Stabilization of autoionizing states

Author

Heider Naim Ereifej

Abstract

"In the first experiment, the stabilization process of doubly excited states in Barium was examined for the case when a laser field was used to induce stimulated emission of the excited core electron. Stabilization is referred to all the atoms that form a singly excited neutral state after being in a doubly excited autoionizing state. Relative to pure fluorescence, the application of a laser pulse which was long relative to the autoionization lifetime was found to increase the number of atoms that were stabilized. Shake-up spectra in which the principal quantum number of both electrons changes during the stimulated emission process was also clearly demonstrated.

In the second experiment, a short laser pulse (short relative to the autoionization lifetime) was used to stimulate doubly excited Calcium atoms to form a stable configuration. Because the stimulated emission process happens on a fast time scale, more atoms were stabilized before they had a chance to autoionize. As a result, much larger enhancement factors were achieved.

In the third and final experiment, a direct measurement of the oscillations between degenerate bound state configurations in a rapidly autoionizing system was clearly demonstrated. Because of the short pulse excitation, the atom was prepared in one of many accessible two-electron configurations. This state of the atom was not an energy eigenstate but a non-stationary wavepacket. The evolution of these wavepackets was monitored by changing the timing between the exciting "pump" laser and the stimulating "probe" laser"--Abstract, page iv.

Advisor(s)

Story, J. Greg

Committee Member(s)

DuBois, R. D. (Robert D.), 1951-
Peacher, Jerry
Schmitt, John L.
Watkins, Steve Eugene, 1960-

Department(s)

Physics

Degree Name

Ph. D. in Physics

Comments

The author acknowledges the financial support of the National Science Foundation (NSF) and the University of Missouri Research Board.

Publisher

University of Missouri--Rolla

Publication Date

Spring 2000

Journal article titles appearing in thesis/dissertation

• Laser induced stabilization of autoionizing states
• Short pulse laser induced stabilization of autoionizing states
• A direct measurement of oscillations between degenerate two-electron bound state configurations in a rapidly autoionizing system

Pagination

x, 77 pages

Note about bibliography

Includes bibliographical references.

Rights

© 2000 Heider Naim Ereifej, All rights reserved.

Document Type

Dissertation - Restricted Access

File Type

text

Language

English

Thesis Number

T 7763

Print OCLC #

45657592

Electronic OCLC #

1114603984

Link to Catalog Record

Electronic access to the full-text of this document is restricted to Missouri S&T users. Otherwise, request this publication directly from Missouri S&T Library or contact your local library.

Recommended Citation

Ereifej, Heider Naim, "Stabilization of autoionizing states" (2000). Doctoral Dissertations. 1348.
https://scholarsmine.mst.edu/doctoral_dissertations/1348