimated by the ECPSSR theory. Wavelength dispersive spectrometry was also used to explore the target atomic number, projectile atomic number and projectile velocity dependence of L x-ray structure. Measurements of the angular dependence of the emitted spectra revealed no alignment of the L nutshells in these multiply ionized atoms. Dirac-Fock calculations of x-ray energies were performed and a parabolic interpolation procedure was developed to determine the expected energies of the x-ray satellites. A semi-empirical model was developed to predict the numbers of electronic vacancies created in the collision. The results of the wavelength dispersive measurements of both K and L x rays from solid targets revealed an unexpected saturation in the number of vacancies produced in a single collision at just over 1/2 of the available electrons in the L and M shells, respectively. |
|---|---|
| Item Description: | Vita. "Major Subject: Chemistry". In title numerals are used. |
| Physical Description: | xviii, 260 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 187-192). |